indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article doi: 10.26554/ijems.2017.1.1.11-1411 received: 10 september 2017 accepted: 17 november 2017 *corresponding author email: indah_chemistry@yahoo.com adsorption kinetics of fe and mn with using fly ash from pt semen baturaja in acid mine drainage indah purnamasari1*, endang supraptiah1 1chemical engineering department, sriwijaya state polytechnic, jl. srijaya negara bukit besar, palembang 30319 abstract one used method to reduce heavy metal ions in acid mine drainage is to adsorb them by coal fly ash. this research aimed to study the isotherms equilibrium and the adsorpstion kinetics that fit with decreasing metals ion. acid mine draigane and fly ash were charge into batch coloumn adsorption with specified comparison. variables investigated were dactivated and activated fly ash, adsorption times (0, 20, 30, 40,50, and 60 minutes), adsorben weights (10, 20, 30, 40, 50, and 60 gram), and ph (1, 3, 5, 7, and 9). the results showed that fly ash can be used to reduce the levels of heavy metal ions fe and mn. coal fly ash adsorption model of acid mine drainagefits to freundlich adsorption isotherm in all condition. first order pseudo kinetics model is suitable for fe and mn adsorption processes. the value of adsorption rate constants of fe and mn (deactivated fly ash) were 0.2388 min-1 with r2 = 0.4455 and 0.4173 min-1 with r2 = 0.9781, fe and mn (activated fly ash) 0.5043 min-1 with r2= 1 and 0.2027 min-1 with r2= 0.8803. keywords: sintetics adsorption, acid mine drainage, fly ash, langmuir isotherm, freundlich isotherm 1. introduction increased coal demand has fueled increased coal exploration [1]. coal exploration by mining will produce mine wastewater. mine wastewater consists mainly of acid mine drainage and mud. the coal mine wastewater contains residues, causes acidity, and ions metal which if disposed directly into the environment will cause environmental damage. in addition, coal is also one of the mining materials used for steam power plants. the process of burning coal to generate steam power will produce residual combustion called fly ash and bottom ash which if not utilized properly, will interfere with human health and the environment. the components in fly ash vary depending on the coal source being burned, but all fly ash contain silicon dioxide (sio2) and calcium oxide (cao) [2]. the various uses of fly ash are as raw materials for cement production and construction materials [3]. as an adsorbent, fly ash has advantages of being economical, good for gas or liquid waste treatment [4], and capable of absorbing heavy metals in wastewater [5]. the condition of silica and alumina in fly ash is large enough to allow fly ash to be used as a potential adsorbent. these mean many active centers of solid surface that can interact with adsorbate. adsorbent from fly ash has been widely used, such as fly ash is used as an adsorbent of co gas emissions in motor vehicles by varying the activation temperature of fly ash [6]. moreover, there was also the research about adsorption no2 gas by fly ash. the results showed that fly ash can absorb no2 gas with optimum within 5 minutes [7]. therefore, this research aimed to study fly ash that can be utilized as an adsorber of acid mine drainage, the happening phenomenon by determining the adsorption equilibrium, and its adsorption kinetics model. 1.1. adsorption isotherm adsorption is a phenomenon in which a quantity of gas or solution is settled on a surface. for example contact between gas and solution in a metal. the interaction that occurs will cause the metal surface properties to change. the gas or the attracted solution is called adsorbate while the metal surface is called the adsorbent [8]. there are commonly two kinds of isotherm adsorption models are langmuir isotherms and freundlich isotherms. 1.2.adsorption of langmuir isotherms the following model of langmuir equation : qc = (qb ce)/(1+bce) (1) the linear form of the equation is expressed in ce/qe = 1/qb + ce/q (2) where qe is the amount of adsorbate that adsorbed per unit of adsorbent weight (mg g-1), ce is the concentration of adsorbate in equilibrium (mgl-1), whereas q and b are langmuir constants. 1.3. adsorption of freundlich isotherms the following model of freundlich equation : qe= kf c1/n (3) the linear form of the equation follow in the following equation: log qe = log kf + 1/n log ce (4) kf and n are the adsorption capacity and the adsorption intensity. purnamasari et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 11-14 doi: 10.26554/ijems.2017.1.1.11-1412 the kf and n values are derived from the intercept and slope of the graph plot between the log qe versus log ce. 1.4.kinetics adsorption models 1.4.1. adsorption kinetics first order pseudo dq/dt=k (qe-q) (5) where q and qe are the amount of adsorbed substance per unit of adsorbent mass (mmol g-1) at time t and at equilibrium, k is the first order adsorption kinetics constant (min-1). 1.4.2. adsorption kinetics second order pseudo 2( )e dq k q q dt = − (6) where k is the second order adsorption kinetics constant. 2. experimental section 2.1. materials acid mine drainage obtained from pt bukit asam which is acidic water contained iron (fe) and mangan (mn) solution. adsorbent used is fly ash from pt semen baturaja measuring 212 μm which is not activated and activated with naoh. 2.2.methods acid mine drainage and fly ash (not activated and activated) are charged into adsorbtion column, the adsorption process is carried out in batch (with various observations variables). after sendimentation, samples were taken and analized with aas spectrophotometer 3. results and discussion the decreasing concentrations of fe and mn in various conditions are listed in table 1-4. 3.1. langmuir and freundlich isotherms adsorption 3.1.1. langmuir and freundlich isotherms on adsorption times langmuir and freundlich isotherm parameters obtained as the effect of adsorption time are shown in table 5 and figure 1 and 2. from figure1 we got the linearity relation to calculate the langmuir constant and the greatest determination coefficient (r2) [9]. the constant langmuir value for fe (deactivated), fe (activated), mn (deactivated), and mn (activated) on adsorption times are -0.0010 l/mg, -0.001 l/mg, -0.00005 l/mg, and -0.00003 l/ mg while the best coefficient of determination is 0.9647 so that the langmuir isotherm model for time variation can be said that fe (deactivated) is suitable using langmuir isotherm model compared to others. the adsorption isotherm model appropriate for the data can be table 1. fe and mn metal content in acid mine drainage before treatment metals concentration (mg/l) fe 17.12 mn 8.68 table 2. concentration decreasing of fe and mn on adsorption times adsorption times (minutes) deactivated activated fe (mg/l) mn (mg/l) fe (mg/l) mn (mg/l) 10 0.18 0.07 0.19 0.007 20 0.13 0.01 0.08 0.007 30 0.17 0.007 0.12 0.04 40 0.09 0.007 0.15 0.03 50 0.11 0.007 0.16 0.01 60 0.19 0.007 0.27 0.007 table 3 . concentration decreasing of fe and mn on adsorbent weights adsorbent weights (gram) deactivated activated fe (mgw/l) mn (mg/l) fe (mg/l) mn (mg/l) 10 0.1 0.02 0.09 0.04 20 0.19 0.007 0.14 0.007 30 0.54 0.11 0.13 0.02 40 0.19 0.007 0.27 0.007 50 0.106 0.007 0.25 0.03 table 4. concentration decreasing of fe and mn on ph ph deactivated activated fe (mg/l) mn (mg/l) fe (mg/l) mn (mg/l) 1 0.18 0.007 0.13 0.01 3 0.16 0.007 0.18 0.007 5 0.09 0.007 0.18 0.007 7 0.19 0.007 0.27 0.007 9 0.13 0.007 0.2 0.007 figure 1. langmuir isotherms modwe on adsorption times for: (a) fe (deactivated fly ash), (b) fe (activated fly ash), (c) mn (deactivated fly ash), and (d) mn (activated fly ash) purnamasari et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 11-14 doi: 10.26554/ijems.2017.1.1.11-1413 determined by looking at the largest determinant coefficient (r2), but the research data has no correspondence with the langmuir model. it can be seen in table 1, the langmuir constant value in fe (activated) and fe (deactivated) and the mn constant value (deactivated) and mn (activated) on the langmuir isotherms are negative. the decrease of fe and mn metal content over time has the best level of conformity with freundlich isotherms model. 3.1.2. langmuir and freundlich isotherms on adsorbent weights langmuir and freundlich isotherm parameters obtained as the effect of adsorption time are shown in table 6. from table 6, fe (activated) is better than fe (deactivated) because it has a coefficient of determination (r2)> 0.6 it indicates that fe (activated) is suitable using the langmuir equation while for mn (deactivated) and mn (activated) the value of coefficient of determination (r2) less than 0.6 so that linear line is not significant at this weight variation. this may happen because the adsorbent is not able to absorb mn metal inside the adsorbate. for isotherms fereundlich model, fe (deactivated) has a constant value smaller than fe (activated) so that freundlich isotherm model approach more to coefficient of determination (r2) where in this case fe (activated) has a coefficient of determination greater than 0.6 is 0, 8261 and it can be said that fe metals are absorbed by more adsorbents. fe (deactivated) was possible during the study weights variation was not uniformly the same with volume of adsorbate so that when absorption by iron adsorbents in the adsorbate was saturated and impacted data obtained. while in mn (deactivated) has a coefficient of determination (r2) 0.0375 and on metal mn (activated) has a coefficient of determination (r2) 0.0752, from the determination coefficient can be known that mn (deactivated) or mn (activated) is not linear because the determinant coefficient is less than 0.6. this may occur because the variation in the weight of the amount of adsorbent is not able to absorb mn metal, other factors can also occur during the study such as the solution is too long contact with the adsorbent, imperfect filtration, there is still adsorbent deposits when it gets the results to be analyzed so that with too many adsorbent contacts with adsorbate result in the metal contained in the adsorbate already in saturation or equilibrium state. however, in this weight variation the most suitable isotherm model is freundlich isotherm. 3.1.3. langmuir and freundlich isotherms on ph solutions langmuir and freundlich isotherm parameters obtained as the effect of adsorption time are shown in table 7. table 7 showed that fe (activated) has a coefficient of determination of 0.9276 greater than 0.6 with a langmuir constant of -0.0019 l/mg. from the difference of both can be seen that fe (deactivated) was better than fe (activated). mn (activated) has a determination coefficient of 1 with langmuir constant of -0.000009 l/mg. for the langmuir equation model the most suitable variation of ph is mn (activated) because mn in acid mine drainage in perfectly adsorption by activated fly ash. figure 2. freundlich isotherms model on adsorption times for: (a) fe (deactivated fly ash), (b) fe (activated fly ash), (c) mn (deactivated fly ash), (d) mn (activated fly ash) tabel 5. langmuir and freundlich isotherms parameters on adsorption times. parameter langmuir freundlich kl (l/mg) qm (mg/g) r2 kf (mg/g) n r2 fe (deactivated) -0.001 0.042 0,9647 23.94 -125 0.992 fe (activated) -0.001 0.042 0,8343 23.99 -109.8 0.955 mn (deactivated) -0.000 0.022 0,9183 46.84 -312.5 0.988 mn (activated) -0.000 0.022 0,9242 46.59 -476.1 0.980 table 6. langmuir and freundlich isotherms on adsorbent weights parameters langmuir freundlich kl (l/mg) qm (mg/gr) r2 kf (mg/gr) n r2 fe (deactivated) -0.042 0.565 0.122 15.89 -59.52 0.001 fe (activated) -0.077 0.027 0.847 150.07 -0.8 0.826 mn deactivated) 0.006 0.045 0.205 19.61 9.78 0.038 mn (activated) 0.000 0.030 0.002 12.48 4.67 0.075 table 7.langmuir and freundlich isotherms adsorption of ph parameters langmuir freundlich kl (l/mg) qm (mg/g) r 2 kf (mg/g) n r 2 fe (deactivated) -0.001 0.042 0.959 23.93 -128.2 0.989 fe (activated) -0.002 0.042 0.928 24.08 -88.49 0.982 mn (deactivated) mn(activated) -0.000 0.022 1 46.34 -1000 1 table 8. kinetics adsorption constant in pseudo first order and pseudo second order parameters k1(min -1) r2 k2 (g.mmol1.min-1) r2 fe (deactivated) 0.239 0.446 15721 0.33 fe (activated) 0.504 1 55868 1 mn (deactivated) 0.417 0.978 733080 0.995 mn (activated) 0.203 0.880 111711 0.548 purnamasari et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 11-14 doi: 10.26554/ijems.2017.1.1.11-1414 freundlich isotherms are often used in adsorption of liquids. the assumption of this isotherm is based that there is a heterogeneous surface with some type of active adsorption center. freundlich isotherm also explains that the surface adsorption process is heterogeneous where not all of the adsorbent surfaces have adsorption power. this is evident from the results in table 7, where the resulting r2 for each parameter is almost 1. in the ph variation, the freundlich isotherms are considered the most suitable to describe the occuring adsorption. 3.2. kinetics adsorption the kinetic adsoprtion constant of pseudo order are listed in table 8. from table 8 that is known the largest value of k1 in fe (activated fly ash) is 0.5043 min-1that in the pseudo first order kinetics model. in the pseudo-second-order kinetics model, the largest k2 values were 737080 g.mmol -1 min-1 in mn (deactivated), and 111711 g.mmol-1.min-1 in mn (activated). the adsorption kinetics satisfies the pseudo first order adsorption kinetics because it was seen in r2 value because in the second order kinetics obtained for fe (deactivated) and mn (activated) tends to be smaller when compared to the first order adsorption kinetics model [10] 4. conclusion based on experimental results, fly ash can be used to reduce the levels of heavy metal ions fe and mn. coal fly ash adsorption model of acid mine drainage fits to freundlich adsorption isotherm in all condition. first order pseudo model kinetics is suitable for fe and mn adsorption processes. the value of adsorpsi rate constants vary around : fe and mn (deactivated fly ash) 0.2388 min-1 with r2 = 0.4455 and 0.4173 min-1 with r2 = 0.9781, fe and mn (activated fly ash) 0.5043 min-1 with r2= 1 and 0.2027 min-1 with r2= 0.8803. acknowledgement the authors are grateful to kemenristekdikti, in supporting this research activity. special thank is attributed to pt semen baturaja and pt bukit asam, which providefly ash and acid mine drainage for this research. references [1] anonim. kajianekonomi regional provinsi sumatera selatan. kantor perwakilan bank indonesia wilayah vii, 2014. [2] mufrodi. z. modifikasi limbah abu terbang sebagai material baru adsorben, 2010. [3] accessed from :http://repository.upnyk.ac.id606163. pdf/ on 21 june 2017. [4] jumaeri, w. astuti, and w.t.p. lestari. 2007. preparasi dan karakterisasi zeolit dari abu layang batubara secara alkali hidrotermal. reaktor. 11(1). pp 38-44. [5] juniar, h., said, m., haryati, s., faizal, m., 2016. removal of cod and tss from dye solution using sand filtration and adsorption, indonesian journal of fundamental and applied chemistry. 1(3). pp 67-71. [6] mohan,s. and gandhimathi. r. 2009. removal of heavy metal ions from municipal solid waste leachate using coal fly ash as an adsorbent. journal of hazardous materials. 169. pp 351-359. [7] lasryza, a. and sawitri. d. 2012. pemanfaatan fly ash batubara sebagai adsorben emisi gas co pada kendaraan bermotor. jurnal teknik pomits. 1(1). pp 1-6. [8] lestari. y.t. pemanfaatan limbah abu terbang (fly ash) batubara sebagai adsorben untuk penentuan kadar gas no2 di udara. jurusan kimia, fakultas mipa, universitas jember, jember, 2013. [9] cash. e.m. surface chemistry. oxford university press, oxford, usa, 2001. [10] vitasari, d., lystanto, p.a., kusmiyati, and fuadi. a.m. kinetika dantermodinamika adsorpsi cu2+ dengan adsorben karbon aktif arang batubara”. simposium nasional rapi viii, 2009. [11] said, m., hasan, h.a., nor, m.t.m., and mohammad, a.w. 2016. removal of cod, tss and colour from palm oil mill effluent (pome) using montmorillonite. desalination and water treatment. 57. pp 10490–10497. title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper adsorption and regeneration of indonesian natural pumice for total chromium removal from aqueous solution shinta indah1*, denny helard1, fitria marchelly1, dean eka putri1 1 department of environmental engineering, faculty of engineering, university andalas, padang, indonesia, kampus unand limau manis, padang, west sumatera, indonesia 25163 *corresponding author e-mail: accountname@email.com abstract to investigate the potential of adsorption and regeneration of natural pumice from west sumatera indonesia for total chromium (cr) removal from aqueous solution, batch experiments in multiple adsorption-desorption cycles were performed. the results indicated that the optimum condition of total cr removal were 3 of ph solution, 0.3 g/l of adsorbent dose, 60 min of contact time of adsorption, < 63 µm of diameter of adsorbent, and 1 mg/l of total cr initial concentration with 2.226 mg cr/g pumice of total cr uptake. the experimental data obtained were fitted with the freundlich adsorption isotherm within the concentration range studied. desorption efficiencies for total cr ions by using 0.1 m hcl as desorbing agent were in the range of 31-32%. although complete desorption were not attained, the natural pumice could be sufficiently reused up to 3 cycles of adsorptiondesorption with increasing trend in total cr uptake that may due to the surface modification of natural pumice caused by hcl. overall results revealed that easy availability of natural pumice as local mineral in west sumatra, indonesia and its ability to adsorb and retain total cr will create more interest to develop new natural adsorption method of pollutant removal from solution. keywords adsorption; desorption; natural pumice; regeneration; total chromium received: 12 february 2018, accepted: 16 may 2018 https://doi.org/10.26554/ijems.2018.2.2.30-27 1. introduction chromium is an essential element that is required in small amounts for carbohydrate metabolism, but becomes toxic at higher concentrations. chromium compounds are environmental pollutants occurring in soil, water and industrial e�uents because they are widely used in many industrial activities. in the natural environment, chromium is present in two stable oxidation states, cr(iii) and cr(vi), where the ratio of the two compounds varies depending on ph value, redox potentials, total chromium concentration and redox reaction kinetics. cr(vi) is highly toxic, mutagenic, carcinogenic and teratogenic. cr(iii) is much less toxic and mutagenic than cr(vi), but long-term exposure to high cr(iii) concentrations may cause allergic skin reactions, cancer and dna damage (malarvizhi et al., 2010; wang et al., 2014). because chromium consists of variable oxidation states in water the guideline value set by world health organization (who) regards total chromium concentration, this value is set to 0.05 ppm. therefore, it is highly imperative to treat the water containing chromium before its discharge. various treatment techniques including oxidation, reduction, electro-chemical precipitation, ultra�ltration, ion exchange, reverse osmosis and adsorption have been employed to remove chromium in water and wastewater (rengaraj et al., 2001; yurlova et al., 2002). adsorption on solid surfaces is the most common one since it is easy to be applied, has a simple design, and insensitive to toxic substances. adsorption also o�ers selectivity in removing low levels of heavy metals from dilute solutions and environmental friendly if combined with appropriate adsorbent and regeneration steps (bingöl et al., 2012; indah et al., 2017). many e�orts are being made continuously to develop new, low cost and e�cient adsorbents for removal of metals including chromium. over the years, the role played by adsorbents in water and wastewater treatment had been critically and elaborately investigated. several low cost adsorbents from agricultural wastes such as rice husk ash (zhang et al., 2014) and maize husk (indah et al., 2016) have been used as adsorbent. moreover, the potential the use of natural materials or local minerals such as zeolite (motsi et al., 2009) bentonite (melichová and hromada, 2012), and pumice (sepehr et al., 2014; indah et al., 2017) also have been widely considered because of better performance and low cost of these materials. among these natural materials, pumice which is a volcanic stone and can be found in many regions of the world has a low weight and a porous structure (up to 85%). because of its micro-porous structure, pumice has a high speci�c surface area, https://doi.org/10.26554/ijems.2018.2.2.30-27 indah et. al. indonesian journal of environmental management and sustainability, 2 (2018) 30-27 so that, recently, pumice also has been used as adsorbent for pollutant removal from water and wastewater (heibati et al., 2014). on the other hands, despite the capability of adsorbents to remove pollutant in the water, the used adsorbent may generate a problem to environment because they have to be discarded after it becomes exhausted. in addition, the utilization of mineral like natural pumice as adsorbent may reduce the availability of natural resources. therefore, the regeneration and reuse of the adsorbents is important to make the operation environmental friendly and minimize the requirement of adsorbent. in this sense, desorption and reutilization of the adsorbents in adsorption–desorption cycles could help in reducing the residues. however, so, far, there is only limited investigations on the adsorption and desorption as well as regeneration of natural pumice to remove pollutant in water or wastewater. due to several advantages of the pumice and its accessibility in indonesia, the main objective of this study was to investigate its e�ectiveness for the removal of total chromium at various experimental conditions and its possibility to reuse after metal desorption. laboratory batch experiments were performed to determine optimal ph, dose of adsorbent, contact time, diameter of adsorbent, initial concentration of chromium and the adsorption capacity of pumice. furthermore, in order to study regeneration ability of the natural pumice, sequential adsorption-desorption cycles were conducted 3 times using the same adsorbent. 2. experimental section 2.1 preparation of adsorbent natural pumice sample were obtained from riverside of sungai pasak, west sumatera, indonesia as byproduct of the process of sand mining in that area. pumice samples were washed with distilled water several times and dried out at room temperature, then crushed and sieved in order to obtain the desired particle size fractions. energy dispersive x-ray (edx) spectroscopy was employed to get information on the oxide content of the natural pumice. a scanning electron microscopy (sem, model s-3400n, hitachi, japan) was performed to observe the surface morphology of pumice. 2.2 batch adsorption experiment batch adsorption experiment were conducted at room temperature (25°c) by varying ph, dose of adsorbent, contact time, diameter of adsorbent and initial concentration of total chromium. in each experiment, in 500 ml erlenmeyer �asks with 100 ml of chromium solutions was contacted with pumice and gently agitated at 100 rpm. after a period of time, the mixture was �ltered by using whatman’s �lter paper no 42 and the total chromium concentration in the �ltrate was measured by atomic absorption spectrometry (rayleigh wfx 320, china). the amount of total chromium adsorbed by the pumice was generated as the di�erence between the initial and �nal concentration of the solutions. all experiments were performed in triplicate, and results provided are accordingly the averaged values of replicate tests. the adsorption capacity of total chromium adsorbed (qe, (mg/g)) can be calculated using the following equation. qe = co −ce w ·v (1) where co is the initial concentration of total chromium (mg/l), ce is the equilibrium concentration of total chromium g(mg/l), v is the volume of the solution (l), andw is the mass of the pumice (g). 2.3 batch desoprtion experiment the desorption experiment was conducted using pumice with total chromium adsorbed on the surface at the end of the sorption experiment. samples were mixed with 0.1 m hcl (a 1:200 solid to solution ratio), shaken at 100 rpm for 60 min and at room temperature (25°c). afterwards, the mixture was �ltered by using whatman’s �lter paper no 42 and the total chromium concentration in the �ltrate was measured by atomic absorption spectrometry (rayleigh wfx 320, china). all experiments were repeated three times, and results presented are consequently the averaged values of replicate tests. the desorbed total chromium was calculated as percentage using equation (eq. (2)). desorption = concentrationof desorbedmetal concentrationof adsorbedmetal ·100 (2) 3. results and discussion 3.1 adsorbent characterization si, al and fe are the major elements in natural pumice from sungai pasak, as shown in table 1 as determined by edx. other elements, except k, ca, na and mg were present in relatively smaller amounts (less than 3%). the elemental compositions of the pumice also indicate the absence of hazardous or carcinogenic substances, thus the pumice are considered appropriate as adsorbent to treat polluted water. the sem image showed the surface morphology of natural pumice from sungai pasak, west sumatra was displayed in figure 1. the image denoted that the pumice had a highly porous, cellular, smooth surface, and irregular texture with larger cavities, which serves suitable sites for adsorption. 3.2 e�ect of ph many studies have proved that ph is one of the most important parameters having an in�uence on the adsorption capacity of adsorbent for heavy metal ions removal from the aqueous solutions. the e�ect of ph on the adsorption of total chromium onto the natural pumice was studied in the range of 2 6. figure 2 shows the total chromium uptake increased from 0.084 mg/g to 0.101 mg/g as ph increased from 2 to 3. the highest total chromium uptake was recorded at ph 3 and the total chromium uptake decreased as ph increased to 6. the result © 2018 the authors. page 31 of 37 indah et. al. indonesian journal of environmental management and sustainability, 2 (2018) 30-27 figure 1. sem micrograph of pumice from sungai pasak, west sumatra, indonesia table 1. elemental and oxide composition of natural pumice from sungai pasak, west sumatra, indonesia element % weight na 0.49 mg 0.06 al 3.89 si 32.56 k 2.41 ca 1.2 fe 3 revealed the removal of total chromium from aqueous solution by adsorption is highly dependent on the ph of the solution, which a�ects the surface charge of the adsorbent. at low ph, the surface of the natural pumice becomes protonated favoring the strong electrostatic attraction between the adsorbent and chromium anions. however, at higher ph, the binding sites of adsorbent are deprotonated and causes the increasing negatively charged sites on the adsorbent surface and this is no longer favorable to anionic chromium adsorption. thus, the optimum ph for adsorption of total chromium onto the natural pumice was observed at ph 3. similar �nding on ph trend has been reported in adsorption of chromium studies by other researchers (sepehr et al., 2014; tytłak et al., 2014). above all the following experiments were carried out with ph values of 3. figure 2. e�ect of ph on total cr uptake onto pumice (chromium concentration = 0.05 mg/l; adsorbent dose = 0.3 g/l; diameter of adsorbent = < 63 µm; contact time = 60 min). data represent averages of triplicates ± se. 3.3 e�ect of adsorbent dose the di�erent doses of the pumice (0.3, 1.0, 3.0, 10 and 30 g/l) were studied to study the e�ect on chromium adsorption. the experiment was performed at room temperature, 3 of ph, 60 minutes of contact time and the initial concentration of chromium was �xed as 0.05 mg/l (figure 3). the results revealed that the chromium uptake decreased as the adsorbent dose increased. the total chromium uptake decreased from 0.043 mg/g to 0.001 mg/g by increasing the adsorbent dose from 0.3 to 30 g/l. as the adsorbent dose increased, the sorption sites remain unsaturated during the adsorption reaction and the agglomeration of adsorbent particles may occur that reducing the available external surface area and an increase in di�usional path length both of which contribute to decrease in amount adsorbed per unit mass. it is in accordance with our previous study and also con�rms observations by other investigators (indah et al., 2017; dhanakumar et al., 2007; yu et al., 2003). a maximum adsorption uptake at equilibrium of 0.043 mg cr/g was obtained for a pumice dose of 0.3 g/l. therefore, 0.3 g/l of adsorbent dose was determined to be the optimum dose in this study and above all the following experiments were carried out with this dose. 3.4 e�ect of contact time figure 4 depicts the e�ect of contact time on the adsorption of chromium onto natural pumice from aqueous solution. it was observed that the total cr uptake increased with increase in contact time up to 60 min. at this time, cr uptake reached 0.101 mg cr/g. however, at 90, 120 and 150 min of contact time, the cr uptake decreased to 0.09, 0.083 and 0.054 mg cr/g. the result indicated that the adsorption of total chromium is most rapid in the initial stages and gradually decreases until the equilibrium is reached. a large number of vacant surface sites of pumice that available for adsorption resulted the increasing © 2018 the authors. page 32 of 37 indah et. al. indonesian journal of environmental management and sustainability, 2 (2018) 30-27 cr uptake during the initial stage of sorption. after an interval in time, due to repulsive forces between the solute molecules on the adsorbent surface and the bulk phase, the remaining vacant surface sites of pumice were occupied (wongjunda and saueprasea, 2010). therefore, the equilibrium time for the removal of total chromium from aqueous solution by natural pumice is taken as 60 min and applied for further experiments. 3.5 e�ect of diameter of adsorbent to study the e�ect of particle sizes of natural pumice on the adsorption of total chromium, 5 variations of diameter of adsorbent representing the variation of particle size of adsorbent were applied. figure 5 shows that the increasing in the diameter of adsorbent resulted the decreasing in total cr uptake. the total cr uptake was decrease from 0.103 to 0.053 mg cr/g as diameter of adsorbent increase from <63 to 500-600 µm. the results revealed that the adsorption capacity depends on the size of adsorbent; as the diameter of adsorbent decreases, the adsorption capacity increases due to the wider exchange surface provided for the adsorption of the chromium ions. similar results were also documented in in the literature using other adsorbent [2, 17] (wang et al., 2014; lopez-nuñez et al., 2014). therefore <63 µm, as the smallest diameter of the 5 variations, was de�ned as the optimum diameter of adsorption and were applied for the further experiments. 3.6 e�ect of initial concentration the e�ect of initial concentration on total chromium adsorption onto natural pumice was investigated in the range 0.01-1 mg/l. as shown in figure 6, the total cr uptake increased from 0.012 to 2.226 mg cr/g, as the concentration was increased from 0.01 to 1 mg/l. it indicated that the actual amount of chromium ions adsorbed per unit mass of the natural pumice was increased with increasing in chromium ions concentrafigure 3. e�ect of adsorbent dose on total cr uptake onto pumice (chromium concentration = 0.05 mg/l; diameter of adsorbent = < 63 µm; ph = 3; contact time = 60 min). data represent averages of triplicates ± se figure 4. e�ect of contact time on total cr uptake onto pumice (chromium concentration = 0.05 mg/l; diameter of adsorbent = < 63 µm; ph = 3; adsorbent dose = 0.3 g/l). data represent averages of triplicates ± se. tion in the aqueous solution. an increase in initial chromium concentration may cause higher availability of chromium ions in the solution for removal and increase concentration gradient, which provides a stronger driving force to overcome mass transfer resistance of chromium ions between the aqueous and solid phases, resulting in higher probability of collision between chromium ions and active sites of natural pumice, thus leading to a higher total chromium uptake. the results clari�ed that higher initial concentration of chromium can enhance the adsorption process and the interaction between chromium and pumice as adsorbent. the result is consistent with the �nding by other researchers (malarvizhi et al., 2010; puentescárdenas et al., 2012). from the results it was also evident that the adsorption of total chromium onto natural pumice is dependent on initial metal concentration. under the conditions tested in this study, the highest total chromium uptake was 2.226 mg cr/g. 3.7 adsorption isotherm models the adsorption isotherm usually shows how the molecules are distributed between the liquid and the solid phases, at equilibrium during the adsorption process. a number of isotherm models have been developed to describe equilibrium relationships. linear forms of the langmuir, freundlich and elovich adsorption isotherm models ((3), (4) and (5), respectively) were used to verify the adsorption data: ce qe = ce qmax + 1 klqmax (3) logqe = logkf + 1 n logce (4) © 2018 the authors. page 33 of 37 indah et. al. indonesian journal of environmental management and sustainability, 2 (2018) 30-27 figure 5. e�ect of diameter of absorbent on total cr uptake onto pumice (chromium concentration = 0.05 mg/l; ph = 3; adsorbent dose = 0.3 g/l; contact time = 60 min). data represent averages of triplicates ± se. ln qe ce = lnkeqmax − qe qmax (5) where ce is the equilibrium concentration, qe is the amount of adsorbate adsorbed per unit mass of adsorbent, qmax is the maximum adsorption capacity, kl is the langmuir constant related to the adsorption rate, kf is the freundlich isotherm constant related to adsorption capacity, n is the freundlich isotherm constant related to adsorption intensity (indicating the favourability of the adsorption process) and ke is the elovich equilibrium constant. the langmuir model assumes uniform energies of adsorption onto the surface and no transmigration of the adsorbate along the plane of the surface. from the slopes and the intercepts, a linear �t to the langmuir equation yields langmuir constant (kl) and the maximum adsorption capacity (qmax), respectively (low, 1960). the freundlich model is based on the assumption that as the adsorbate concentration increases, the concentration of adsorbate on the adsorbent surface also increases. the linear form of the freundlich isotherm model yields a straight line. the slope and intercept of the obtained �t are used to calculate the freundlich constants 1/n and kf (freundlich, 1907). the elovich model is based on a kinetic principle assuming that the adsorption sites increase exponentially with adsorption, which implies a multilayer adsorption. the elovich maximum adsorption capacity and elovich constant can be calculated from the slopes and the intercepts of the plot of ln(qe/ce)versus qe (elovich and larinov, 1962). the applicability of the isotherm equations to describe the adsorption process was judged based on the maximum value of adsorption and correlation coe�cients (r2) which are a measure of goodness of �t. to determine the adsorption isotherm of total chromium adsorption onto natural pumice, the initial total chromium figure 6. e�ect of initial concentration on total cr uptake onto pumice (ph = 3; adsorbent dose = 0.3 g/l; contact time = 60 min; diameter of adsorbent = < 63 µm). data represent averages of triplicates ± se. table 2. isotherm model constants for adsorption of total chromium onto natural pumice isotherm constants r2 langmuir qmax (mg/g) kl (l/mg) 0.687-1 -2.31 freundlich 1/n kf (l/g) 0.99 1.33 9.25 elovich qmax (mg/g) ke (l/mg) 0.746-1.98 0.63 concentration was varied in the interval ranging from 0.01 to 1 mg/l with 3 of ph and 0.3 g/l of adsorbent dose. figure 7 shows the langmuir, freundlich and elovich isotherm plots and table 2 presents the isotherm model constants for the adsorption. data in table 2 show that the freundlich isotherm model presents the highest r2 value (0.990) indicated the model �tted well with the equilibrium data, compared with langmuir and elovich isotherm models. it revealed that the adsorption of total chromium onto natural pumice is multilayer sorption and the adsorption occurred on the heterogeneous surface of pumice and the active sites of pumice have di�erent energy, as the freundlich isotherm model’s assumption [20]. as shown in table 2, for the langmuir model, the maximal value of adsorption qmax was negative, which re�ects the inadequacy of this model for explaining the adsorption process (alshabanat et al., 2013). from the freundlich isotherm model, the adsorption of total chromium onto natural pumice from sungai pasak resulted 9.25 mg cr/g of kf as adsorption capacity and 1.33 of 1/n. the 1/n value derived from the freundlich equation serves to describe the linearity of adsorption. typically, 1/n values range from 1 downwards. a higher value of n (smaller value of 1/n) implies an e�ective interac© 2018 the authors. page 34 of 37 indah et. al. indonesian journal of environmental management and sustainability, 2 (2018) 30-27 figure 7. langmuir (a), freundlich (b) and elovich (c) isotherm plots for the adsorption of cr onto natural pumice (cr concentration: 0.01-1 g/l; adsorbent dose: 0.3 g/l; contact time: 60 min; ph: 3) tion between the adsorbent and adsorbate. when 1/n < 1, it corresponds a normal l-type langmuir adsorption isotherm, while 1/n > 1 re�ects a co-operative adsorption (guo et al., 2016). since the value of 1/n from this study is 1.33, it indicate that co-operative adsorption may occur in the system, where adsorbed adsorbate has an e�ect on the adsorption of “new” adsorbate molecules. moreover, 1/n values of > 1 are indicative of s-type isotherms, according to the giles et al. (giles et al., 1960) classi�cation, indicating that adsorption becomes easier for increasing concentration. the s-type characterized �rst by a weak adsorption which then gradually increases suggests a weak surface interaction and competitive adsorbate-adsorbate interactions. the s curve of the adsorption isotherm generally re�ects strong competition between the solvent and the adsorbed species for the adsorbent surface sites. for this study, in order to make a stronger interaction between natural pumice as adsorbent and adsorbate, more attempts could be made, such as modify the surface of the adsorbent physically or chemically using thermal treatment, protonation or metal oxides impregnation (sepehr et al., 2014). 3.8 desorption study batch desorption experiments were conducted in order to investigate the mechanism of metal ion removal and recovery from metal-loaded adsorbent and also for the regeneration and recycling of spent adsorbents, which in turn may reduce operational cost and protect the environment from the problem of residues of the adsorbent. in addition, e�cient removal of loaded metal from the natural pumice was necessary to ensure its long term use for repeated adsorption-desorption cycles. the regeneration of the adsorbent is likely to be a key factor in figure 8. adsorption and desorption e�ciencies as well as total cr uptake onto pumice at 3 cycles of adsorption-desorption (ph = 3; adsorbent dose = 0.3 g/l; contact time = 60 min; diameter of adsorbent = <63 µm; chromium concentration = 1 mg/l). data represent averages of triplicates ± se accessing the potential of the adsorbent for commercial application. the capacity of natural pumice to adsorb total chromium ions was determined by repeating the adsorption-desorption experiments in three consecutive cycles by using 0.1 m hcl as desorbing agent. figure 8 shows the desorption e�ciencies for total chromium ions by using 0.1 m hcl as desorbing agent were in the range of 31-32%. a slight increase in desorption e�ciencies was observed (approximately 1 %) at the second desorption cycle (desorption 2) may due to the accumulation of total chromium ions that could not release at the second adsorption (adsorption 2). although complete desorption were not achieved, the result con�rmed that hcl can be used as desorbing and recovery agent. in desorption process, the residence time is very essential because the higher the residence time, the longer the contact between the desorbing agent and the metal loaded adsorbent, so that the desorption e�ciency may increase (d wankasi, 2005). desorption e�ciency of cr(vi) ion from natural pumice obtained from tikmeh dash reign, east azerbaijan, iran reached 94.3% after 300 min contact time with 1 m hcl (sepehr et al., 2014). in this study, the desorption time was 60 min. if the contact time is extended, it may be possible to reach 100% desorption. as shown in figure 8, the reuse of the remaining natural pumice in a second and third adsorption cycle increased the removal e�ciency of total chromium ions from 63.50% (adsorption 1) to 73.47% (adsorption 2) and 78.66% (adsorption 3). these results may be related to chemical changes in the natural pumice produced by acid solution (hcl) that used as desorbing agent. many researchers noti�ed that the interaction between acid solution like hcl and adsorbents can modify the adsorbents and improve their adsorption capacity. the acid solution can removal of impurities on the adsorbent surface, © 2018 the authors. page 35 of 37 indah et. al. indonesian journal of environmental management and sustainability, 2 (2018) 30-27 decrease the organic content, increase the porosity, breakdown of the cell wall or generation of new sorption active sites of the adsorbents (sepehr et al., 2014). these results de�ne that natural pumice from sungai pasak, west sumatra, indonesia can be su�ciently reused up to 3 cycles of adsorptiondesorption. 4. conclusions natural pumice from sungai pasak, west sumatra, indonesia, which is available in a great abundance, as by-product of the process of sand mining in that area, was examined to become an alternative low-cost adsorbent for the removal of total chromium in water. the natural pumice has a highly porous, smooth surface, cellular and irregular texture with larger cavities, which provides suitable sites for adsorption. from the batch experiments which were performed at ambient temperature (25◦c) and 100 rpm of agitation speed, it was found that the optimum condition of total chromium removal by natural pumice were 3 of ph solution, 0.3 g/l of adsorbent dose, 60 min of contact time of adsorption, <63 µm of diameter of adsorbent, and 1 mg/l of total cr concentration with 2.226 mg cr/g pumice of adsorption capacity. the result also revealed that the freundlich isotherm model �tted well with the equilibrium data within the concentration range studied as it presents higher r2 value than that of the langmuir and elovich isotherms. it denoted that the adsorption of total chromium onto natural pumice is multilayer sorption, the adsorption occurred on the heterogeneous surface of pumice and the active sites of pumice have di�erent energy. to maximize function and capability of adsorbent used and make the process environmental friendly, the regeneration and reuse of adsorbent were studied by desorption experiment. it was con�rmed that the exhausted natural pumice could be desorbed 31-32% by 0.1 m hcl. the used natural pumice also could be regenerated and reused up to three successive adsorption-desorption cycles with increasing trend in total cr uptake that may due to the surface modi�cation of natural pumice caused by hcl as acidic medium. overall study revealed that pumice from sungai pasak could be a promising adsorbent for total chromium removal from water. 5. acknowledgement the authors would like to thank faculty of engineering, universitas andalas, indonesia (grand no. 045/un16.09.d/pl/2017) for supporting this work references alshabanat, m., g. alsenani, and r. almufarij (2013). removal of crystal violet dye from aqueous solutions onto date palm fiber by adsorption technique. journal of chemistry, 2013; 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53–63 yurlova, l., a. kryvoruchko, and b. kornilovich (2002). removal of ni(ii) ions from wastewater by micellar-enhanced ultra�ltration. desalination, 144(1-3); 255–260 zhang, y., j. zhao, z. jiang, d. shan, and y. lu (2014). biosorption of fe(ii) and mn(ii) ions from aqueous solution by rice husk ash. biomed research international, 2014; 1–10 © 2018 the authors. page 37 of 37 introduction experimental section preparation of adsorbent batch adsorption experiment batch desoprtion experiment results and discussion adsorbent characterization effect of ph effect of adsorbent dose effect of contact time effect of diameter of adsorbent effect of initial concentration adsorption isotherm models desorption study conclusions acknowledgement indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article received: 3 november 20117 accepted:12 march 2018 *corresponding author email: doi: 10.26554/ijems.2018.2.11-1411 cfd analysis of flue gas streamline through varied of flow straightener inclination pramadhony1, dewi puspitasari2, ellyanie2, marwani2, rizki m. r. sihombing 3 1master program of mechanical engineering, sriwijaya university, palembang 30139, indonesia 2mechanical engineering departemnt, sriwijaya university, inderalaya, oi, 30662, indonesia 3undergradulate program of mechanical engineering, sriwijaya university, inderalaya, oi 30662, indonesia abstract air emission, generated by industrial sector, is one of the main contributors of ambient air quality degradation. in order to minimize the impact to its surrounding, the company regularly should conduct an air emission monitoring activity by measuring the hazardous compound concentration. the sample should be taken in a reference plane located two diameter from the outlet. the sampling of air emission by using isokinetic method cannot be conducted when the swirling flow is existed; the streamline is also should be uniform and vertical. flow straightener with difference inclination angles, 0°, 15°, and 30°, are suggested to condition the streamline and fulfill the requirements. a computational simulation conditions with no flow straightener and with three flow straighteners are conducted to overview the influence of flow straightener inclination. based on the analysis these inclinations are effectively improving the uniformity of velocity at reference plane. in other side these inclinations are causing the increasing of helicity as well as streamline inclination. keyword: flow straightener, inclination angle, helicity 1. introduction industrial sector is one of the main emission contributors in indonesia. one of processes is generated by the combustion process. the amount of emission load is determined by the amount of fuel and the quality of equipment used. in 2014 industrial sector is became the largest consumer of energy with a percentage of 48% [1]. considering the significant impact, the government has been regulating the industrial sector to implement the monitoring/ measurement of air emission quality. this study is aimed to analyze the chimney which it’s sampling point does not meet the 8d-2d criteria, where the chimney has 6d of height. the sampling point/reference plane is measured at some distances from the outlet, they are: 2d, 1.5d and 1d from flue outlet. particulate emission is measured by isokinetic method, where the sample is taken at some points along two traverse points in the reference plane [2][3]. this method cannot be used when a swirling flow is occured. because of that a vertical flue gas flow with small angle streamline is required. this swirling flow can lead an error for the measurement of exhaust emissions, particularly related to the increasing of measurement deviation which is reaching of -7.05% [4]. in addition, the uniformity of flow should also be a concern, because the uniformity of velocity is influencing the measurenment result. 2. experimental section 2.1.geometry the geometry of chimney and flow straightener are created with the dimension is resemble to the previous research [5]. the flue gas is flowing through the inlet of chimney in a certain angle which produces a swirling flow. the flow straightener is designed with the height of 0.45 d stack diameter. the detail of dimension is shown in figure 1. the modification of flow straightener dimension is focused on the inclination angle of flow straightener. so the flow straightener is designed with inverse conical shape (downward position) with the angle of 0°, 15° and 30° as shown in figure 2. 2.2. cfd simulation having created the geometry, the next process is creating the hexahedron mesh. the size of mesh inside the flow straghtener is arrenged to be 0.015 d, while the others is arranged to be 0.050.1d. the flue gas flow and the influence of flow straightener installation was analyzed computationally by using software of fluent. the flue gas temperature is assumed 190°c and with the composition as shown in table 1 [6]. the average velocity of flue gas at the reference plane is set to be 17.5 m/s [7]. this simulation is using k-epsilon (reliazable) viscous model with pressure based solver. author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.11-1412 3. results and discussion 3.1. helicity helicity is a scalar value obtained by projecting the vorticity to axial velocity of flue gas as shown by the equation (1). the magnitude is directly proportional to the rotational / vortex movement that is occured inside the chimney. 𝐻𝐻 = (�̅�𝑉𝑥𝑥�⃗�𝑉 ) ⋅ �⃗�𝑉 ........................................(1) the resume of helicity value for four-simulation conditions is shown in table 2. while contour of helicity inside the chimney is shown in figure 3. according to simulation results, the installation of flow straightener is able to reduce helicity. the helicity reduction is inversely proportional to the increase of flow straightener inclination. this relation is occured due to the flow straightener inclination which tends to direct the flue gas to be rotated in counter-clockwise direction. 3.2 streamline inclination the streamline inclination of flue gas is shown by the angle between radial velocity and vertical velocity. the smaller angle indicates the more vertical streamline which is influencing the measurement accuracy as shown in table 3. the results show that 30° flow straightener produces the largest streamline angle with a maximum and average value of 8.01° and 1.62°. these results show that the more angle of flow straightener inclination, the more angle of flue gas streamline occured. these streamline inclinationss are directly proportional to the value of helicity. based on the contour of streamline inclination, the largest streamline angle is occured on the left side of chimney (x-negative axis) which generally has a lower vertical velocity. details of streamline inclination can be seen in figure 4. 3.3 the uniformity of velocity figure 5 shows the velocity profile of flue gas from inlet to outlet of chimney and the velocity profile in the reference plane where located at 2d, 1.5d and 1d from the outlet. this pictures show that by increasing the inclination angle of flow straightener, it will cause the increasing of velocity in the right side of chimney (x-positive axis). then it increases the uniformity of velocity. the method used to calculate the uniformity of velocity is taken by calculating the coefficient variation (cv). the coefficient of var (a) (b) figure 1. fixed dimensions of the geometry (a) chimney (b) flow straightener (a) (b) (c) figure 2. isometric figure of flow straightener (a) with 0o angle (b) with 15o angle, (c) with 30o angle. table 1. composition of flue gas [8] substance volume fraction (%) mass fraction (%) carbon dioxide (co2) 11 16,66 argon (ar) 1 1,32 water vapor (h2o) 6 3,97 oxygen (o2) 6 6,57 nitrogen (n2) 76 72,81 other substances near zero near zero table 2. helicity values at the reference planes simulation condition maximum helicity (m/s2) average helicity (m/s2) with no flow straightener 733.37 385.32 with 0° flow straightener 667.58 45.42 with 15° flow straightener 717.81 53.59 with 30° flow straightener 873.72 67.18 table 3. the maximum and average streamline inclination in reference plane simulation condition maximum (°) 2d from outlet 1.5d from outlet 1d from outlet with no flow straightener 43.34 38.84 35.57 with 0° flow straightener 6.42 5.16 2.97 with 15° flow straightener 7.09 3.98 3.07 with 30° flow straightener 8.01 4.6 3.29 simulation condition average (°) 2d from outlet 1.5d from outlet 1d from outlet with no flow straightener 17.47 16.46 16.05 with 0° flow straightener 1.41 0.97 0.78 with 15° flow straightener 1.45 0.98 0.78 with 30° flow straightener 1.62 1.01 0.82 author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.11-1413 iation is calculated by the following formula: 𝐶𝐶𝐶𝐶 = |𝑣𝑣−�̅�𝑣|�̅�𝑣 𝑥𝑥100%..................................(2) b y taking the average value of cv, then it obtain the cv value of each simulatin as shown in table. 4. based on the result, the 30° flow straightener is able to generate the most uniform velocity at the reference planes. these results also show that the closer plane to the chimney outlet, the more uniform velocity is obtained. conclusion computational simulations have been performed to exemine the effect of flow straightener inclination to the flue gas flow at the reference plane. the reference planes are located at a distance of 2, 1.5 and 1 times diameter of flue outlet. the velocity profile and streamline inclination are presented in contour form. meanwhile the uniformity of velocity is determined by calculating the average value of the coefficient of variation. based on the results, these modifications are effectively improving the uniformity of velocity in some reference planes. the best variation coefficient is generated by 30° flow straightener with value of 35.05% located 2d before outlet, 33.58 % located 1.5d before outlet and 32.37% located 1d before outlet. on the other hand the increasing of flow straightener inclination is causing the increasing of helicity. where this increasing of helicity is proportional to the increasing streamline inclination. the highest streamline inclination which is generated by 30° flow straightener is located in the area near chimney wall. since the inclination angle is relatively low and the emission measurement do not be taken in the area near to the wall, it is predicted that the stremline (a) (b) (c) (d) figure 3. the helicity contours from inlet to outlet of chimney (a) with no flow straightener, (b) with 0o flow straightener (c) with 15o flow straightener, (d) with 30o flow straightener. reference plane location 2d from outlet 1.5d from outlet 1d from outlet (a) (b) (c) (d) figure 4. the contour of streamline inclination at reference plane (a) with no flow straightener, (b) with 0o flow straightener (c) with 15o flow straightener, (d) with 30o flow straightener tabel 4. average of variation coefficient for each simulation simulation condition reference plane location (%) 2d from outlet 1.5d from outlet 1d from outlet with no flow straightener 21.61 18.54 16.4 0° with flow straightener 36.91 35.11 33.78 with 15° flow straightener 36.33 34.73 33.4 with 30° flow straightener 35.05 33.58 32.37 author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.11-1414 inclination do not give a significant impact on the measurement results. finally, experimental analysis is still needed to determine the accuracy of these particulate emissions measurements. acknowledgement we would like to thanks to dipa blu of sriwijaya university, ministry of research, technology and higher education, which has provided financial support in this research. references [1] bppt, “outlook energi indonesia 2016,” jakarta, 2016. [2] u. karnik, w. m. jungowski, and k. k. botros, “effect of turbulence on orifice ieter performance,” j. offshore mech. arct. eng., vol. 116, no. may 1994, pp. 77–85, 1994. [3] u.s. epa method 1, “sample and velocity traverses for stationary sources,” 1996. [4] j. j. s. shen, “characterization of swirling flow and its effects on orifice metering,” 1991. [5] a. scarabino, f. bacchi, r. j. filace, and m. raviculé, “computational fluid dynamic analysis of a heater chimney with and without a flow straightener,” j. sci. eng. res., vol. 2, no. 2, pp. 79–93, 2015. [6] v. seshendra and k. karri, “a theoretical investigation of efficiency enhancement in thermal power plants,” vol. 2012, no. august, pp. 106–113, 2012. [7] b. j. j. carter, r. l. petersen, and b. c. cochran, “designing exhaust systems to minimize energy costs,” vol. 47, no. 7, 2005. [8] r. zevenhoven and p. kilpinen, flue gases and fuel gases. 2001. (a) (b) (c) figure 5. contour of velocity profile (a) with no flow straightener, (b) with 0o flow straightener (c) with 15o flow straightener, (d) with 30o flow straightener indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article received: 27 october 2017 accepted: 9 february 2018 *corresponding author email: igusman@bukitasam.co.id doi: 10.26554/ijems.2018.2.1.7-107 energy efficiency and greenhouse gas emissions reduction through electrification program at tanjung enim mine business unit of pt bukit asam (persero) tbk. iko gusman1,pramudita triatmojo1, peni rostiarti1, bima arifiyanto1 1pt. bukit asam (persero) tbk. unit pertambangantanjungenim jalanparigi no.1-a kecamatanlawangkidul, kabupatenmuaraenim, sumatera selatan indonesia igusman@bukitasam.co.id abstract current global economic conditions have made the coal prices become uncertain. pt bukit asam (ptba) has taken corporate action by improving operational efficiency, cost control; develop coal diversification product and also optimization in the mining operation. one of the operational efficiency programs for cost control in mining operation system is the electrification program. this program changed mining operations previously dominated by fuel-based mining system transformed into an electricity-based mining system for an electricshovel continue with the conventional truck. implementation of mining systems with electric-based mining equipment divided into several stages for short-term and long-term targets. electrification program consist of 7 units electric shovel (pc3000-6e) and 40 units rigid dt (belaz75135) with target20 million bcm in 2017 located in banko west mine. ptba through the electrification program has succeeded in reducing energy consumption by 333,861.74 joule/years and reducing greenhouse gas emissions by 15,058.49 ton co2e/year. electrification program has successfully contributed for environmental sustainability by reducing energy consumption and greenhouse gas emissions in accordance with the vision of ptba into a world-class energy company that cares about the environment. keywords: electrification, mining system, energy consumption, greenhouse gas emission, ptba 1. introduction current global economic conditions have made the coal prices become uncertain. pt bukit asam (ptba) has quickly responded to these conditions by improving operational efficiency, cost control, diversifying export marketing including introducing focused mining patterns, while maintaining environmental sustainability. one of the operational efficiency programs for cost control and corporate development is electrification program where previously mining operations were dominated by fuel-based mining systems. implementation of mining systems with electric-based mining equipment is also designed through stages to adjust to short-term and long-term corporate targets and adjust to the readiness of equipment. in the framework of such development, ptba has invested in electricity-based mining equipment by utilizing its competency capacity in managing continuous mining systems and the potential of existing internal resources (mouth mine power plant) to reduce dependence on fuel consumption. electrification program has also proven to contribute to environmental sustainability, namely the reduction of energy consumption and greenhouse gas emissions, in accordance with the vision of ptba to be a world-class energy company that cares about the environment. 2. experimental method estimation of electricity consumption can be applied to a wide range of analyses that can be used to [1]: 1. perform or review prefeasibility level studies by using individual estimates or linking them for estimating requirements for vertical integrated mining operations 2. estimate the economic effects of changes in power rates and fuel costs on producing or planned mining facilities 3. estimate a component of greenhouse gas contributions produced by the energy source used to generate electricity consumed by a mining operations factor that affecting coal mine energy consumption, can be generated from many aspects such as operator practice, operating conditions and also equipment [2]. on the implementation, energy consumption in mine also varies due to the variation of the mine topography, mine equipment characteristics and operational practices. the diesel or electricity are used for operating dump trucks, author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.1.7-108 excavators, shovels, draglines, crushers, conveyors and pumps. based on benchmarking in gondegaon opencast mine, input energy profile for conventional opencast coal mine, electricity has annual energy consumption of 8.203 mu equivalent with 98.760 gj (36%) meanwhile diesel has annual energy consumption of 5.019 mu equivalent with 179.195 gj (64%) [3]. electrical equipment (electrification) program in pt. bukit asam is a new mining method which previously dominated by fuel-based mining systems. implementation of this program is done by implementing the main equipment of the electric digging tool (shovel) and combined with fuel-based truck. electrification is environmentally friendly program because it is proven to decrease energy consumption and decrease greenhouse gas emission. the calculation of this decrease is done by using comparison data of electrical-based mining equipment with fuel-based mining equipment. • electric digging tool (shovel) equipment used in conducting excavation activities using electric shovel pc 3000-6e • transportation (truck) the equipment used in carrying the hauling activity is dumptruck belaz-75135. figure 1. factors affecting coal mine energy consumption [2] figure 2. shovel pc 3000 equipment. specification of electric shovel pc 3000-6e: type : hydraulic shovels drive system : electric drive output power : 900 kw bucket capacity : 16,0 cum crowd force : 1100 kn break-out force : 1000 kn boom : 6,0 m stick : 4,3 m figure 3. belaz truck specification of dumptruck belaz-75135: nominal payload capacity : 110 metric ton : 120 short ton engine : cummins k1500e transmission : electrical transmission ratio : electric speed ratio up to 4726 torque nm control system : automatic control system top speed (km/h) : 48 front brakes : disk brake rear brakes : disk brake, resistor brake gross vehicle (operating weight) : 230.100 kg fuel refill, ltr : 1900 tires : 33.00 – 51 figure 4. electrification mining process author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.1.7-109 • electrification mining process electrification mining process is done by implementing the main equipment of the electric digging tool (shovel) and combined with fuel-based truck. results and discussion electrical equipment (electrification) conducted by ptba as an effort to maximize electrical energy from mine mouth steam power plant in tanjun enim mining unit. electrification is done by changing conventional mining method based on fuel into basedon electric energy. the mining method with the ipcc system has several advantages and disadvantages, the following explanation as listed in table 1. the results show that ipcc mining method with electrification has more advantages. electrification succeeded in reducing operating costs by 40% caused by the fuel savings due to switching to electricity. table 2 there are cost efficiency in pc 3000 electric of rp 37,900,162,944 for 7 units shovel electric operates and decreasing oil usage as much as 29.187 liters per year equivalent with rp. 1.208.904.636. cost efficiency of usage belaz truck 75135 amount rp. 30,423,069,440 for 40 units operates and decreasing oil usageas much70,883 liters per year equivalents with rp. 3,849,383,059,20. table 2 show the complete calculation. figure 5. mining system changes from the old mining system in pit crusher & conveyor (ipcc) system with electric equipment table 1. ipcc system advantages and disadvantages analysis ipcc system (shovel à crusher à conveyor àsp/sr/tls) advantages disadvantages 1. electricity cost (rp./kwh) 40% less cheaper than fuel (rp ./liter). 1. limitations of flexibility by using conveyor crusher. 2. reduce pollution of heavy equipment carbon emissions. 2. investment cost is higher than shovel & truck. 3. labor cost, maintenance cost and operating cost are relatively low and less than shovel & truck. 3. for the fully mobile type is resistant to weather, meanwhilesemi mobile is vulnerable to weather changes. 4. can cover the mining distance is relatively fluid and flexible. 5. suitable for soft-hard rock and oversize type of material. table 2. calculation of decreased energy consumption and emission reduction decription unit pc electric pc diesel liter / h 184.00 kwh / h 436.00 jam jalan / th 5212.00 5212.00 number of unit unit 7 7 ncv tj/liter 0.000036 fe co2 (diesel) kg/tj 74100 fe co2 (electric) kg co2 / kwh 0.749 co2 emission ton co2e / th 11,914.36 17,907.75 emission reductions ton co2e / th decription unit pc electric pc diesel liter / h 58.70 75.00 kwh / h jam jalan / th 5212.00 5212.00 jumlah unit unit 40 40 ncv tj/liter 0.000036 0.000036 fe co2 (diesel) kg/tj 74100 74100 co2 emission ton co2e / th 32,645.49 41,710.59 emission reductions ton co2e / th total emission reductions ton co2e / th information 5,993.39 9,065.10 15,058.49 emisi co2 (diesel) = ncv x fe x vol bbm emisi co2 (electric) = fe x kwh ncv1 diesel = 0,000036 tj/liter fe2 co2 (diesel) = 74.100 kg/tj fe3 co2 (electric) = 0,749 kg co2/kwh fe = emission factor ncv = heat values 1. national inventory guidance manual 2012, book 1 volume 1 use and procurement of energy table 2.2 2. national inventory guidance manual 2012, book 1 volume 1 use and procurement of energy table 2.3 3. letter of emission factor (dj-esdm), 2012 energy consumption energy consumption author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.1.7-1010 electrification also reduced energy consumption by 333.861,74 joule/years. decline in energy consumption is also followed by a decrease in greenhouse gas emissions of 15.058,49 ton co2/year. inefficiencies that affect electricity consumption in site can occur for many reasons. for example technical problems in hauling road design that decreasing total productivity unit. conclusion comparison of operational costs for the use of electric shovel energy (pc3000-6e) with pc3000 diesel is rp. 37,900,162,944 for 7 units shovel electric operates and decreased oil as much as 29.187 liters per year equivalent rp. 1,208,904,636.80. comparison of operational costs for the use of belaz 75135 fuel (electric drive) with an equivalent dumptruck (hd785) using mechanical drive is rp. 30,423,069,440 for 40 units of rt belaz 75135 operates and decreased oil asmuch as 70,883 liters per year equivalent rp.3,849,383,059,20. total energy savings from implementation of electrification program of 333.861.74 gjoule per year. total green house gas emission reductions from implementation of the electrification program of 15.058.49 ton co2e per year. there are opportunities to increasing efficiency by optimizing site conditions such as haul road design optimization to increase the productivity unit reference [1] bleiwas, estimates of electricity requirements for the recovery of mineral commodities, with examples applied to sub-saharan africa, u.s. geological survey, 2011 [2] awuah-offei, k., summers d., hirsch c. j., reducing energy consumption and carbon footprint through improved production practices, final technical report, missouri university of science and technology, 2010 [3] indonesia government, national inventory guidance manual book 1 volume 1 use and procurement of energy table 2.2 (2012) [4] indonesia government, national inventory guidance manual book 1 volume 1 use and procurement of energy table 2.3 (2012) [5] letter of emission factor (dj-esdm), 2012 title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper perception analysis of the user against the open green space in the campus area of sriwijaya university indralaya aries sandratama1*, dinar da putranto1, sarino1, ari siswanto1, 1 department of civil engineering, faculty of engineering, university of sriwijaya, palembang-prabumulih street km.32 indralaya, south sumatera, 30662, indonesia *corresponding author e-mail: aries_arch02@yahoo.co.id abstract sriwijaya university campus area, there is the built environment in the form of buildings and good natural environment, in the form of open green spaces are scattered throughout the campus of the sriwijaya university. empty land behind the campus planned to be used as open green space that supports the activity of civitas academia campus that includes professors and students. open green space in the campus, should ideally have a physical function among other things as a function of aesthetic, micro climate controller and shading place and provides the convenience of its users to have activity in the open green space. other green open spaces function as supporting educational activities, conservation, recreation and identity. the method used is the survey of the respondents against the respondents using quantitative and qualitative descriptive method. the purpose of the research is to analysis the perception of green open space for student and lecturer at faculty of agriculture of sriwijaya university indralaya. the numbers of respondents are 151 people. detailed questionnaire is divided into two characteristics; there are economic and social space requirements. the results of the socio-economic characteristics of the questionnaire are 29.14% of lecturer and student is 70.86%. questionnaire characteristics space requirements indicate that there are similarities in the educational activities come within the open green space at both the lecturer (50.00%) and students (47.66%) which is practical. keywords users perception, open green spaces received: 20 march 2018, accepted: 25 may 2018 https://doi.org/10.26554/ijems.2018.2.2.38-41 1. introduction sriwijaya university is a university in south sumatra province with a land area of approximately 700 ha is located 38 kilometers south of the city of palembang and is the centre of educational activities for undergraduate level who are doing development stage open green space. up to the year 2017 sriwijaya university campus continues to grow and already have 10 (ten) faculties: faculty of economics, faculty of law, faculty of medicine, the faculty of engineering, faculty of agriculture, faculty of teacher training and education, faculty of social and political sciences, faculty of sciences, faculty of computer science and the faculty of public health. sriwijaya university campus in the area besides the built environment in the form of buildings there is also a good natural environment in the form of open green spaces are scattered throughout the campus of the university of sriwijaya and vacant land behind the campus that would later serve as open green space that supports the activity of civitas academica campus that includes professors and students (mcfarland, 2008). open green space in the campus, should ideally have a physical function among other things as a function of aesthetic, micro climate controller and shading place and provides the convenience of its users to have activity in the open green space. other green open spaces function as supporting educational activities, conservation, recreation and identity. all functions of the open green space can be maximized, for it needs to be done further studies in planning the setup the shape of the pattern space needed and the structure of the green open space landscape using quantitative and qualitative methods of descriptive with direct interviews, literature review, �eld observation and documentation that can accommodate the needs of every departments in the faculty as well as be used as a complementary educational activities by all departments which exist as a learning space open. 2. experimental section 2.1 research location this research was conducted in the area of argo training center (atc) university of sriwijaya indralaya ogan ilir regency https://doi.org/10.26554/ijems.2018.2.2.38-41 sandratama et. al. indonesian journal of environmental management and sustainability, 2 (2018) 38-41 table 1. the number of samples of the faculty of agriculture no majors/programs of study lecturer students 1 agribusiness 9 27 2 agroecotechnology 2 10 3 agronomy 6 9 4 aquaculture/aquaculture 3 7 5 plant protection 3 2 6 soil science 5 11 7 farm 4 11 8 agricultural engineering 5 11 9 fishery product technology 3 8 10 agricultural technology 4 11 the number of sub total 44 107 the percentage of (%) 25 75 the total number of 151 table 2. characteristics of lecture respondents based on based on the type of educational activities in the area of open green space study program educational activities in the area of open green space total amountlab course farm nursery sports other: practice/discussion agribusiness 3 2 0 1 3 9 agroecotechnology 1 1 0 0 0 2 agronomy 4 2 0 0 0 6 aquaculture/aquaculture 1 0 2 0 0 3 plant protection 1 2 0 0 0 3 soil science 5 0 0 0 0 5 farm 4 0 0 0 0 4 agricultural engineering 2 2 0 1 0 5 fishery product technology 1 0 0 1 1 3 agricultural technology 0 2 0 1 1 4 the total number of 22 11 2 4 5 44 the percentage of (%) 50 25 4.55 9.09 11.36 100 figure 1. research location 2.2 methods of data collection data collection aims to collect data and information on the location of research. the techniques used to collect the data that corresponds to the object of the study are, as follows: 2.2.1 literature study method of data collection is done by looking for information related to open green space area of education university of sriwijaya indralaya sourced from books, articles in print or website-the o�cial website and the results of other studies supports setup of open green space area of the campus of the university of sriwijaya indralaya. questionnaire is done to the lecturer of the faculty of agriculture university of sriwijaya, and student representative faculty of agriculture in every department. interviews can be conducted using guided interview or none. © 2018 the authors. page 39 of 41 sandratama et. al. indonesian journal of environmental management and sustainability, 2 (2018) 38-41 table 3. characteristics of student respondents based on based on the type of educational activities in the area of open green space study program educational activities in the area of open green space total amountlab course farm nursery sports other: practice/discussion agribusiness 8 6 0 10 3 27 agroecotechnology 5 4 1 0 0 10 agronomy 4 3 0 2 0 9 aquaculture/aquaculture 7 0 0 0 0 7 plant protection 1 0 0 0 1 2 soil science 6 4 0 1 0 11 farm 5 1 1 4 0 11 agricultural engineering 4 1 0 4 2 11 fishery product technology 4 0 0 4 0 8 agricultural technology 7 1 0 2 1 11 the total number of 51 20 2 27 7 the percentage of (%) 47.66 18.69 1.87 25.23 6.54 2.2.2 field research the �eld survey carried out using some of the techniques of approach among others: 1. the techniques of observation, i.e. direct observations on the activities and behaviors, and students against lecture open green space in the university campus area of srivijaya indralaya. 2. engineering interview (interview techniques), performed by holding a question and answer to the professors, and students. deployment of the questionnaire is done to the lecturer of the faculty of agriculture university of sriwijaya, and student representative faculty of agriculture in every department. interviews can be conducted using guided interview or none. 3. field note techniques, that is a technique performed in obtaining data in the �eld by noting the overall things found good data about the informant/respondent as well as data about the state of the location of the examination as a condition of open green space in the area of university of sriwijaya indralaya. 2.3 method of sampling 2.3.1 number of population the population here was faculty and students of the university of sriwijaya indralaya. the number of population at the faculty of agriculture in each department with the calculation and distribution of population sampling as follows: lecturere= 172 ·100 697 =25%×172=43 (1) student = 525 ·100 697 =75%×172=131 (2) calculation of the sample in the agribusiness department of faculty lecturer of agriculture is lecturerof agribusiness= 36×100 172 =21samples (3) lecturerof agribusiness= 21×43 100 =9samples (4) 2.3.2 sample determination sampling techniques in the study using the determination of the total population of respondents used method strati�ed random sampling. the calculation of the amount of sample of lecturer and students that will be put to individual departments in the faculty of agriculture is shown in table 1. 3. results and discussion 3.1 qualitative analysis based on respondents data characteristics is necessary to know the behavior of users of open green space to development of open green space campus. based on the table above it can be concluded that the average educational activities performed in the area of open green space is practical/circling of 50%, 25% farm planting, at 11% asian, 9.09% and 4.55% sports utilized for breeding primary data collection was carried out for almost two weeks, on february 25 – march 8, 2018, with the use of a detailed questionnaire and interview survey method in location of the faculty of agriculture of these characteristics include 2 (two) aspects of characteristics, i.e. social characteristics of users and the characteristics of the space requirements at sriwijaya university, indralaya. in this case, the selected respondent was restricted in the faculty of agriculture university of sriwijaya indralaya i.e. © 2018 the authors. page 40 of 41 sandratama et. al. indonesian journal of environmental management and sustainability, 2 (2018) 38-41 table 4. recapitulation of the characteristics prospective users of open green space based on the respondent’s professors and students characteristic respondent lecturer (%) students (%) socio-economic characteristics the status of the 44 people (29,14) 107 people (70,86) places to stay palembang (68,18) indralaya (campus) dan indralaya (outside campus) (39,25) semester semester 8 (31,78) characteristics of space requirements motivation in the area of open green space circling/lab course (50,00) recreation (48,60) educational activities in the area of open green space lab course (50,00) lab course (47,66) the type of land that is suitable dry (72,73) moist (43,93) types of facilities and infrastructure in open green space open space (43,18) open space (30,84) time activities in open green space the morning (06-10) (50,00) the afternoon (15-18) (69,16) old activities at open green space 1-3 hours (72,73) 1-3 hours (62,62) the supporting infrastructure are in need in open green space a place of worship and seat (25,00) wifi (32,71) estimates of the frequency of visits once in a week and rarely (1-3 times a week) (38,64) quite often (3-6 times a week) (27,10) the characteristics of estimation number of people/students in open green space > 10 people (63,64) > 10 people (47,66) lecturers and students. from the results of a questionnaire, 151 distributions then obtained the number of respondents to the faculty of agriculture university of sriwijaya indralaya i.e. as much as 44 respondents lecturer 29.14% and 107% of student respondents 70.86. 3.2 quantitative analysis based on respondents as for the results of the analysis of the characteristics of the potential candidate users open green space will be covered in more detail in the following: 3.2.1 social characteristics of the user measurement of the characteristics of the user is based on social status, place of residence, and semester. 3.2.2 characteristics of space requirements measurement of the characteristics of space requirements based on the place of doing routines that most often, the primary motivation if it is in the area of green space, this type of educational activities in the area of open green space, the type of land that is suitable for your �eld, type land that is suitable for your �eld, timing of activities in open green space, old activities during the open green space, ancillary infrastructure do you need for activities in open green space, an estimate of the frequency of visits and how the estimated number of people/students in the conduct of activities in the open green space. the characteristic can be seen in table 2-4. based on the above table it can be seen that out of a total 100% or respondents there are as many as 107 47.66% or 51 (�fty-one) student respondents chose teaching, as for the majority of the respondents were students of soil science, and livestock. 4. conclusions the results of the socio-economic characteristics of the questionnaire for lecturer and student are 29.14% and 70.86%. characteristics of space requirements questionnaire indicates that there are similarities in the educational activities come within the open green space at both the lecturer (50.00%) and students (47.66%) that is practical. references mcfarland, a. (2008). relationship between student use of campus green spaces and perceptions of quality of life. texas state university, san marcos, tx. horticultura technology, 18; 196–319 © 2018 the authors. page 41 of 41 introduction experimental section research location methods of data collection literature study field research method of sampling number of population sample determination results and discussion qualitative analysis based on respondents quantitative analysis based on respondents social characteristics of the user characteristics of space requirements conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper identification of land adequacy for green open space development area of tanjung barangan on the condition of land properties in palembang linda utami1*, satria jaya priatna2, dadang hikmah purnama2, 1student of magister program of environmental management study program of sriwijaya university postgraduate program 2lecturers of magister program of environmental management study program of sriwijaya university postgraduate program, south sumatera, indonesia *corresponding author e-mail: lindautamirs@gmail.com abstract the city of palembang is one of the cities that experienced rapid development and became the center of human activity. so that the expansion of the city to the periphery causes green open space reduction. the reduction of green open space inflicted the disruption of the balance between nature and human systems. retention ponds include reduction of green open space border that serves as a drainage system so as to prevent flooding during the rainy season and maintain groundwater reserves during the dry season. this study aims to: 1) identify the existing condition of soil properties (physical and chemical) in the green open space development area of tanjung barangan retention pond in plan area that will be functioned as a retention pond of palembang city; 2) to see the relation between the physical and chemical of soil condition with the type of vegetation that will be developed in the area of green open space development plan. this research used descriptive normative method and sampling was done by sample purposive sampling. there were 4 (four) research sample points. green open space development area tanjung barangan in retention pond, based on analysis of soil condition and vegetation analysis based on permen pu no. 5 of 2008 there are 3 types of vegetation recommended, 4 types of vegetation that can be recommended and based on the existing condition there are 7 types of vegetation. keywords green open space, tanjung barangan retention pond, soil condition, vegetation recommended received: 26 june 2018, accepted: 4 august 2018 https://doi.org/10.26554/ijems.2018.3.2.94-97 1. introduction the city of palembang is one of which was marked by the development of city infrastructure in the form of renovating and building sport facilities, building hotels, malls, restaurants and light rail construction project or light rail transit (lrt) palembang, south sumatra. based on indonesian republic law number 26 of 2007 on spatial planning, every city and regency in indonesia should have green open space at least 30% of city area, which is 20% green open space built by the government for public interest and 10% of the green open space are private that the government requires to be created/owned by every home. the change of land will threaten the existence of green open space and cause a change of micro climate that is increasing the temperature of the air and the occurrence of natural phenomena such as urban heat island (uhi) and greenhouse effect and can damage soil functions i.e. as control of pollution and soil damage (waluyo, 2009). the objectives of this research were: 1) identify and evaluate the existing condition of soil properties (physical and chemical) in the green open space development plan area that will be functioned as a retention pond of palembang city; 2) to see the relation between the physical and chemical of soil condition with the type of vegetation that will be developed in the area of green open space development plan; 3) recommend the appropriate vegetation types to be developed in the green open space development plan, retention pond area in palembang city. 2. experimental section this research was conducted in may until august 2017, implemented in the administrative area of palembang city. sampling point are located in green open space development area of tanjung barangan retention pond in bukit baru village, ilir barat 1 sub-district of palembang city. the researcher chose the research location based on the regional regulation of palembang city no. 2 of 2013 on sustainable development, besides that location had typical characteristic and heterogeneity of the area. researchers in this study used descriptive survey method. soil sampling was done by integrated sample. the research parameters are: (1) physical soil (effective https://doi.org/10.26554/ijems.2018.3.2.94-97 utami et. al. indonesian journal of environmental management and sustainability, 3 (2018) 94-97 figure 1. research location sampling point at the green open space development plan area of tanjung barangan retention pond depth (soil driling), soil texture (sl-mu-tt-10, pipette), soil structure (observations), soil color (munsell soil color chart) and soil permeability (constant head permeameter)), (2) soil chemistry (ph (potensiometri), n (kjeldahl), p (bray i/ii), k (bray/olsen) and c-organic (welkley black/gravimetri)). the sample of the research was tested in the field and laboratory in accordance with the existing testing procedures. sampling method is done by sample survey method. the detail intentionally coordinate point was determined based on location extent. the map of soil sampling in the green open space development area of tanjung barangan retention pond can be seen in figure 1. 3. results and discussion 3.1 overview of research locations the green open space development area of tanjung barangan retention pond is adjacent to: north borders with sukarami and banyuasin districts; east bordering east ilir district i and bukit kecil; the south by the district ilir barat ii; and the west by gandus and regency of banyuasin [4]. green open space of tanjung barangan retention pond at coordinate point 2° 59’10,8 ”s and 104° 41’55,4” e is in the highest area of palembang city located in district ilir barat i with an altitude of about ± 10 meters above sea level and bumpy areas. based on the geological condition of palembang city for the western part of the territory, the stratigraphy of the territory is alluvial and swamp units (bps, 2014). 3.2 vegetation in the area of green open space development plan retention pond tanjung barangan palembang based on the results of laboratory analysis and direct observation in the field of research location at development plan area of green open space retention pond tanjung barangan, obtained the average value of physical and chemical parameters of soil can be seen in table 1. 3.3 recommendation of vegetation type for green open space of tanjung barangan retention pond based on the result of recapitulation of the average value of soil physical and chemical parameters at green open space in tanjung barangan retention pond in table 1 and vegetation recommendation from regulation of minister of public work no. 5 of 2008, the result of vegetation type analysis recommended for green open space of tanjung barangan retention pond can be seen in table ??. based on the table, it was known that there are 7 types of vegetation recommendations from regulation of minister of public works no. 5 of 2008, after analyzed based on land suitability and table 1. recapitulation of average value of physical parameters and soil chemistry no soil green open space development plan characteristis tanjung barangan retention pond soil physical parameters 1 effective depth moderate (60 cm >80 cm) 2 soil texture clayey loam, clay and loam 3 soil structure platy dan granular 4 soil color gray, yellowish brown to black 5 soil permeability medium to moderate soil permeability soil chemistry parameter 1 ph very acidic 2 n-total (nitrogen) low to medium 3 p2o5 available very low 4 k2o available very high 5 c-organic low to very high © 2018 the authors. page 95 of 97 utami et. al. indonesian journal of environmental management and sustainability, 3 (2018) 94-97 figure 2. recapitulation of analysis results of vegetation types recommended for green open space of tanjung barangan retention pond sr: there was conformity between result of laboratory analysis of physical and chemical factor of soil at research location with the analysis of vegetation type ; r: recommended with condition of land suitability >7 parameters ; br: can be recommended with land suitability requirement between 4-6 parameters and land management ; tr: not recommended with condition of land suitability <3 parameter of vegetation type laboratory analysis of soil physical and chemical factors, there are 3 (three) types of vegetation recommended for planting in the green open space of tanjung barangan retention pond and 4 types of vegetation that can be recommended to be planted on the green open space with the condition of land management for land suitability. the recommended vegetation types to be planted in the green open space of tanjung barangan retention pond are casuarinas (casuarina equisetifolia), coconut (cocos nucifera) and fern tree (filicium decipiens). the type of fern tree vegetation (filicium decipiens) has the best ability to intercept the rainwater. the existence of casuarinas vegetation (casuarina equisetifolia) at karang gadung beach, kebumen, shows positive impact to micro climate improvement that decreased the light intensity from 1925 lux to 213 lux, decreased air temperature from 31°c to 25°c and increased air humidity from 84% to 100% (harjadi, 2017) that the plant trembesi / ki rain (samanea saman) is a recommendation plant to be a green open space plant because the trembesi plant has a good ability to absorb co2 (martuti, 2013) and has a low evapotranspiration so it is suitable to be planted in green open space across upstream which functions as a water catchment (budiman, 2010) in addition, trembesi plants are intended for public spaces such as parks because this plant has a very wide canopy that is popular as a shade plant and has a strong absorbent groundwater capability (damayanti, 2016). while the type of coconut vegetation (cocos nucifera) as reinforcing vegetation in critical land (nahdi et al., 2014). based on direct observations of the existing conditions of vegetation types in the planned area of green space development, the tanjung barangan retention pond contained 7 (seven) types of vegetation, among others: gelam tree (melaleuca leucadendra), tanjung (mimosups elengi), nipah tree (nypa fruticans), leaves leaf (melastoma candidum), purun (lepironia articulata), lotus flower (nymphaea sp) and shrimp nails (stenochlaena palustris bedd). there is no type of vegetation that grows in the existing conditions in the green space of the tanjung barangan retention pond which is included in the vegetation type recommendation from the minister of public works regulation no. 5 of 2008. if seen from the location of the rth location the tanjung barangan retention pond is a type of swamp land so the vegetation dominating the area these are gelam trees (melaleuca leucadendra), nipah trees (nypa fruticans) and lotus flowers (nymphaea sp) (arsyad, 1989). that lotus flower (nymphaea sp) vegetation in environmental waste management can reduce bod in tofu industrial wastewater so that this vegetation is very good if it grows in the barangan peninsula region in retention ponds. 4. conclusions from the results of the research that has been done, it can be concluded that the green open space area of tanjung barangan retention pond has characteristics of physical and chemical factors of the soil, they are: the effective depth is moderate, textured clay loam, loam and clay, granular soil structure and platy, gray and yellowish brown, moderate and moderately rapid soil permeability, soil ph is very acidic, has a low to moderate n-total, p2o5 content is very low, k2o content is very high and has a © 2018 the authors. page 96 of 97 utami et. al. indonesian journal of environmental management and sustainability, 3 (2018) 94-97 low c-organic content up to very high. from 7 (seven) types of vegetation recommendation from the regulation of minister of public works no. 5 of 2008, after analyzed based on land suitability and laboratory analysis of soil physical and chemical factors, there are 3 (three) types of vegetation recommended and 4 (four) types of vegetation classified ass the category that can be recommended but with the condition that the soil treatment should be done to increase the soil ph level by calcification on green open space of tanjung barangan retention pond. references arsyad, s. (1989). konservasi tanah dan air. institut pertanian bogor press bps (2014). badan pusat statistik kota palembang dan bappeda kota palembang budiman, a. (2010). analisis manfaat ruang terbuka hijau untuk meningkatkan kualitas ekosistem kota bogor dengan menggunakan metode gis. master’s thesis, fakultas pertanian ipb, bogor. damayanti, e. (2016). tanaman penyelamat lingkungan. http://portal.bangkabaratkab.go.id/content/tanamanpenyelamat-lingkungan harjadi, b. (2017). peran cemara laut (casuarina equisetifolia) dalam perbaikan iklim mikro lahan pantai berpasir di kebumen. jurnal penelitian pengelolaan daerah aliran sungai, 1(2); 73–81 martuti, n. k. t. (2013). peranan tanaman terhadap pencemaran udara di jalan protokol kota semarang. jurnal biosantifika berkala ilmiah biologi, 5(1) nahdi, d. marsono, and a. m. b. tjut. s. djohan (2014). struktur komunitas tumbuhan dan faktor lingkungan di lahan kritis, imogiri yogyakarta. jurnal manusia dan lingkungan, 21(1); 67–74 waluyo, p. (2009). distribusi spasial suhu permukaan dan kecukupan ruang terbuka hijau di kota semarang. skripsi. depatemen konservasi sumberdaya hutan dan ekowisata. fakultas kehutanan institut pertanian bogor. © 2018 the authors. page 97 of 97 introduction experimental section results and discussion overview of research locations vegetation in the area of green open space development plan retention pond tanjung barangan palembang recommendation of vegetation type for green open space of tanjung barangan retention pond conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper analysis of the effect of the addition of fly ash and petrsoil on the soil shear strength of the swamp area indrayani 1*, andi herius1, daiyan saputra1, al muhammad fadil1 1civil engineering department, politeknik negeri sriwijaya, palembang, indonesia *corresponding author e-mail: iin indrayani@polsri.ac.id abstract the existence of irrigation canals greatly supports the production of rice produced, where irrigation channels will be equipped with embankment to protect irrigation channels. existing soil must certainly be able to withstand shear strength to withstand embankment, while the soil in the south sumatra region, especially the swamp area has a low shear power so it cannot hold back the shear strength from the embankment. for this reason, it is necessary to research the shear strength of the soil in the swamp area by adding fly ash and petrasoil in order to get the effect of increasing the value of the soil shear strength in the swamp area. a mixture of fly ash and petrasoil was chosen because the shear strength of the soil could be increased by the addition of fly ash, whereas petrasoil was used because in some road works using petrasoil to increase the carrying capacity of the soil. fly ash are used because in previous research with the addition of fly ash it will cause an increase in shear strength. the tests consists of the seive analysis, index properties, atterberg limits, soil compaction, and shear strength testing, based on sni and astm. mixed variations consist of 5, namely: (i) soil + petrasoil; (ii) soil + 10% fly ash + petrasoil; (iii) soil + 15% fly ash + petrasoil; (iv) soil + 20% fly ash + petrasoil; (v) soil + 20% fly ash; all variations without ripeningthe highest soil cohesion value is 20.21 kpa in the variation of the mixture of 10% fly ash + petrasoil, while the thighest shear angle value is 32.38o on the variation of the mixture of 20% fly ash + water. this means that the pozzolanic content of ash fly in the soil causes an increase in the value of cohesion and shear angle, while the use of petrasoil as a mixture must be with other additives. keywords shear strength, fly ash, petrasoil received: 20 february 2020, accepted: 13 march 2020 https://doi.org/10.26554/ijems.2020.4.1.10-13 1. introduction to support the rice granary program in indonesia the south sumatra provincial government and supported by the city and district governments continue to work on building irrigation channels that can irrigate existing rice fields, so that the water needs for farmers to irrigate the fields are fulfilled and to protect irrigation channels from flooding due to overflowing river water, a embankment was built. the main function of the dike construction is to protect the existing irrigation channels, therefore the strength and security of the dike must be well planned. one of the factors that must be considered in the planning of embankments with soil material is the condition of the existing soil stability, where soil conditions in swamp areas have low stability. embankments made from the soil will certainly easily experience landslide on the embankment slope due to natural conditions or human activities or other living things, so the stability of the slope is certainly very necessary in the planning of an embankment. many studies have been done to improve soil stability, including by wibawa (2015), the study resulted in an increase in the shear strength value of clay with the addition of gypsum waste. the other research conducted by indrayani et al. (2018), the research results show that there is an increase in the carrying capacity of the soil using fly ash. research related to increasing the carrying capacity of the soil and the shear value of the soil have also been carried out using other materials such as lime and petrasoil (herius et al., 2019; hakam et al., 2010; phanikumar, 2009; brooks, 2009). it was from this background that this research was carried out, ie by adding fly ash and petrasoil to the soil in the swampy area to increase the shear strength of the soil. because south sumatra has a lot of fly ash which is the remains of burning from coal so fly ash is used as addition material, while petrasoil is an added material in the form of powder https://doi.org/10.26554/ijems.2020.4.1.10-13 indrayani et. al. indonesian journal of environmental management and sustainability, 4 (2020) 10-13 which is often used in construction projects to increase the carrying capacity of the soil. the addition of these two materials is expected to increase the shear strength of the soil in the swamp area so that the embankments that are built can function well in protecting irrigation canals. 2. experimental section 2.1 location of study all tests in this study were conducted at the sriwijaya state polytechnic materials testing laboratory while soil sampling was carried out at one of the swampy locations in south sumatra province, namely in tanjung lago sub district, banyuasin regency. soil sampling locations can be seen in figure 1. figure 1. sampling location the fly ash added material used in this study was taken from the coal burning residue of pt. tanjung enim. 2.2 classification method the tests include sieve analysis using a vibrator machince and a glass hydrometer, index properties using a 50 ml picnometer tube, atterberg limit testing using a cassagrande bowl, compaction testing using a compactor, and shear strength testing using a shear test machine. atterberg limit testing and shear strength were carried out in 6 variations, namely: (i) soil + petrasoil; (ii) soil + 10% fly ash + petrasoil; (iii) soil + 15% fly ash + petrasoil; (iv) soil + 20% fly ash + petrasoil; (v) soil + 20% fly ash + water; (vi) normal soil. the ratio variation of petrasoil to water is 1 kg : 1000 liters. the fly ash does not get special treatment, but petrasoil is dissolved into water with a ratio of petrasoil to water is 1 kg: 1000 liters. all testing and analysis methods carried out refer to the astm and sni guidelines, both of which are standards issued in every test in a soil laboratory. 2.3 analysis method this research starts from: (i) soil sampling in swampy areas, (ii) specific gravity testing to get the soil classification to be tested, (iii) atterberg boundary testing to get the liquid limit and plastic limit of all variations of soil mixture, (iv) sieve analysis and hydrometer test to get soil roughness, the higher the soil roughness, the better the soil, (v) compaction testing to obtain optimal water content, where the optimal water content will be used to make soil shear strength test samples, and (vi) and (vi) testing the shear strength of the soil to get the effect of the addition of fly ash and petrasoil to the shear strength of the soil in the swampy area. 3. results and discussion 3.1 testing of the properties index property index testing includes specific gravity testing, sieve analysis and atterberg limits, where the samples in this test use native soil. from the result of specific gravity test obtained a soil specific gravity value of 2.60, while from the result of sieve analysis test results obtained by soil that passes the filter # 4 (4.75 mm) by 100% and soil that passes the filter # 200 (0.075 mm) by 79.98%. from the test results of atterberg limit was obtained liquid limit value of 63%, 43% plastic limit, and plasticity index 20%. from the results of property index testing was obtained the soil classification is of clay soil, which has a grain size between <0.002 mm to 2.00 mm. 3.2 compaction testing the compaction test was conducted in 6 conditions, namely (i) soil + petrasoil; (ii) soil + 10% fly ash + petrasoil; (iii) soil + 15% fly ash + petrasoil; (iv) soil + 20% fly ash + petrasoil; (v) soil + 20% fly ash + water; (vi) normal soil. compaction test was carried out to obtain the weight of the dry soil contents and the optimum water content percentage. the result of the compaction test can be seen on the tabel 1, while the optimum moisture content graph can be seen in figure 2 and the dry weight content graph can be seen in figure 3. figure 2. the optimum water content percentage (%) the graph in figure 2 shows that the highest optimum moisture content in the variation of the mixture of 10% fly ash + petrasoil, this means the effect of adding petrasoil causes an increase in water content. the higher the soil water content, the easier it is to compact the soil. the graph in figure 3 shows that the highest dry weight content of the soil is in the variation of the mixture of 20% fly ash + water. it can also be seen from the graph that the addition of petrasoil results in a decrease in the dry weight of the soil, this shows that petrasoil can result in a decrease © 2020 the authors. page 11 of 13 indrayani et. al. indonesian journal of environmental management and sustainability, 4 (2020) 10-13 table 1. test results and analysis of compaction test no variation the optimum the weight of the soil dry water content (%) contents (gd max) (gr/cm3) 1 soil + water (s+w) 15.76 1.286 2 soil + petrasoil (s+p) 20.01 1.264 3 soil + 20% fly ash + water (s+20fa+w) 17.57 1.65 4 soil + 10% fly ash + petrasoil (s+10fa+p) 25,03 1.193 5 soil + 15% fly ash + petrasoil (s+15fa+p) 22,03 1.178 6 soil + 20% fly ash + petrasoil (s+20fa+p) 24.28 1.182 table 2. test results and analysis of shear strength no variation cohesion value (c) shear angle ∅) (kpa) (°) 1 soil + water (s+w) 18.35 16.45 2 soil + petrasoil (s+p) 8.5 20.16 3 soil + 20% fly ash + water (s+20fa+w) 6.85 32.38 4 soil + 10% fly ash + petrasoil (s+10fa+p) 20.21 19.02 5 soil + 15% fly ash + petrasoil (s+15fa+p) 12.5 24.34 6 soil + 20% fly ash + petrasoil (s+20fa+p) 8.2 27.83 figure 3. the weight of the soil dry contents in the dry weight of the soil, where the lower the dry weight of the contents, the greater pore space in the soil causing the soil to become less dense. 3.3 shear strength test results soil shear strength testing is done in 6 variations as in compaction testing. for the value of cohesion normal soil was taken from the results of research conducted by polii et al. (2018), that is 25.219 kpa. the results of the soil shear strength test can be seen in table 2, while the graph of cohesion value can be seen in figure 4 and the graph of shear angle values can be seen in figure 5. from figure 4 it can be seen that there is the highest cohesion value on the variation of the mixture of 10% fly ash + petrasoil, this shows that the addition of 10% fly ash + petrasoil increases the soil cohesion value. increased cohesion value will increase the value of the soil shear strength due to the attachment between soil particles that are getting stronger. pozzolan in the fly ash can bind to the soil partifigure 4. cohesion value (c) figure 5. shear angle value (°) cles that exist, so that the bond with soil particles increases. the addition of petrasoil can increase bonds between soil particles, but the more fly ash is mixed, the ability of petrasoil to bind soil particles and fly ash is lower. this can be seen in the graph that the higher the addition of fly ash will cause a decrease in the value of cohesion in the soil. from figure 5, it can be seen that the highest shear angle value on the mixture variation 20% fly ash + water, where the higher the angle of shear, the greater the contact area so that the ability to withstand the shear also increases. © 2020 the authors. page 12 of 13 indrayani et. al. indonesian journal of environmental management and sustainability, 4 (2020) 10-13 pozzolan content in fly ash can increase the density of the soil, this causes an increase in the shear angle of the soil. from the shear strength test results on variations in the addition of petrasoil without fly ash shows that there is a decrease in the value of cohesion and shear angle values, this shows that the addition of petrasoil without other added ingredients can reduce the value of shear strength, this statement is reinforced from the results of research conducted by herius et al. (2019), which states that the addition of petrasoil without other additives can reduce the value of the carrying capacity of the soil, for that in construction projects that use petrasoil as added material must mix it with other added ingredients. until now there has not been obtained a definite reference about content of petrasoil, but petrasoil has been used in several construction projects. for this reason, further research needs to be done on the content in petrasoil so that it is not wrong in its use in construction works. 4. conclusions the highest soil cohesion value is 20.21 kpa in the variation of the mixture of 10% fly ash + petrasoil, while the highest shear angle value is 32.38° on the variation of the mixture of 20% fly ash + water. the addition of fly ash to the soil causes an increase in the value of cohesion and shear angle, while the petrasoil used as a mixture in the soil cannot be used without the help of other added ingredients. 5. acknowledgement acknowledgements for politeknik negeri sriwijaya, palembang, indonesia. references brooks, r. m. (2009). soil stabilization with fly ash and rice husk ash. international journal of research and reviews in applied sciences, 1(3); 209–217 hakam, a., r. yuliet, and r. donal (2010). studi pengaruh penambahan tanah lempung pada tanah pasir pantai terhadap kekuatan geser tanah. jurnal rekayasa sipil (jrs-unand), 6(1); 11–22 herius, a., i. i. indrayani, a. hasan, and a. mirza (2019). addition effect of petrasoil additive material on cbr value of soil in swamp areas. indonesian journal of environmental management and sustainability, 3(2); 67– 70 indrayani, i., a. herius, a. hasan, and a. mirza (2018). comparison analysis of cbr value enhancement of soil type in swamp area by addition of fly ash. science and technology indonesia, 3(2); 73–76 phanikumar, b. (2009). effect of lime and fly ash on swell, consolidation and shear strength characteristics of expansive clays: a comparative study. geomechanics and geoengineering: an international journal, 4(2); 175–181 polii, s. n., o. sompie, and l. d. manaroinsong (2018). pengaruh penambahan abu batu bara terhadap kuat geser tanah lempung. tekno, 16(69) pratama, a. w., i. iswan, and m. jafri (2015). korelasi kuat tekan dengan kuat geser pada tanah lempung yang didistribusi dengan variasi campuran pasir. jurnal rekayasa sipil dan desain, 3(1); 157–170 sni (1990). sni 03-1964-1990: testing methods about specific gravity wibawa, a. and e. s. hisyam (2015). pengaruh penambahan limbah gypsum terhadap nilai kuat geser tanah lempung. in fropil (forum profesional teknik sipil), volume 3. pages 65–71 © 2020 the authors. page 13 of 13 introduction experimental section location of study classification method analysis method results and discussion testing of the properties index compaction testing shear strength test results conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper effectiveness of spirulina platensis extract on wound area and tnf-α levels on blood: experimental studies in wistar rats made artificially by vulnus scissum and infected by staphylococcus aureus olvaria misfa1*, renni yuniati2, yan wisnu prajoko3 1biomedical sciences department, faculty of medicine, diponegoro university, semarang, indonesia 2dematovenerology department, faculty of medicine, diponegoro university, semarang, indonesia 3surgery department, faculty of medicine, diponegoro university, semarang, indonesia *corresponding author e-mail: olvaria.misfa@univrab.ac.id abstract this research uses randomized post-test only control group design. thirty-two (32) male wistar rats with incised skin and infected with s. aureus divided into 4 groups, namely the group given s.platensis extract at a dose of 500 mg / kgbb / day (x1) and a dose of 750 mg / kgbb / day (x2 ), the negative control group was given saline solution (c1), and the positive control group was given amoxicillin 150 mg / kg orally (c2). wound area measurements were taken on day 14 and serum tnf-α levels were examined on day 14 using the elisa method. data analysis was performed with one way anova test and continued with post hoc test lsd. the results showed mean size of wound closure on the 14th day in groups x1, x2, c1 and c2 is 8095.74; 6270.98;15502.69; 11475.20 micrometer with p <0.001. the mean tnf-α serum levels in the 14th day of x1, x2, c1, and c2 groups were 270.75; 222.83; 1730.33; 385.75pg / ml with p < 0.001. post hoc test of wound area showed significant differences between groups. post hoc test tnf-α levels showed significant differences between treatment groups x1 and x2 with group c1. spirulina platensis extract 500mg / kgbb / day and 750 mg /kgbb/ day have the smallest wound area significantly and reduce tnf-α levels on blood. keywords spirulina platensis, antibacterial, anti-inflammatory, tnf-α received: 5 june 2020, accepted: 19 june 2020 https://doi.org/10.26554/ijems.2020.4.2.551. introduction wounds are damage to the continuity of the skin, mucosa, and bones or other body organs caused by physical or thermal contact. wounds that arise will cause damage to the surface so it will no longer protect the structure underneath. infection of the wound can occur if it’s contaminated by microorganisms, like bacteria and can be a port de systemic entry infection. bacteria that often infect wounds are staphylococcus aureus (widiyani et al., 2016; guo and dipietro, 2010; dwivedi et al., 2017). the wound healing process is complex, beginning with the response to injury to restore the function and integrity of the damaged tissue (pawar et al., 2013). this process consists of the stages of inflammation, proliferation, and remodeling. wound healing can be hampered by local and systemic factors. the contaminated wound by bacteria affected to inflammatory cytokines, such as tnf-α (guo and dipietro, 2010). to accelerate wound healing with bacterial infection requires antibacterial administration (dwivedi et al., 2017; agra et al., 2013) in addition to the use of antibiotics. currently, the use of natural or herbal ingredients as an antibacterial is widely used as an alternative therapy. several studies of plant extracts have been proven to have an antibacterial effect and accelerate the healing process of wound infections in mice including the leaves of bangkong (pongamiapinnata), red betel leaf (piper crocatum ruiz & pav), bowdichia virgilioide, sida cordifolia, and ficus benghalensis (widiyani et al., 2016; dwivedi et al., 2017; pawar et al., 2013; agra et al., 2013) some micro strains blue algae have extracellular and intracellular metabolites with various biological activities, including anti-inflammatory and other antibacterial activities (usharani et al., 2015). one of the microalgae that have this potential is spirulina sp. spirulina platensis is micro-blue green algae, filamentous cyanobacteria with many bioactive compounds namely proteins, lipids, carbohydrate, and minerals (zinc, magnesium, manganese, selenium), pigments https://doi.org/10.26554/ijems.2020.4.2.55misfa et. al. indonesian journal of environmental management and sustainability, 4 (2020) 55(phycocyanin, β-carotene), riboflavin, tocopheroldanasam α-linoleate. (widiyani et al., 2016; guo and dipietro, 2010) several studies in india have shown the antibacterial effect of spirulina plantesis. according to usharani et al, spirulina platensis extract inhibits growth in gram-positive bacteria (streptococcus pyogenes, staphylococcus aureus, staphylococcus epidermidis, and bacillus cereus ); and gramnegative bacteria (proteus mirabilis, klebsiella pneumoniae, shigella flexneri, and salmonella typhi ) (usharani et al., 2015). chakraborty et al. (2010) showed that the water extract of s. platensis gave inhibitory zone results with the largest diameter in the culture of staphylococcus aureus. bioactive metabolite compounds that are contained by spirulina platensis that grow on the karimun jawa beach are also expected to play an antibacterial and anti-inflammatory role. 2. experimental section 2.1 spirulina platensis extract the extract used in this study was s. platensis powder us fda registration number 15594742028 and ceres number 50oga1200043 (9241). s. platensis powder was macerated in 95% ethanol solution with a concentration of 1:10 (one part of s.platensis powder macerated in 10 parts ethanol 95% solution). the maceration process is carried out for five days in a glass container. then stirred every day to ensure uniformity of the maceration process. after five days, the solution was filtered with whatman grade 1 filter paper and evaporated using a rotary evaporator at ethanol boiling point until a thick extract was obtained. this s. platensis extract was used as an ingredient in further tests, which are explained further below. 2.2 animal used in experiment thirty-two male wistar rats aged 2-3 months with a bodyweight of 100-200 grams were acclimatized for 7 days. the experimental animals were randomly divided into 4 groups and incised along 2 cm with a depth of 0.25 cm and infected by s. aureus bacteria. group i was given spirulina platensis extract orally at a dose of 500 mg / kgbw. treatment for group ii was 750 mg / kgbw for 14 days, and the negative control group was given 0.9% saline solution, and the positive control group was given amoxicillin 150 mg / kg orally. 2.3 incision procedure the rat was anesthetized with 0.1 cc of ketamine, then the back of the rat was shaved 3 cm x 2.5 cm and made an incision using a 2 cm long scalpel and a depth of 0.25 cm. a scalpel was held using the handle on the right hand by forming an angle of 30 − 40o with skin. the incision is made by pulling the scalpel towards the caudal. wounds are infected with s. aureus bacteria, then allowed to stand for 36-48 hours until infection occurs. 2.4 serum levels of tnf-α serum levels of tnf-α were taken from rat retroorbital blood vesselson the 14th day and the regulated by the elisa method. in this study using the rat tnf-α elisa kit (catalog no. e-el-r0019: elab science biotechnology, texas, usa) 2.5 analysis data the wound area 14-day was measured by imageraster software 3. the test used in this study is the one way anova test to see differences in wound area and tnf-α levels in the four treatment groups. the magnitude of the difference in wound area and tnf-α levels in each group were further analyzed using the post hoc lsd test. the significance value in this study is if the analyzed variable has a p-value <0.05. all statistical analyzes were carried out using the spss 25 program. 3. results and discussion all samples used had an average body weight almost the same between groups until the 14th day (table 1). mice lived until the end of the study and terminated at the end of the study. the analysis showed significant differences in wound area between the negative control group and the treatment group who were given spirulina platensis extract at a dose of 500 mg / kgbb / day and a dose of 750 mg / kgbb / day (as table 2). a significant difference was also shown between the positive control group and the group given spirulina platensis extract at a dose of 500 mg / kgbb / day, a dose of 750 mg / kgbb / day, and the negative control group. the analysis test showed a significant difference in tnfα levels between the negative control group and the treatment group that was given s. platensis extract at a dose of 500 mg / kgbb / day and a dose of 750 mg / kgbb / day. however, there was no significant difference between the positive control group and the treatment group who were given s. platensis extract at a dose of 500 mg / kgbb / day and a dose of 750 mg / kgbb / day. the wound healing process is a complex process consisting of the stages of inflammation, proliferation, and remodeling. bacterial contamination of the wound can cause prolongation of the inflammatory phase. one of the bacteria that often contaminates wounds is staphylococcus aureus. in this study, it was shown that spirulina platensis extract that given to mice which made an incision and was infected by s. aureus could accelerate wound closure seen from the wound area of each study group. the smallest area of wound is the group who were given spirulina platensis extract at a dose of 750 mg / kgbb / day on the 14th day. s. aureus infection in wounds can affect wound healing.(guo and dipietro, 2010) treatment of s. aureus infection depends on the type of disease and the presence or absence of drug-resistant strains (taylor and unakal, 2019). in addition to treatment with antibiotics, phytotherapy is © 2020 the authors. page 56 of 58 misfa et. al. indonesian journal of environmental management and sustainability, 4 (2020) 55table 1. wound area (micrometer) day 14 group the mean sd value of p negative control 15502.69 1406.07 p <0.001 positive control 11475.2 1395.73 s.platensis extract 8095.74 346.97 500 mg/kg bodyweight/day s.platensis extract 6270.98 1229.47 750 mg/kg bodyweight/day table 2. serum levels of tnf-α for day 14 treatment group the mean sd value of p negative control 1730.33 344.82 p <0.001 positive control 385.75 236.17 s.platensis extract 270.75 121.91 500 mg/kg bodyweight/day s.platensis extract 222.83 115.94 750 mg/kg bodyweight/day also a treatment option that has been widely used, one of which is by using s. platensis. compounds that act as antibacterial in s.platensis include phenols, flavonoids, and saponins. phenol activity will kill bacteria by damaging the permeability of bacterial cell walls. flavonoids will interfere with bacterial growth, eventually killing bacteria with form extracellular protein complexes and dissolved proteins on the cell wall. while saponin compounds will damage the cytoplasmic membrane of bacteria (vonshak, 1997; chakraborty et al., 2010; quader et al., 2013). usharani et al and biswajit et al has been reported that spirulina platensis extract has an antibacterial effect against s. aureus bacteria (usharani et al., 2015; chakraborty et al., 2010). in addition, pauzi et al’s research also shows that s. platensis extract wound healing activity and potential as a therapy for chronic wounds. spirulina platensis has compounds that act as antibacterial, including phenols, flavonoids, and saponins. in bacterial contamination, wounds can occur prolongation of the inflammatory phase due to endotoxins from bacteria that cause an increase in proinflammatory cytokines, one of which tnf-α (widiyani et al., 2016). staphylococcus aureus bacteria is one of the agents that can contaminate the wound. this study shows that there is a decrease in serum levels on tnf-α which given spirulina platensis extract to mice made an incision and was infected by s. aureus on the 14th day. the lowest decreased serum levels of tnf-α founded in the group that given s. platensis extract dose of 750 mg / kg / day. previous studies conducted by syeda et al showed that the extract s. platensisa dose of 500 mg / kg / day has an anti-inflammatory effect on acute and chronic inflammation. besides, studies in diabetic-induced mice by fariba et al. showed that extracts of s. platensis in doses of 20 and 30 mg / kgbb reduced levels of tnf-α, il-6, asl, alt, glucose, lipid parameters, andmalondialdehyde. (koru, 2012) in the process of wound healing, the release of proinflammatory cytokines, including tnf-α, il-6, and il-1, plays an essential role in the inflammatory phase. (syarina et al., 2015) the inflammatory phase will prolong when the wound is contaminated by bacteria. prolongation of the inflammatory period occurs due to the release of endoctocin which causes an increase in proinflammatory cytokines, one of them is tnf-α. if the increase in proinflammatory cytokines continues, the wound will become chronic and fail to heal. phycocyanin compounds and β-carotene is a phytochemical that acts as an anti-inflammatory in s. platensis. phycocyanin will inhibit the formation of tnf-α by suppressing expression cyclooxygeanase-2 (cox-2). while β-carotene will inhibit prostaglandins and nitric oxide which will suppress expression inos, cox-2, tnf-α and il1β (swain et al., 2017). s. platensis extracts have an anti-inflammatory effect. however, it does not show significant differences with the control group based on the average serum levels of tnfα on the 14th day. an increase in s. platensis extract dose is expected to reduce serum levels of tnf-α significantly when compared to the positive control group. 4. conclusions spirulina platensis extract in a dose of 500 mg / kg / day and 750 mg / kg / day had the smallest wound area significantly compared to the group given physiological solutions and © 2020 the authors. page 57 of 58 misfa et. al. indonesian journal of environmental management and sustainability, 4 (2020) 55those given oral antibiotics. whereas s. platensis extract dose of 500 mg / kgbb / day and dose of 750 mg / kgbb / day had significantly decreased blood serum levels of tnfα compared with the group given physiological solution. however, there was no significant difference in the reduction in blood serum levels of tnf-α between the groups presented a dose of 500 mg / kgbb / day and a dose of 750 mg / kgbb / day with positive control. references agra, i. k., l. l. pires, p. s. carvalho, e. a. silva-filho, s. smaniotto, and e. barreto (2013). evaluation of wound healing and antimicrobial properties of aqueous extract from bowdichia virgilioides stem barks in mice. anais da academia brasileira de ciências, 85(3); 945–954 chakraborty, b., r. p. jayaswal, and p. p. pankaj (2010). evaluation of antibacterial activity of spirulina platensis extracts against opportunistic pathogen model. drugs, 8(9); 2435–2465 dwivedi, d., m. dwivedi, s. malviya, and v. singh (2017). evaluation of wound healing, anti-microbial and antioxidant potential of pongamia pinnata in wistar rats. journal of traditional and complementary medicine, 7(1); 79–85 guo, s. a. and l. a. dipietro (2010). factors affecting wound healing. journal of dental research, 89(3); 219–229 koru, e. (2012). earth food spirulina (arthrospira): production and quality standarts. food additive; 191–202 pawar, r. s., p. k. chaurasiya, h. rajak, p. k. singour, f. a. toppo, and a. jain (2013). wound healing activity of sida cordifolia linn. in rats. indian journal of pharmacology, 45(5); 474 quader, s. h., s. u. islam, a. saifullah, m. f. u. majumder, and j. hannan (2013). in-vivo studies of the antiinflammatory effects of spirulina platensis. the pharma innovation, 2(4) swain, s. s., s. k. paidesetty, and r. n. padhy (2017). antibacterial, antifungal and antimycobacterial compounds from cyanobacteria. biomedicine & pharmacotherapy, 90; 760–776 syarina, p. n. a., g. karthivashan, f. abas, p. arulselvan, and s. fakurazi (2015). wound healing potential of spirulina platensis extracts on human dermal fibroblast cells. excli journal, 14; 385 taylor, t. a. and c. g. unakal (2019). staphylococcus aureus. in statpearls [internet]. statpearls publishing usharani, g., g. srinivasan, s. sivasakthi, and p. saranraj (2015). antimicrobial activity of spirulina platensis solvent extracts against pathogenic bacteria and fungi. advances in biological research, 9(5); 292–298 vonshak, a. (1997). spirulina platensis arthrospira: physiology, cell-biology and biotechnology. crc press widiyani, a., h. maheswari, and m. effendi (2016). effect of red betel leaf extract (piper crocatum ruiz & pav) against healing of incision wounds infected by staphylococcus aureus in male spraque-dawley rats. fmipaunpak © 2020 the authors. page 58 of 58 introduction experimental section spirulina platensis extract animal used in experiment incision procedure serum levels of tnf analysis data results and discussion conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper hotspot distribution analysis in east kalimantan province 2017-2019 to support forest and land fires mitigation nurwita mustika sari 1,2*, nurina rachmita 1, masita dwi mandini manessa1, 1department of geography, faculty of mathematics and natural science, universitas indonesia 2remote sensing applications center, lapan *corresponding author e-mail: nurwita.mustika@lapan.go.id abstract forest and land fires that have occurred in the territory of east kalimantan province have caused immediate disaster to the area from year to year and become a global concern in recent years. hotspots that potentially cause forest and land fires can be detected using satellites such as noaa-20. the purposes of this study are to analyze the distribution pattern of hotspots in east kalimantan province during 2017-2019, identify areas with the highest risk of fires caused by the high intensity of hotspot. the method used in this study is the nearest neighbor analysis and kernel density estimation analysis. the results showed that the distribution pattern of hotspots in east kalimantan province during 2017-2019 was clustered with the highest intensity of hotspots were in berau, east kutai and kutai kartanegara districts. and from the result of the analysis, the highest number of days has a peak hotspots on september each year. keywords forest and land fires, hotspots, nearest neighbor, kernel density estimation received: 3 march 2020, accepted: 24 march 2020 https://doi.org/10.26554/ijems.2020.4.1.28-33 1. introduction forest and land fires in several locations in indonesia such as kalimantan and sumatra occur almost every year with larger areas and longer duration. the impact of this forest and land fires physically is a decrease in air quality due to thick haze, followed by the risk of respiratory diseases such as ispa (acute respiratory infection). furthermore, on a global scale, the haze caused by forest and land fires, since the late 1990’s, the impact was felt to reach malaysia, singapore and brunei darussalam (rasyid, 2014). the movement of warm air masses and the effect on the weather around the fire area will trigger the spread of fire areas, especially during periods of active fires that require special attention (hayasaka et al., 2019). various kinds of losses caused by forest and land fires encourage all parties to make control effort so that similar incident will not recur, including suppressing the causes of forest and land fires from human factors (tacconi, 2016). a hotspot is a point in an area that is detected to have a higher temperature than the surrounding area that has the potential to cause forest and land fires (permenhut number p.12 / menhut-ii / 2009) . this hotspot can be identified in several ways including using noaa or modis terra and aqua satellites. detection of hotspots by other methods is the extended fuzzy c-means (efcm) method for large and very large data groups (martino et al., 2018) and the use of the extended fuzzy c-means spatiotemporal algorithm (martino and sessa, 2018). although every hotspot that is detected is not necessarily a fire, with a high level of confidence above 80%, this hotspot will help to identify the initial occurrence of forest and land fires so that it can help disrupt this disaster in the field (endrawati, 2016). previous studies have shown that hotspot data extracted from modis have the reliability to show areas that are actually burning (hantson et al., 2013), however the user needs specifications continue to increase to how hotspots can inform carbon emission (mouillot et al., 2014). in this study, the analysis of the hotspots distribution will be conducted, where the purpose of this study was to determine the hotspot distribution patterns in the area of east kalimantan province during 2017-2019, identify areas with high risk of fire due to high intensity of hotspots and identify periods with the most hotspots. previous research has been conducted to determine the pattern of point distribution including the analysis of the distribution of dengue disease points using the nearest neighbor method and identify risk areas with kernel density estimation (santosa et al., 2018), analysis of distribution pattern of common crime and robhttps://doi.org/10.26554/ijems.2020.4.1.28-33 sari et. al. indonesian journal of environmental management and sustainability, 4 (2020) 28-33 bery points (chen et al., 2010, 2012), for the health sector there were a spatial analysis of cancer cases (shah et al., 2014), spatial analysis of diarrhea cases (chaikaew et al., 2009), for the veterinary study (ward, 2007). kernel density method has also been used to determine the tendency of data intensity with the form of data points in the school reference case (adhi et al., 2019). meanwhile for hotspot cases, hotspot distribution has been analyzed using the kulldorff’s scan statistics (kss) method for peatland (kirana et al., 2016) and hotspot analysis with density-based spatial clustering algorithms with noise (dbscan) (usman et al., 2015). meanwhile the correlation between hotspot and rainfall has been done by (prayoga et al., 2017) with the result of sufficient correlation and negative relationship. for the distribution of hotspots, a spatial analysis was conducted for the malaysian peninsula (mahmud, 2017). however, the analysis of hotspot distribution patterns has not been conducted using the nearest neighbor analysis method for the specific area of east kalimantan province in the period of 2017-2019. meanwhile, to find out the period with the most number of hotspots, analysis was conducted to the hotspot data obtained from weather satellites, which are known to be the time span with the highest number of hotspots in an area (zubaidah and arief, 2004). the same thing was done in this study at east kalimantan province as one of the provinces with the largest forest and land fires, even for the area of fire including ranks third in indonesia (endrawati, 2016), it is important to analyze the hotspots in this area so that disaster management planning and implementation in the field can be more effective. figure 1. study area of hotspot distribution analysis figure 2. flowchart of hotspot distribution analysis 2. experimental section 2.1 material the data used in this study are hotspot data obtained from noaa-20 satellites since 2017-2019. other data used is the administrative boundary data of east kalimantan province obtained from badan informasi geospasial (big). the study area is presented in figure 1. east kalimantan province consists of 10 district / city including the district of berau, balikpapan, kota bontang, kota samarinda, kutai kartanegara, kutai barat, kutai timur, paser, penajam paser utara, mahakam ulu. another data is settlement data in the study area obtained from big in 2015. 2.2 method the analysis of the distribution pattern of hostspot points in the study area was carried out using the nearest neighbor analysis and kernel density estimation methods and is presented in figure 2. the stages of the research are: • pre-processing hotspot data data pre-processing was carried out by extracting hotspot data from noaa-20 satellites in the range of 2017 to 2019 using google earth engine. next step was selecting hotspot data for the study area, namely east kalimantan province. in processing hotspot data generated from noaa-20 satellite data, the area of mahakam ulu regency was included in the boundary of kutai barat regency which was located next to mahakam ulu, because the administrative boundary used was the year before the regional expansion. however, the number of hotspots in mahakam ulu was still included in the analysis. data raster that has been obtained was then converted to the format of © 2020 the authors. page 29 of 33 sari et. al. indonesian journal of environmental management and sustainability, 4 (2020) 28-33 the vector points, after that the data with the new format of vector points were merged into single data east kalimantan province hotspots 2017-2019. this data was used for the next stage namely statistical analysis. • statistical analysis method analysis of the data using nearest neighbor analysis, an analysis that was used as one of the ways to explain the distribution pattern of the hotspots by using calculation which considered the number of points, total area and distance. the final result of this analysis is an index (rn), the index value of nna distribution. he formula: dobs = σd n (1) rn = 2dobs √ n a (2) where, rn = nearest neighbour index; dobs = the average distance between the closest points; d = distance between the closest points; n = total points; a = width criteria : analysis of kernel density using interpolation of points distribution with the grid based distribution of hotspot to estimate the intensity through the calculation of the amount which is detected in a specific area. the hotspots in east kalimantan region were analyzed by kernel density analysis. for a random set of data with variables x1, x2, x ..., xn, the estimated kernel density to see the density probability is: f̂h(x) = 1 nh n∑ i=1 k( x − xi h ) (3) where, k is a kernel function and has several types, but the most commonly used is the normal function , k = 0.399 exp (-0.5u 2 ) (chen et al., 2010). 3. results and discussion program codes that were runned on the google earth engine obtained results in the form of raster format containing hotspots and a csv format file. the data in raster format subsequently converted into vector point format. the result is hotspots distribution in east kalimantan province with figure 3. distribution of hotspots in east kalimantan 2017-2019 time span of three years from 2017 to 2019. it can be seen in figure 3, the hotspots spread in all districts/ cities. nearest neighbor analysis (nna) summary result shows the pattern distribution of hotspot in east kalimantan with the nna indexes as shown in figure 4. figure 4. nnr values in the arcgis application nearest neighbor ratio or nnr is 0.674414 and the zscore is -5,77. with the provision of criteria which has been described previously, it can be interpreted that the hotspot pattern in the region of east kalimantan is clustered. analysis using kernel density estimation was carried out to find out how the intensity of the distributed hotspots and represented in the form of .tif raster data format. the result of raster data was then overlayed with administrative boundary as shown in figure 5. from the result of the kernel density estimation, it can be seen that the areas that were detected with the highest © 2020 the authors. page 30 of 33 sari et. al. indonesian journal of environmental management and sustainability, 4 (2020) 28-33 figure 5. kernel density analysis results number of hotspots have value of the highest rank namely 5. from the legend, it is showed that areas with the highest intensity of hotspots have the darkest color, while the areas of the rarest hotspots have the lowest value namely 1 and have brightest color. it can be interpreted that the most intensity of the hotspots in an area, then the color will be more intensive. the next result is the overlay between settlement and hotspots map. from the picture below it can be seen that the settlement residents quite close to the hotspots, of course, the incidence gives the effect of which is detrimental to the citizens, especially the thick haze problem arising from the forest and land fire event. the impact of the incident is such, the worse quality of air even up to the level of danger and decrease the visibility. another that, it caused the eye wound and acute respiratory infection (ispa). based on the map of the ministry of the environment life and forestry in 2019 (figure 7) , the use of land in the region of east kalimantan, consists of regional asylum nature/ conservation of nature, conservation of water, protected forest, limited production forest, permanent production forest, production forest that can be converted and other land uses (settlement, rice field, swamp, field, etcetera). hotspots in east kalimantan most substantial occurs in the protected forest, limited production forest and permanent production forest. analysis of the number of days indicated the existence of a hotspots. from the output csv file, it can be obtained the number of days with the number of hotspots in every month during the last 3 years (table 8). the region, which has the figure 6. overlay settlements with hotspots most number of days of hotspots in 2017 and 2019 is berau, and for 2018 is kutai kartanegara. areas with number of hotspots are berau, kutai timur and kutai kartanegara. from the following table it can be concluded that the highest number of days with the peak period of hotspots were in august and september in every year. based on these figures (figure 9-11), it can be seen that the number of days at the beginning of the year is still at a low level. the emergence of hotspots began to show an increase in july to reach the peak in september. this is considered to be related to the dry season which reaches its peak in august or september, causing the observed hotspots to reach their maximum. furthermore, in the following month namely in october the number of hotspots has decreased due to climatic conditions began to enter the rainy season again. this pattern is repeated every year. besides this, the emergence of high hotspots in august related to the agricultural activities of the community of kalimantan. the agricultural system that is usually applied in the kalimantan region is an extensive farming system, including the use of land prepared by burning of rice plants. rice plants are usually done before the rainy season around september, while land preparation is done one month before, namely in august. the land preparation activity can trigger the emergence of hotspots as an indication of forest / land burning activities. © 2020 the authors. page 31 of 33 sari et. al. indonesian journal of environmental management and sustainability, 4 (2020) 28-33 figure 7. land use in east kalimantan province 2019 4. conclusions based on the hotspot data processing of the east kalimantan province in 2017 2019, it is indicated that there were highest hotspots in berau, kutai timur and kutai kartanegara. from the result of the analysis using the nearest neighbor analysis (nna), the distribution of hotspots in east kalimantan province was clustered. while the result of the highest number of hotspots days, the peak was in of september in each year. pattern of hot spots and related with the rainy season could be a recommendation in preparing the disaster management strategy of forest and land fires in indonesia. preparations for the thick haze and smoke disaster management due to forest and land fires such weather modification technology is better prepared before the dry condition reaches the peak. 5. acknowledgement the authors would like to express our gratitude to the indonesia endowment fund for education (lpdp kementerian keuangan republik indonesia) for supporting this research fund. references adhi, b., n. santoso, and f. papilaya (2019). model design for analyzing prospective student data by using optimized figure 8. table number of hotspots days figure 9. charts in 2017 hotspot analysis and kernel density case study: swcu fti. proceedings of the 2019 geotic national seminar ; 55–64 chaikaew, n., n. k. tripathi, and m. souris (2009). exploring spatial patterns and hotspots of diarrhea in chiang mai, thailand. international journal of health geographics, 8(1); 36 chen, p., t. chen, and h. yuan (2010). gis based crime risk analysis and management in cities. in the 2nd international conference on information science and engineering. ieee chen, p., h. yuan, and d. li (2012). space-time analysis of burglary in beijing. security journal, 26(1); 1–15 endrawati (2016). analysis of 2016 hotspots and areas of forest and land fires . jakarta: directorate of inventory and monitoring of forest resource. director general of forestry planning and environmental management ministry of environment and forestry hantson, s., m. padilla, d. corti, and e. chuvieco (2013). strengths and weaknesses of modis hotspots to characterize global fire occurrence. remote sensing of environment, 131; 152–159 hayasaka, h., k. yamazaki, and d. naito (2019). weather © 2020 the authors. page 32 of 33 sari et. al. indonesian journal of environmental management and sustainability, 4 (2020) 28-33 figure 10. charts in 2018 figure 11. charts in 2019 conditions and warm air masses during active fire-periods in boreal forests. polar science, 22; 100472 kirana, a. p., i. s. sitanggang, and l. syaufina (2016). hotspot pattern distribution in peat land area in sumatera based on spatio temporal clustering. procedia environmental sciences, 33; 635–645 mahmud, m. (2017). active fire and hotspot emissions in peninsular malaysia during the 2002 burning season. geografia-malaysian journal of society and space, 1(1) martino, f. d., w. pedrycz, and s. sessa (2018). spatiotemporal extended fuzzy c-means clustering algorithm for hotspots detection and prediction. fuzzy sets and systems, 340; 109–126 martino, f. d. and s. sessa (2018). extended fuzzy cmeans hotspot detection method for large and very large event datasets. information sciences, 441; 198–215 mouillot, f., m. g. schultz, c. yue, p. cadule, k. tansey, p. ciais, and e. chuvieco (2014). ten years of global burned area products from spaceborne remote sensing—a review: analysis of user needs and recommendations for future developments. international journal of applied earth observation and geoinformation, 26; 64–79 prayoga, m., a. yananto, and a. kusumo (2017). correlation analysis of hotspot density with rainfall on the islands of sumatra and kalimantan. journal of weather modification science and technology, 18(1); 17–24 rasyid, f. (2014). problems and impact of forest fires. widyaiswara circle journal, 1(4); 47–59 santosa, b. j., n. saadah, r. sumaningsih, and a. h. ngestiningrum (2018). spatial analysis of dengue hemorrhagic fever in the endemic area of magetan. health notions, 2(4); 460–465 shah, s. a., h.-m. neoh, s. s. s. a. rahim, z. i. azhar, m. r. hassan, n. safian, and r. jamal (2014). spatial analysis of colorectal cancer cases in kuala lumpur. asian pacific journal of cancer prevention, 15(3); 1149– 1154 tacconi, l. (2016). preventing fires and haze in southeast asia. nature climate change, 6(7); 640 usman, m., i. s. sitanggang, and l. syaufina (2015). hotspot distribution analyses based on peat characteristics using density-based spatial clustering. procedia environmental sciences, 24; 132–140 ward, m. p. (2007). spatio-temporal analysis of infectious disease outbreaks in veterinary medicine: clusters, hotspots and foci. vet ital, 43(3); 559–570 zubaidah, a. and m. arief (2004). spatial distribution of hot spots and smoke distribution indicators of forest / land fires on the islands of sumatra and kalimantan in 2002. journal of remote sensing and digital image data processing, 1(1); 56–65 © 2020 the authors. page 33 of 33 introduction experimental section material method results and discussion conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper chemical oxygen demand (cod) and total suspended solid (tss) removal from rubber wastewater factory using electrocoagulation technique andika munandar1*, khairratul nabila1, rifka noor azizah1 1environmental engineering study program, institut teknologi sumatera, lampung selatan, 35365, indonesia *corresponding author e-mail: andika.munandar@tl.itera.ac.id abstract rubber industrial wastewater is obtained during washing, shredding, grinding, crumbbing, drying, and pressing bokar. the wastewater produced can be an environmental pollutant because it contains relatively large amounts of organic matter. one alternative to treating rubber wastewater is to use the electrocoagulation process, which is a combination of the coagulation and electrolysis processes. this electrocoagulation process has several advantages in the form of simple equipment, short time, produces odorless wastewater, does not require large areas of land, and can remove various contaminants in water. in this study, rubber wastewater was treated by electrocoagulation using a batch system with variations in the contact time used, namely 20, 40, 60, 80, and 100 minutes. this type of research is experimental research, and descriptive analysis is carried out. rubber wastewater is physically gray-black before treatment and chemically contains large organic matter. the results of this study showed that the content of chemical oxygen demand (cod) and total suspended solids (tss) before processing had values of 691 mg/l and 317 mg/l. optimum conditions for the elimination of cod and tss contents were achieved within 80 minutes with the percentage of elimination being 89% and 85%. keywords cod, electrocoagulation, rubber wastewater, tss received: 8 december 2022, accepted: 12 march 2023 https://doi.org/10.26554/ijems.2023.7.1.27-31 1. introduction natural rubber is the most important raw material for the rubber industry. the development of the rubber industry has had a positive impact on the country in the form of foreign exchange and economic population growth. in addition to the positive effects, the development of the rubber industry also pollutes the environment in the form of industrial wastewater that does not meet the carrying capacity and pollutant load when discharged into water bodies (yasin, 2018). wastewater rubber is produced in processes of washing, shredding, milling, shredding, drying, and bokar pressing processes (dewi et al., 2020). the properties of wastewater rubber before treatment show a chemical oxygen demand (cod) value of up to 911 mg/l, and a total suspended solid (tss) of 618 mg/l (ariyani and mulyono, 2015). compared with the quality standards for liquid rubber effluent according to minister of the environment regulation no. 5 of 2014 the maximum cod content in rubber wastewater is 200 mg/l, and the maximum tss content is 100 mg/l (mayasari et al., 2020). the cod and tss values of the material do not meet quality standards and require further treatment before being discharged into the landfill and body of water. wastewater rubber treatment in general consists of anaerobic, facultative, and aerobic ponds with this pond system there are drawbacks, country, long-term residence, potential odor, caution required, and still no contaminants produced meet quality standards (prawiranti et al.). several other rubber treatments, namely filtration, actived sludge and adsorption have been used in the treatment of rubber. among these treatments, they still have drawbacks, namely, they are only able to remove suspended solids and the occurrence of blockages in the pores (hutagalung, 2018). therefore, a more effective treatment is needed to reduce the pollutants contained in rubber and can be more efficient in terms of cost and time (nurhayati et al., 2013). one alternative for handling rubber processing wastewater is coagulation because coagulation has two methods, namely conventional coagulation and electrocoagulation. besides that the reduction of total suspended solids in wastewater is dominated by the coagulation method (teh et al., 2016). electrocoagulation is a combination of electrolysis https://doi.org/10.26554/ijems.2023.7.1.27-31 munandar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 27-31 and coagulation processes. this electrocoagulation method is very simple and efficient in the wastewater treatment (rusdianasari et al., 2017). some of the advantages of this electrocoagulation method are the simple equipment used, the short reaction time, and the odorless product. wastewater does not require a large area (ukiwe et al., 2014), and can remove many types of contaminants wastewater (wiyanto et al., 2014). based on the research conducted by fitri et al. (2020) found that the percentage level of removal of cod and tss levels in the of fishery activities using the electrocoagulation method that is equal to 82.89% and 31.90% which occurs at a voltage of 12 volts within 60 minutes and 15 minutes (radityani et al., 2020). then the research conducted by ni’am et al. (2017) showed that the optimum conditions for removal of cod and tss levels in textile wastewater were obtained at a voltage of 12 volts within 45 minutes with a percentage level of removal of cod and tss levels of 76% and tss of 85%. based on the description, it can be seen that the electrocoagulation method can reduce the levels of cod and tss in wastewater. the electrocoagulation method can be used as an alternative treatment for rubber as the object of this research. in this electrocoagulation process, aluminum electrodes are used because it has good electrical conductivity, is corrosion resistant, and has good reducing properties. 2. experimental section the wastewater of rubber used in this study was collected at the inlet of a sewage treatment plant and treated using electrocoagulation with contact time variations of 20, 40, 60, 80, and 100 minutes. the electrocoagulation process uses a batch system with a capacity of 500 ml, the type of electrode used is aluminum with a size of 7 × 10 cm as many as 2 pieces, the distance between the electrodes is 2 cm, and the voltage used is 12 volts. the parameters studied in this study were levels of cod and tss. 3. results and discussion 3.1 characteristics of wastewater rubber characteristics of liquid rubber waste include physical, chemical, and biological characteristics. in this study, the quality of wastewater rubber can be measured physically and chemically. physical measurements can be seen from the levels of suspended solids contained in rubber, while chemical measurements can be seen from the levels of organic substances in rubber. the liquid rubber waste taken from the inlet of the wastewater treatment process (wwtp) in this study can be physically seen as very cloudy, smells very pungent, is gray-black, and contains high organic compounds. the following is a picture of rubber before it is processed (figure 1). characteristics of rubber before processing using the figure 1. rubber before processing table 1. the results of the initial test of the cod and tss parameters of liquid rubber waste parameter unit quality standards test results cod mg/l 200 691±7.57 tss mg/l 100 317±37.745 electrocoagulation method must pay attention to the quality standard criteria contained in the regulation of the minister of the environment no. 5 of 2014 concerning wastewater quality standards. the results of the initial characteristics of rubber obtained from the results of laboratory analysis can be seen in the table 1. based on the table above, it can be seen that the values of cod and tss levels before processing are still not by the established quality standards. the results of the initial test for cod and tss levels were respectively obtained for cod of 691 mg/l and tss of 317 mg/l. the quality standard values for cod and tss levels in the minister of environment regulation no. 5 of 2014 are 200 and 100 mg/l, respectively. the high levels of cod and tss are contained in rubber, so it needs to be treated first before being discharged into water bodies. based on several previous studies, it was stated that the levels of cod and tss in rubber still exceeded the quality standard of rubber. in a study conducted by ariyani and mulyono (2015), it was stated that the characteristics of rubber before being processed had cod levels reaching 911 mg/l and tss 618 mg/l. then the research conducted by naswir et al. (2020) also stated that the initial content of cod and tss in rubber before processing was cod of 1415 mg/l and tss of 340 mg/l. this can prove that the levels of cod and tss in rubber have high levels and do not meet the quality standards of rubber. © 2023 the authors. page 28 of 31 munandar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 27-31 figure 2. percentage of cod removal 3.2 analysis of cod removal in rubber cod measurement aims to see the degree of pollution contained in wastewater. in the treatment of rubber using the electrocoagulation process, the cod measurement results are obtained, and then the results from the cod level measurements are calculated as the percentage of removal. based on the calculation of cod removal, a graph of the cod removal percentage can be obtained, which is shown in figure 2. based on figure 2, it can be seen that variations in contact time affect the percentage of cod removal in rubber. cod removal percentage starts from 0% to 89%. the percentage value of cod removal at contact time (20, 40, 60, and 80 minutes) increased, while at 100 minutes it decreased. the highest cod removal percentage occurred at 80 minutes, which was 89%. while the lowest cod removal percentage occurred at a contact time of 20 minutes with a removal rate of 54%. table 2. result for chemical oxygen demand electrode results references al-al 89% this research al-al 98.74% (fakorede and adewumi, 2020) al-al 86.82% (wiyanto et al., 2014) based on table 2, it can be seen the difference in the results from the use of al electrodes found on the cathode and anode both from this study with other studies such as fakorede research and wiyanto research which shows a percentage decrease in cod values and produces sludge in the form of al(oh)3. the increase in the percentage of cod removal in rubber after processing using the electrocoagulation process is due to a reduction process that occurs at the cathode and oxidation that occurs at the anode. the reactions that occur at the anode and cathode are as follows: reaction at the anode: al(s) ⇌ al 3+ (aq) + 3e− reaction at cathode: 2h2o(l) + 2e − ⇌ h2(g) + 2oh − (aq) based on the reaction that occurs at the anode and cathode using aluminum electrodes, the results of the reaction are: al(s) + 3h2o(l) ⇌ al(oh)3(s) + 3/2h2(g) the electrocoagulation process that occurs at the anode will result in the dissolution of aluminum metal to produce al3+ ions. al3+ ions formed in the reaction at the anode will react with oh− ions to form solid al(oh)3, which is insoluble in water. the solid al(oh)3 formed in the solution can then function as a coagulant in the electrocoagulation process (hanum et al., 2015). furthermore, the coagulant formed will make the colloidal particles in the water unstable. then the unstable colloidal particles will lose their charge, and the particles will form flocs. meanwhile, the reduction reaction that occurs at the cathode will produce h2 gas, where the gas functions to lift the floc that binds the contaminants contained in the liquid rubber waste to the surface (nidheesh et al., 2022). the floc formed over time will get bigger and will settle to the bottom of the beaker glass. the longer the electrocoagulation process, the more coagulants are produced to bind contaminants, resulting in a better decrease in cod levels in wastewater. after the electrocoagulation process is complete, the anode is marked by the eroding of the aluminum plate as a sign of the production of metal ions. while at the cathode, hydroxyl ions and hydrogen gas will be produced. the appearance of hydrogen gas is indicated by the presence of gas bubbles during the electrocoagulation process, resulting in foam on the surface of the glass. in addition, the cathode is marked by the appearance of white spots as a sign that hydrogen gas is produced on the cathode plate (apriyanto et al., 2018). based on the results of the cod measurements obtained, at the 60, 80, and 100 minutes, they have met the quality standards stipulated in the regulation of the minister of the environment no. 5 of 2014 concerning wastewater quality standards, where the quality standard for cod levels in rubber is 200 mg/l. 3.3 analysis of tss allowance in liquid rubber waste tss measurement is intended to determine the number of solids that are not dissolved in wastewater. the results of testing the levels of tss in rubber before being given electrocoagulation treatment obtained a tss content of 317 mg/l. the amount of tss levels obtained, so it is necessary to treat rubber first before being discharged into water bodies. after obtaining the tss content from each time variation used, the percentage of tss removal in rubber was calculated. the percentage of tss allowance can be seen in figure 3. © 2023 the authors. page 29 of 31 munandar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 27-31 figure 3. percentage of tss removal based on figure 3, it can be seen that variations in contact time can affect the percentage of tss removal in rubber. the percentage of tss removal in rubber fluctuates or fluctuates. the percentage value of tss removal has a range of 0% to 85%. the highest tss removal percentage occurred at a contact time of 80 minutes with a tss removal percentage of 85%. while the lowest percentage of tss removal occurred at a contact time of 20 minutes with a tss removal percentage of 52%. table 3. results for total suspended solid electrode results references al-al 85% this research al-fe 73% (massoudinejad et al., 2015) al-al 89% (zailani et al., 2018) based on table 3, it can be seen the difference in the results from the use of al electrodes or with other electrodes such as fe found on the cathode and anode both from this study with other studies such as massoudinejad research and zailani research which shows a percentage decrease in tss values and produces sludge in the form of al(oh)3 and fe(oh)3. the increase in the percentage of tss removal in rubber occurs due to the formation of al(oh)3. the longer contact time used will be directly proportional to the amount of charge that flows during the electrocoagulation process. this causes more metal ions to stick to the electrodes, resulting in the removal of levels. 5 of 2014 concerning wastewater quality standards, where the quality standard for tss levels in rubber is 100 mg/l. 4. conclusions from the results of research regarding the treatment of liquid rubber waste for cod and tss removal using the electrocoagulation method, the conclusions that can be obtained from the results of this study are the initial characteristics of rubber before processing using the electrocoagulation method, namely the cod content of 691 mg/l and the tss of 317 mg/l. the highest percentages of cod and tss removal occurred at 80 minutes at 89% and 85%, respectively. 5. acknowledgement on this occasion, with all humility, we would like to thankthe, we also thank the institut teknologi sumatera and the reviewers who have improvedour manuscripts better. hopefully this journal will be usefulfor the readers of this journal. references apriyanto, a., s. daud, and h. edward (2018). pengaruh kuat arus dan waktu kontak pada proses elektrokoagulasi menggunakan sel al-al dengan ketebalan 1 mm untuk penyisihan tds dari limbah cair lumpur bor. jurnal online mahasiswa (jom) bidang teknik dan sains, 5; 1–6 (in indonesia) ariyani, s. b. and a. s. mulyono (2015). kemampuan lumpur aktif biakan campuran dari limbah industri crumb rubber untuk mengurangi kadar cod, bod dan tss. majalah biam, 11(1); 11–16 (in indonesia) dewi, d. s., h. e. prasetyo, and e. karnadeli (2020). pengolahan air limbah industri karet remah (crumb rubber) dengan menggunakan reagen fenton. jurnal redoks, 5(1); 47–57 (in indonesia) fakorede, e. and j. adewumi (2020). effectiveness of electro-coagulation treatment method on the physiochemical parameters and heavy metals in rubber 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(2018). elektrolisis limbah cair industri pelapisan logam dengan menggunakan elektroda aluminium untuk menurunkan kadar logam kromium (cr), zink (zn), dan kadmium (cd). repositori institusi universitas sumatera utara (in indonesia) massoudinejad, m., m. mehdipour-rabori, and m. hadi dehghani (2015). treatment of natural rubber industry wastewater through a combination of physicochemical and ozonation processes. journal of advances in environmental health research, 3(4); 242–249 mayasari, r., e. purba, and m. djana (2020). penyisihan © 2023 the authors. page 30 of 31 munandar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 27-31 kadar amoniak (nh3) dalam limbah cair karet dengan kombinasi adsorben bentonit dan zeolit secara kontinyu. prosiding seminar nasional ilmu teknik dan aplikasi industri fakultas teknik universitas lampung, 3; 110 (in indonesia) naswir, m., y. yasdi, m. a. chaniago, and y. g. wibowo (2020). pemanfaatan kompilasi bentonit dan karbon aktif dari batubara untuk menurunkan kadar bod dan cod pada limbah cair industri karet. jurnal presipitasi: media komunikasi dan pengembangan teknik lingkungan, 17(2); 121–127 (in indonesia) nidheesh, p., b. behera, d. s. babu, j. scaria, and m. s. kumar (2022). mixed industrial wastewater treatment by the combination of heterogeneous electro-fenton and electrocoagulation processes. chemosphere, 290; 133348 ni’am, a. c., j. caroline, and m. h. afandi (2017). variasi jumlah elektroda dan besar tegangan dalam menurunkan kandungan cod dan tss limbah cair tekstil dengan metode elektrokoagulasi. jurnal teknik lingkungan, 3(1); 21–26 (in indonesia) nurhayati, c., b. hamzah, and r. pambayun (2013). optimasi pengolahan limbah cair karet remah menggunakan mikroalga indigen dalam menurunkan kadar bod, cod, tss. jurnal dinamika penelitian industri, 24(1); 16–26 (in indonesia) prawiranti, y., n. wahyuni, and a. h. alimuddin (). waste water treatment of crumb rubber industry by photocatalysts ag/zaa-tio2. orbital: jurnal ilmu dan terapan kimia, 1(2); 44–58 radityani, f. a., s. hariyadi, s. suprihatin, d. h. y. yanto, and s. h. anita (2020). penerapan teknik elektrokoagulasi dalam pengurangan bahan organik air limbah kegiatan perikanan. jurnal ilmu pertanian indonesia, 25(2); 283–290 (in indonesia) rusdianasari, r., a. taqwa, j. jaksen, and a. syakdani (2017). treatment of landfill leachate by electrocoagulation using aluminum electrodes. matec web of conferences, 101; 02010 teh, c. y., p. m. budiman, k. p. y. shak, and t. y. wu (2016). recent advancement of coagulation–flocculation and its application in wastewater treatment. industrial & engineering chemistry research, 55(16); 4363–4389 ukiwe, l., s. ibeneme, c. duru, b. okolue, g. onyedika, and c. nweze (2014). chemical and electro-coagulation techniques in coagulation-flocculation in water and wastewater treatment: a review. journal of advances in chemistry, 9(3); 2321–807 wiyanto, e., b. harsono, a. makmur, r. pangputra, j. julita, and m. s. kurniawan (2014). penerapan elektrokoagulasi dalam proses penjernihan limbah cair. jetri: jurnal ilmiah teknik elektro, 12(1); 19–36 (in indonesia) yasin, a. (2018). manajemen limbah pabrik karet dalam rangka penurunan kadar bod (biological oxygen demand). jurnal green growth dan manajemen lingkungan, 7(1); 22–34 (in indonesia) zailani, l. m., n. m. amdan, and n. zin (2018). removal efficiency of electrocoagulation treatment using aluminium electrode for stabilized leachate. iop conference series: earth and environmental science, 140(1); 012049 © 2023 the authors. page 31 of 31 introduction experimental section results and discussion characteristics of wastewater rubber analysis of cod removal in rubber analysis of tss allowance in liquid rubber waste conclusions acknowledgement indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article received: 26 november 2017 accepted:24 march 2018 *corresponding author email:riam_amsya@yahoo.com doi: 10.26554/ijems 2018.2.15-1915 investment estimation and acceptance of state tax instead of coal mining business license clear and clean in west sumatera province riam marlina a 1, fachrurrozie sjarkowi1, maulana yusuf 2 1 postgraduated of mining engineering, sriwijaya university, south sumatera, indonesia 2 associate professor/head of mining engineering departement, sriwijaya university, indonesia abstract this research conceptual measurement simulation for financial component which is needed for investment and benefit simulation held by stated that taken from company obligation categorized as non-tax for mining activities predicated with clear and clean at west sumatera province. this simulation connected with capital investment and operational activities that influenced by coal getting stripping ratio, coal hauling and other financial related. this simulation only values stated income non tax and royalty. analysis methods using from several document feasibility study from coal company has already operated, and also estimation for all investment component and components of income stated non tax. accuracy data accepted for this research at least 30% from all investment. estimation starting from deciding production target, life mining period, investment needs financial operation and other financial activities, and comparison with theoretical measurement. the comparison result then used to make another financial model simulation. at the last, this research will present economy simulation model created from mining operational activities in west sumatra province to estimate stated income non tax from mining production operational. using sensitivity analysis, shows that the change of coal selling prices will gives significant influence to npv project and stated income non tax. keywords: estimation, investment, non tax, clear and clean, simulation, 1. introduction this research do conceptually calculation the costs required for investment as well as the calculation of the profit obtained from the obligation of the state of the company in the form of the acceptance of the state is not against tax clear and clean coal mining in west sumatera. the simulation is associated with the magnitude of the investment costs and operation of which depends on the selling price of coal, stripping ratio and transport distances, as well as other costs. simulation of the acceptance of the country's only counting admissions state tax instead of a fixed royalty dues and dues. this research was limited against the special status of coal mining licences clear and clean in the province of west sumatera. the purpose of this research is create a conceptual model of investment estimation and a conceptual model of the country instead of taxes from iup clear and clean coal in west sumatera. 2. experimental section this research uses descriptive comparative method. type of data used as analysis research is secondary data. the secondary data were used, among others: 2.1 the investment the estimated cost of the investment or capital cost is calculated by estimation the production capacity of coal per day or per year and life of mine. this estimation process according to wijaya [1] based on a formula of tylor [2] or known as tylor's rules that have been proven by mc spadden & schaap [3] and camm [4]. the formula is as follows: production capacity = [coal reserve]0.75÷70 (1) life of mine = 0.2 x √coal reserve4 (2) the investment costs can be calculated using the formula results o'hara & suboleski [5] which has been verified by shafiee, nehring and topal [6] used are as follows: cost of investment (us $)=$400.000 x (coal of mine) 0.6 (3) stebbins and leinart [7] in wijaya stating the above formula based on several components that stand out among other investments in exploration, production, job before working capital, purchase of mining equipment and processing, development costs, infrastructure costs, engineering and construction management, building and property purchases, and other costs (contingency). author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.15-1916 2.2 costs operation operating costs are the costs incurred to produce or digging coal, to connections to the port. this cost component reference using data from the directorate general of mineral and coal decision no.579.k/32/rtg/2015, about the cost of production for the determination of the price of coal to the year 2015. in the appendix mentioned, that production costs are assigned based on the type of costs which consist of direct production costs, production costs, and indirect costs general and administrative. some of the costs incurred in the period before the operation of the production, especially in component costs, necessitating investment in map out to the present (2017). to do that, the projection used marshall & swift mining and milling equipment cost index. the index used to compare between price/cost of a given year (past), with the price/cost of the current year or in the future, so as to provide an overview of the costs that will be incurred. the above charges will be multiplied by a factor of escalation index marshall & swift until the age of the project, except for the cost of amortization, liberation/ replacement land and depreciation, fixed dues and assuming the cost of production/royalty. the equation used to calculate the cost at this time are as follows: 𝐶𝐶𝑡𝑡 = 𝐶𝐶𝑂𝑂 × ( 𝐼𝐼𝑡𝑡 𝐼𝐼𝑂𝑂 ) (4) description; ct = cost estimation when this year or will come co = cost in the previous year it = index marshall & swift this year or will come io = index marshall swift & previous year 2.3 price projections price predictions made in reference to australia with the thermal coal market equality calorie coal (gross water received) 6.322 kcal/kg gar or 6.800 kcal/kg of adb (air dried base), moisture content (total moisture) 8%, 0.8% sulfur levels ar (as received), and ash content 15% of the reference ar, then in the calculation of the price of coal in west sumatera is adapted to the coal quality. the formula used to calculate the price of coal from west sumatera with coal quality thermal reference equality, is the formula benchmark price of coal and mineral resources by the ministry, the marker with the following formula: the price of coal = (hba*k(i)*a(i))-(b(i)-u(i))(5) description; hba = coal price reference-thermal coal marker (gar) k (i) = heat value coal (i)/6322 kcal/kg a (i) = (100 – coal water content (i))/ (100 – 8/fka (i) fka (i) = {[(100 – 8)/(100 – coal water content (i))] * the moisture contentof coal (i)} + (100 – 8)/100 b (i) = (sulfur content of coal (i) – 0.8) * 3 u (i) = (ash content of coal (i) – 15) * 0.3 i = price marker 3. results and discussion 3.1 results the results of the processing of data regarding the cost of investment and the empirical formula yield data field as follows: a. production target based on figure 1 above can be shown that the bigger the reserves, then followed with an increase of annual production capacity. mpirical formulas resulting from the approach to coal reserves with an annual production target, are as follows; y = 0,169x0,526 (6) y is the ideal production goals with in one year (million tons) and x is mining coal reserves in a region or a concession (million tons). to predict life of mine of the graph of figure 2 obtained empirical formula as follows: y = 3,095e0,244x (7) y is the ideal life of mine in years, and x is a variable of the coal reserves of the mine in a million tons in a licenses. b. total cost of investment the total investment cost estimation calculations carried out using emperis equation is obtained from the processing of the data. match with the magnitude of the total cost of the affected 0.10 0.20 0.30 0.40 0.50 0.60 0.70 2.00 4.00 6.00 8.00 10.00 12.00 14.00 pr od uc tio n (x 1 m ill io n/ ye ar ) reserves (x1 million ton) production by formula production by fs production approach power (production approach) figure 1 formula of production approach 0 2 4 6 8 10 12 14 16 0,25 0,32 0,63 2,40 12,15 lif e of m in e (y ea r) reserves (x1 million ton) life of mine actual life of mine by formula figure 2 formula approach to life of mine author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.15-1917 investment against inflation, then used marshall & swift mine and mill equipment cost index. data documents the feasibility study regarding the magnitude of calculation of the cost of the investment at the time of the feasibility study carried out attempted on table 2. the total cost of the investment is obtained is then projected by using equation (4). the results of these calculations are compared with calculations based on the magnitude of the investment needs of production using equation (3). some of the data has a larger deviation than ± 30%, since the year is compared when making feasibility study to the needs of the investment of the year 2017. so with the results of the projection needs investment and the formulation of theoretical approach, empirical formula obtained to predict total investment needs in west sumatera. the formula is as follows; y = 3,163ln(x)+13,26 (8) y is the total needs of the investment in units of million – dollar (million $) and x is a variable target annual production in million tons. the graph of the results of the calculation produces the equation 8 can be seen in figure 3. c. price projection the projection of the price of coal was obtained from world bank australian coal price forecast or the world bank institute (2017) for thermal coal prices australia the period 2014 – 2030 published in march 2017. the following is the graph of the results of the regressions coal prices and coal in west sumatera with a wide range of quality until the year 2037. d. production scheduling estimated annual production target and life of mine is based on the assumption of reserve mining variations. the results generated from production scheduling. the simulation is made on an annual basis for each of the goals and appropriate life of mine. following is figure 5 simulating production and life of mine. e. feasibility assessment financial models company located on the cash flow simulation. summary the analysis of feasibility of investment coal mining in west sumatera that outlines the company's skill level in generating cash flow during the life of mine shown in table 4 below. the eligibility calculation in the table 4 below using a 10% of discount factors, these values using the method of approach to the weighted cost of capital or average weight average cost of capital (wacc). these methods are used because in the simulation calculation of cash flow, capital investment is part of the loan. f. estimation tax not country acceptance acceptance of state tax is not retrieved from the summation of results between fixed dues receipt estimation with estimated receipts royalty dues in one year. acceptance of state instead of taxes that are derived from the coal mining business license clear and clean which was in west sumatera province, with of 158.43 million tons. the formula approach resulting from a fixed dues and royalty dues, are as follows: y = 4x (8) y = 17215x + 58259 (9) y is the total acceptance of the state tax is not in units of $/year, and x is the variable price of coal. discussion west sumatera has the potential geology and the large coal reserves, as well as scattered in 5 (five) district/city, which can be developed by the prospective investors. the potential of the most high ranking coal quality (high calorie) with the range of 6300 – 7121 kcal/kg adb (air dried base). with coal price projection of sumbar coal 1 (6125 kcal/kg) = 63.27 us $/ton, sumbar coal 2 (6400 kcal/kg) = 64.87 us $/ton, sumbar coal 3 (6600 kcal/kg) = 67.78 us$/ton, sumbar coal 4 (6750 kcal/kg) = 69.36 us $/ton, sumbar coal 5 (7121 kcal/kg) = 72.10 us us$/ 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 0.00 0.20 0.40 0.60 0.80 in ve st m en t (x 1 m ill io ns $ ) production of the year (x1 million ton) investment by fs investment by teoritical investment by emperis figure 3 results total investment approach 40.00 45.00 50.00 55.00 60.00 65.00 70.00 75.00 80.00 85.00 2010 2020 2030 2040 pr ic e ($ /t on ) year cv 6800 kcal/kg adb cv 6125 kcal/lg adb cv 6400 kcal/kg adb cv 6600 kcal/kg adb cv 6750 kcal/kg adb cv 7121 kcal/kg adb figure 4 projection coal price of westsumatera 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.00 5.00 10.00 15.00 0 10 20 30 40 50 60 70 pr od uc tio n (m ill io n to n/ ye ar ) reserve (million ton) lif e of m in e (y ea r) life of mine production figure 5 simulation production and life of mine author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.15-1918 ton. with the fob barge or fot barge varies. sawahlunto to alternate fot-barge to pltu sijantang 4.5 km distance, when alternative fob-barge to port of teluk bayur with distance of 125 km. south pesisir regency when fot-barge to port patapahan painan with distance 25 km counts when fot-barge to the port of teluk bayur then distance of 125 km. where as for sijunjung, dharmasraya regency and city 50 fot-barge to the port of teluk bayur with a distance of 135 km, 150 km and 165 km away. estimation of the acceptance of the country instead of taxes is the result of addition of predictions dues remain with the predictions of the royalty dues. prediction model of estimation of dues still use formula formula to calculate and 8 prediction formula using royalty dues 9. table 4 summary of the assessment of the feasibility of the various models of investment coal mining in west sumatera description variable unit stripping ratio distance sumbar sumbar sumbar sumbar sumbar coal 1 coal 2 coal 3 coal 4 coal 5 quality of coal kcal/kg 6125 6400 6600 6750 7121 price projection us$/ton 63,27 64,87 67,78 69,36 72,10 sawahlunto fob barge 4,5 km 11 11 11 12 13 125 km 7 7 7 9 9 dcf-(npv i = 10%) 4,5 km $27.52 $27.37 $27.37 $22.03 $19.77 irr 12% 12% 12% 11% 11% pp 9,53 9,54 9,54 8,49 10,42 arr 21,41% 21,38% 21,38% 20,19% 19,69% bc ratio 1,22 1,22 1,22 1,21 1,21 dcf-(npv i = 10%) 125 km $44.33 $44.18 $44.18 $38.83 $36.58 irr 15% 15% 15% 14% 13% pp 8,03 8,04 8,04 8,49 8,70 arr 25,33% 25,30% 25,30% 24,10% 23,60% bc ratio 1,25 1,25 1,25 1,24 1,24 south pesisir fob barge 25 km 10 10 10 11 12 125 km 7 7 7 9 9 dcf-(npv i = 10%) 25 km $44.88 $44.73 $44.73 $39.39 $37.13 irr 15% 15% 15% 14% 14% pp 7,98 7,99 7,99 8,45 8,65 arr 25,46% 25,43% 25,43% 24,23% 23,73% bc ratio 1,25 1,25 1,25 1,24 1,24 dcf-(npv i = 10%) 125 km $44.33 $44.18 $44.18 $38.83 $36.58 irr 15% 15% 15% 14% 13% pp 8,03 8,04 8,04 8,49 8,70 arr 25,33% 25,30% 25,30% 24,10% 23,60% bc ratio 1,25 1,25 1,25 1,24 1,24 sijunjung, dharmasraya, 50 kota fob barge 135 km 7 7 7 9 9 150 km 7 7 7 8 9 165 km 6 6 6 8 8 dcf-(npv i = 10%) 135 km $46.43 $46.33 $46.33 $42.51 $40.78 irr 15% 15% 15% 14% 14% pp 7,80 7,80 7,80 8,12 8,26 arr 25,66% 25,64% 25,64% 24,79% 24,40% bc ratio 1,25 1,25 1,25 1,25 1,24 dcf-(npv i = 10%) 150 km $25.93 $25.83 $25.83 $22.01 $20.28 irr 12% 12% 12% 11% 11% pp 9,62 9,63 9,63 10,07 10,28 arr 20,89% 20,86% 20,86% 20,01% 19,63% bc ratio 1,22 1,22 1,22 1,21 1,21 dcf-(npv i = 10%) 165 km $50.81 $50.70 $50.70 $46.88 $45.16 irr 16% 16% 16% 15% 15% pp 7,48 7,49 7,49 7,78 7,92 arr 26,68% 26,66% 26,66% 25,81% 25,42% bc ratio 1,26 1,26 1,26 1,25 1,25 author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems.2018.2.15-1919 conclusion results from simulation conceptually retrieved early picture, that business investment mining in west sumatera deserves to be developed on the condition and specific scenarios. factors affecting the investment estimation and acceptance of state tax is not the ups and downs of the price of coal, the initial investment cost of the her little big, and operational costs. changes to the components of the selling price of coal has significant effects against the rate of return or net present value (npv) of the project. references [1] wijaya, e.conceptual study of economic valuation of investments and projects of coal mine in south sumatra. thesis. sriwijaya university. 2015. [2] tylor, h.k. mine valuation and feasibility studies, mineral industry cost. northwest mining association, washington, pp18. 1977. [3] mc spadden, g. & schaap, w. technical note: tylor’s of mine life. proc australasia inst. min. metal, pp. 217-220. 1984. [4] camm, t.w. simplified cost model for prefeasibility mineral evaluation. u.s. bureau of mines, spokane-washington, pp. 35. 2008. [5] o’hara t.a & suboleski s.c. costs and cost estimation in hartman, h.l (ed.) sme mining engineering handbook 2nd edition. sme inc.: new york, vol. 1, pp 2394 . 1992. [6] shafiee, s., nehring, m., topal, 2009. estimating average total cost of open pit coal mines in australia. australian mining technology conference. [7] stebbins, s.a, leinart, j.b. cost estimating for surface mines in darling, p. (ed.) sme mining engineering handbook third edition. sme inc.: california, pp 1832. 2011. title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper determinants analysis of public perception of waste bank as an alternative of settlement waste management tri hikmah abdi ningrum1, hilda zulkifli2, rahmi susanti3* 1department of biology teaching program. faculty of sciences. sriwijaya university. jalan padang selasa 524. palembang. south sumatera 30139. indonesia. 2department of biology. faculty of mathematics & natural sciences. sriwijaya university. jalan raya palembang-prabumulih km 32. indralaya. indonesia. department of biology education. faculty of teacher training and education. sriwijaya university. jalan raya palembang-prabumulih km 32. indralaya. indonesia. *corresponding author e-mail: hikmahtri23@yahoo.co.id abstract the activities of the waste bank is giving a positive impact on environment and increasing the public economy. this research aims to analyze the public perception of kebumen gemilang sejahtera (kgs) waste bank in kampung iklim 2 ilir, palembang. the population of this study was 639 households and there were 90 households as respondents. this study used a quantitative method by cross-sectional design. the data collection instrument was a questionnaire, observations, interviews, and documentation. data were analyzed by using multiple logistic regression. the results showed that the perception of the public (52.2%) of the waste bank categorized as good. characteristics of the community are mostly aged ≤42 years old (53.3%), mostly female (63%), highly educated (>sma) of 87.8%, good knowledge (70.0%), including the length of stay at the old enough category (57.8%), and has the highest employment as a housewife (42.2%). the results of multiple logistic regression showed that the length of stay variable (or=0.701) affects the public perception of the waste bank. keywords waste, waste bank, public perception received: 3 june 2020, accepted: 19 june 2020 https://doi.org/10.26554/ijems.2020.4.2.43-47 1. introduction waste is the rest of human daily activities and or solid natural processes (nugraha et al., 2018). waste management has become a complex problem. most of these wastes enter the landfill in a state of mixing between organic and inorganic waste (jimmyanto et al., 2018). the data shows that, so far waste management has not applied the principle of reduce, reuse, and recycle (3r) by involving optimal public participation. based on these problems, waste management is still concentrated in landfill (nugraha et al., 2018). so, a new paradigm in waste management is needed. changes to the new paradigm with the 3r concept can be integrated into community-based waste bank projects (asteria and heruman, 2016). a waste bank is a place for selecting and collecting waste that can be recycled and or reused that has economic value, which is a waste management concept integrating the 3r principle of reduce, reuse and recycle which carried out from, by and for the community (nugraha et al., 2018). the development of waste bank aims to assist the government in empowering the community to manage community-based waste wisely and can reduce the waste which transported to the landfill (purba et al., 2014). one of the waste bank that has been actively operating in palembang is the kebumen gemilang sejahtera (kgs) waste bank. kgs waste bank is a part of climate mitigation or prevention activities contained in the kampung iklim program in palembang. so far, public participation is still not optimal. there have only been around 15 people who have joined as active customers of the kgs waste bank. public participation also does not meet the standards of waste bank management as stipulated in minister of environment regulation no. 13, 2012 related to the role of waste savers or waste bank customers, which is sorting activities and efforts to reduce waste. public participation that has not been optimal in the kgs waste bank project can be further reviewed through the public perception of the existence of the waste bank. perception is the stage of a person’s assessment of an https://doi.org/10.26554/ijems.2020.4.2.43-47 ningrum et. al. indonesian journal of environmental management and sustainability, 4 (2020) 43-47 object (pasek, 2013). public perception of the kgs waste bank project is important because it can be the way to find out which components are the main problem of low public’s participation in the waste bank, so can get some solutions which can be obtained as a key to the success of the kgs waste bank as a community partner to reach a residential environment active in adaptation and mitigation efforts to climate change as stipulated in the kampung iklim program. 2. experimental section 2.1. location and schedules this research was carried out in february 2020 in the settlement area of kampung iklim 2 ilir palembang. the location of this study was carried out in four rt areas, namely rt 27, rt 28, rt 30, and rt 31. the selection of research sites is based on the existence of kampung iklim 2 ilir which has a kebumen gemilang sejahtera (kgs) waste bank that has been actively operating, but the public participation in the kgs waste bank is still not optimal yet. 2.2. design of study this study used a quantitative method by cross-sectional design. data collected to measure several variables is carried out by distributing questionnaires and interviews. 2.3 data and sourcesy data collected in this study are primary and secondary data. primary data in this study are respondents’s perceptions of kgs waste bank obtained from questionnaire and interview data and also data acquisition of respondents’ knowledge of waste and waste bank obtained from filling multiple-choice questions which answered by respondents. the secondary data in this study is the number population of rt 27, 28, 30, and 31 totaling 639 households obtained from kelurahan 2 ilir palembang. 2.4. methods this study used an analytic observational method with a cross-sectional design that aims to analyze the public perception of kgs waste bank in kampung iklim 2 ilir palembang by quantitative methods. the total population in that study was 639 households with a total sample was 90 respondents. variable in that study consist of dependent and independent variable. the dependent variable is public perception while the independent variables consist of age, gender, education level, knowledge, length of stay, and employment status. data is then analyzed by univariate, bivariate, and multvariate analysis. univariate analysis was performed to obtain a description of the frequency distribution and the percentage of the independent and dependent variables (ferosandi, 2018). bivariate analysis is used to examine the correlation or influence between independent and the dependent variable (ferosandi, 2018). the correlation between independent and dependent variables in this study is evidenced by the chisquare test with a confidence level of 95% (α=0.05 (zulkifli et al., 2019).) multivariate analysis is an analysis used to test more than two variables. public perception as dependent variable and age, gender, and length of stay variables as confounding variables were analyzed with multiple logistic regression analysis to determine the independent variables that are most related or influenced to the dependent variables based on the largest or values at the final modeling stage (ferosandi, 2018). 3. results and discussion the results of the univariate analysis show that most respondents are ≤ 42 years old (53.3%), and 70% are dominated by female respondents. the highest education of respondents was the high level of education (≥sma) of 87.8%, with a high level of knowledge which amounted to 70%. besides that, most of the respondents were people who had lived for a long time enough (≤ 30 years) in the kampung iklim kgs (57.8%) with the most employment status as a housewife (42.2%). meanwhile for the perception variable, it is known that 52.2% of respondents have a good perception of waste management and also the kgs palembang waste bank. the frequency distribution of the characteristics of respondents can be seen in table 1. the results of the bivariate analysis of the correlation of age to public perception can be seen in table 2. based on table 2, respondents >42 years old with good perception was 45.2%, while respondents with ≤42 years old with good perception was 58.3%. statistical results showed the p-value was 0.303. it is indicated that the p-value >α, which means that the age variable does not have a significant correlation to the respondents’ perception. the results showed that respondents >42 years old, tend to have a less favorable perception of kgs waste bank compared to respondents with ≤42 years old. the elderly group experiences a decrease in memory and understanding so that it can affect perception (afandi et al.). the results of the bivariate analysis of the correlation of gender to public perception can be seen in table 3. based on table 3, the number of male respondents with good perception was 33.3%, while the number of female respondents with good perception was 60.3%. the statistical results showed the p-value was 0,034. it is indicated that the p-value<α, which means that the gender variable has a significant correlation to the respondents’ perception. female respondents in this study had a better perception of waste and waste bank compared to male respondents. this is because most of those who are active in managing household waste and are also heavily involved in the activities of the waste bank are female respondents, so female respondents are more familiar with and have a good understanding of kgs waste bank. differences in values and traits based © 2020 the authors. page 44 of 47 ningrum et. al. indonesian journal of environmental management and sustainability, 4 (2020) 43-47 table 1. frequency distribution characteristics of kgs waste bank respondents number variables n % 1 age >42 years 42 46.7 ≤42 years 48 53.3 2 gender male 27 30 female 63 70 3 education level high (≥sma) 79 87.8 low (<sma) 11 12.2 4 knowledge high (>10) 63 70 medium (5-10) 23 25.6 low (<5) 4 4.4 5 length of stay old (>30 years) 38 42.2 old enough (≤ 30 years) 52 57.8 6 employment status housewifes 38 42.2 self-employed 16 17.8 bumn 3 3.3 civil servants 5 5.6 others 28 31.1 7 perception good (>47) 47 52.2 bad (≤47) 43 47.8 table 2. the correlation of age to public perception age public perception total % pvalue good bad n % n % n >42 years 19 45.2 23 54.8 42 100 0.303 ≤42 years 28 58.3 20 41.7 48 100 table 3. the correlation of gender to public perception gender public perception total % pvalue good bad n % n % n male 9 33.3 18 66.7 27 100 0.034 female 38 60.3 25 39.7 63 100 on gender will usually affect men and women in making decisions (hastuti, 2012). the results of the bivariate analysis of the correlation of education level to public perception can be seen in table 4. table 4. the correlation of education level to public perception education public perception total % pvalue level good bad n % n % n high 43 54.4 36 45.6 79 100 0.423 low 4 36.4 7 63.6 11 100 table 4 shows that the number of the high education levels of respondents with good perception was 54.4%, while the number of the low education levels of respondents with good perception was 36.4%. the statistical results showed the p-value was 0.423. it is indicated that the p-value>α, which means that the education level variable does not have a significant correlation to the respondents’ perception. so, as higher as the respondent’s education level did not affect on the higher perception. the results of the bivariate analysis of the correlation of knowledge to public perception can be seen in table 5. table 5. the correlation of knowledge to public perception knowledge public perception total % pvalue good bad n % n % n high 34 54 29 46 63 100 0.446 medium 10 43.5 13 56.5 23 100 low 3 75 1 25 4 100 the number of the high knowledge of respondents with good perception was 54.0%, the medium knowledge of respondents was 43.5%, while the low knowledge of respondents was 75.0%. the statistical results showed the p-value was 0.446. it is indicated that the p-value >α, which means that the knowledge variable does not have a significant correlation to the respondents’ perception. based on the results of observations and interviews conducted, there are some respondents with good knowledge about waste and its management, but respondents stated that the information they received about the waste bank tends to be not optimal. the availability of information significantly affects the level of public perception (irwan sukri banuwa et al., 2017). besides that, the activities and services provided by the waste bank also do not reach all people in that region yet. this causes even though respondents have good knowledge, but it raises a negative perception of the waste bank. in addition to functional factors, people’s perceptions can also © 2020 the authors. page 45 of 47 ningrum et. al. indonesian journal of environmental management and sustainability, 4 (2020) 43-47 be influenced by other factors, such as services obtained by respondents (zulkifli et al., 2019). the results of the bivariate analysis of the correlation of length of stay to public perception can be seen in table 6. table 6. the correlation of length of stay to public perception length public perception total % pvalue of stay good bad n % n % n old 17 44.7 21 55.3 38 100 0.317 old enough 30 57.7 22 42.3 52 100 based on table 6, the number of the length of stay of respondents of more than 30 years with good perception was 44.7%, while the length of stay of fewer than 30 years with good perception was 57.7%. the statistical results showed the p-value was 0.317. it is indicated that the p-value>α, which means that the length of stay variable does not have a significant correlation to the respondents’ perception. so, as higher as respondent’s length of stay did not affect on the higher perception. the results of the bivariate analysis of the correlation of employment status to public perception can be seen in table 7. table 7. the correlation of employment status to public perception employment status public perception total % pvalue good bad n % n % n housewifes 21 55.3 17 44.7 38 100 0.883 self-employed 7 43.8 9 56.3 16 100 bumn 1 33.3 2 66.7 3 100 civil servants 3 60 2 40 5 100 others 15 53.6 13 46.4 28 100 based on table 7, the highest good perception was obtained from employment status was housewives which were 21%. the statistical results showed the p-value was 0.883. it is indicated that the p-value>α, which means that the employment status variable does not have a significant correlation to the respondents’ perception. based on the results of observations and interviews conducted, the housewives often involved in the process of managing newspaper waste and plastic packaging to make new products in the kgs waste bank. this management activity can provide additional income which is very useful for them. the people will consciously participate in an activity if they feel there is a benefit for themselves, both directly and indirectly. conversely, individuals will not participate if that activities to be carried out are detrimental or do not provide any benefit (mohammadi et al., 2011). someone’s perception of an object will be positive if it suits their needs, on the contrary perception will be negative if it is not suited with their needs (irwan sukri banuwa et al., 2017). the results of multivariate analysis showed that the independent variable that most influenced the dependent variable was the length of stay variable because it had the highest or value, which was 0.701. this means that respondents with a length of stay in the old enough category can increase their perception of waste and kgs waste bank by 0.7 times higher than respondents with the length of stay in the old category in kampung iklim 2 ilir palembang. meanwhile, the age and length of stay variables have or change > 10% with p-value > 0.05 so that it is classified as a confounding variable. the result of final model can be seen in table 8. table 8. final model variables b p-value or 95% c.i. for exp (b) lower upper age -0.496 0.321 0.609 0.229 1.662 gender -1.198 0.016 0.302 0.114 0.798 length of stay -0.355 0.479 0.701 0.263 1.871 4. conclusions this study showed that the characteristics of the community are mostly aged ≤42 years old (53.3%), mostly female (63%), highly educated (≥sma) of 87.8%, good knowledge (70.0%), including a length of stay in the old enough category (57.8%), and has the highest employment as a housewife (42.2%). the majority of the public had a good perception of kgs waste bank (52.2%) and 47.8% of others were categorized as bad perception. the variable that has a significant relation to perception is the length of stay variable. acknowledgement the first author thanks to prof. dr. hj. hilda zulkifli, m.si., dea., dr. rahmi susanti, m.si. for their critical reviews on this study. the first author also thanks to yaumilia ismiranti putri, a research partner who has many roles in data collection. references afandi, y. v., h. r. sunoko, and k. kismartini (). status keberlanjutan sistem pengelolaan air limbah domestik komunal berbasis masyarakat di kota probolinggo. jurnal ilmu lingkungan, 11(2); 100–109 asteria, d. and h. heruman (2016). bank sampah sebagai alternatif strategi pengelolaan sampah berbasis masyarakat di tasikmalaya (bank sampah (waste banks) as an alternative of community-based waste management strategy © 2020 the authors. page 46 of 47 ningrum et. al. indonesian journal of environmental management and sustainability, 4 (2020) 43-47 in tasikmalaya). jurnal manusia dan lingkungan, 23(1); 136–141 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(2018). analisis persepsi masyarakat lingkungan industri karet remah di kota palembang. jurnal keperawatan sriwijaya, 5(1); 24–29 hastuti, s. (2012). perilaku etis mahasiswa dan dosen ditinjau dari faktor individual gender dan locus ff control (studi empiris pada fakultas ekonomi universitas x di jatim). jurnal riset ekonomi dan bisnis, 7(1); 58–73 irwan sukri banuwa, i., r. safe’i, w. christine wulandari, and f. indra gumay febryano (2017). analisis faktor-faktor yang mempengaruhi persepsi masyarakat dalam pembangunan hutan tanaman rakyat pada kph gedong wani. jurnal hutan dan masyarakat, 9(2); 61–74 jimmyanto, h., i. zahri, m. h. dahlan, and n. s. r. putri (2018). evaluasi sistem pengelolaan sampah padat domestik di kota palembang tahun 2017. demography journal of sriwijaya (dejos), 2(2); 1–7 mohammadi, s., s. norazizan, a. nobaya, and z. alireza soroush&emby (2011). relationship between citizen’s perception and level of participation in local government. in international conference on social science and humanity, volume 5. pages 431-435 nugraha, a., s. h. sutjahjo, and a. a. amin (2018). analisis persepsi dan partisipasi masyarakat terhadap pengelolaan sampah rumah tangga di jakarta selatan. journal of natural resources and environmental management, 8(1); 7–14 pasek, m. s. (2013). hubungan persepsi dan tingkat pengetahuan penderita tuberkulosis dengan kepatuhan pengobatan (di wilayah kerja puskesmas buleleng i). ph.d. thesis, uns (sebelas maret university) purba, h. d., c. meidiana, and d. w. adrianto (2014). waste management scenario through community based waste bank: a case study of kepanjen district, malang regency, indonesia. international journal of environmental science and development, 5(2); 212 zulkifli, h., m. faizal, et al. (2019). analisis determinan persepsi masyarakat di lingkungan sekitar industri farmasi pt. x kota palembang. jurnal kesehatan, 10(1); 105–112 © 2020 the authors. page 47 of 47 introduction experimental section results and discussion conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper particular matter of motor vehicle exposure and high-fat diet effects on kidney histopathology, creatinine, and malondialdehyde (mda) levels in wistar rats rizka veni1,2*, awal prasetyo3, muflihatul muniroh4 1graduate school of biomedicine, faculty of medicine, university of diponegoro, semarang 50275, indonesia 2department of biomedic, faculty of medicine, university of abdurrab, pekanbaru 28291, indonesia 3department of anatomical pathology, faculty of medicine, university of diponegoro, semarang 50275, indonesia 4department of physiology, faculty of medicine, university of diponegoro, semarang 50275, indonesia *corresponding author e-mail: rizkaveni@yahoo.com abstract this study aims to analyze the effect of combination of motor vehicle particular matter exposure and high-fat diet in kidney histopathology, creatinine levels, and mda levels in wistar rats. this study used a posttest-only control group design. eighteen healthy male wistar rats were divided into three groups. the intervention groups received motor vehicle fume exposure for 100 s with normal diet (x1) or high-fat diet (x2), and the control group received no exposure (c). data analysis was processed with a spss 25.0 computer program by using the one-way anova test followed by post hoc lsd. the degree of kidney histopathological damage showed significant differences between the x1 and x2 groups when compared with the control group (p < 0.05). the results of the creatinine level examination found a significant difference between the x2 and c groups (p < 0.05) and the treatment groups x1 and x2 (p < 0.05). the results of kidney mda level examination showed a significant difference between the treatment groups (x1 and x2) and the control group (p < 0.05). the combination of particular matter of motor vehicle fumes exposure and high-fat diet could induce kidney damage through histopathological change and increased creatinine levels and kidney mda levels in wistar rats. keywords creatinine, high-fat diet, histopathological damage, kidney, mda, particular matter received: 4 june 2021, accepted: 21 september 2021 https://doi.org/10.26554/ijems.2021.5.3.124-128 1. introduction ambient air pollution is the biggest environmental health problem in the world, with the greatest toll in the southeast asian regions (who, 2016). in indonesia, the number of motor vehicle increases every year. based on data from the central statistics agency the number of motor vehicles was 85,601,351 in 2011 and increased to 129,281,079 in 2016 (agency, 2017). air pollutants caused a strong impact on health, especially particulate matter (pm), ultrafine particles, ozone (o3), nitrogen dioxide (no2), and sulfur dioxide (so2). one of the main sources of pm is motor vehicle fume (who, 2016). the main components of pm are heavy metals, carbon sources, sulfate, ammonium, nitrate, and various ions (agency, 2017). pm (pm2.5) has been shown to cause an inflammatory response and increase in free radical levels (cho et al., 2018). free radicals cause cell damage, lipid peroxidation, and protein oxidation. the end result of lipid peroxidation is malondialdehyde (mda) (delfino et al., 2011; birben et al., 2012; ozbek, 2012). obesity is also be a problem in the southeast asian regions. the prevalence of obesity ranges from 2% to 10% (who, 2016; hossain et al., 2007). based on riskesdas, the number of obese people in indonesia increases every year. in 2018, the prevalence of obesity in indonesia was 21.8%, which continued to rise since 2007 and 2013 with prevalence of 10.5% and 14.8%, respectively (research, 2013). consumption of a high-fat diet is thought to be the main cause of obesity, which is also known to cause oxidative stress generation (delfino et al., 2011; birben et al., 2012; noeman et al., 2011). the main human organ influenced by toxic substances is the kidney, especially in the glomerular filtrate and through the tubular cells. the impact of these toxic substances results in oxidative stress, which will affect the structure and function of the kidneys (ozbek, 2012). a previous study https://doi.org/10.26554/ijems.2021.5.3.124-128 veni et. al. indonesian journal of environmental management and sustainability, 5 (2021) 124-128 conducted by chen et al. (2018) showed a link between lower estimated glomerular filtration rate (egfr) caused by air pollution, higher prevalence of chronic kidney disease (ckd), and an increased risk of developing ckd in the elderly (chen et al., 2018). in china, gong et al. (2013) also reported increased mda urine and exhaled breath condensate levels during and after the beijing olympics at which time air pollution increased (gong et al., 2013). an experimental study conducted by salim et al. (2018) showed that a high-fat diet promotes obesity and can cause kidney abnormalities as a result of histopathological changes, including dilation, tubular defects, inflammation, and enlargement of the renal connective tissue (salim et al., 2018). in a previous experimental research conducted by noeman et al. (2011) obese rats being given a high-fat diet showed increased levels of mda (noeman et al., 2011). research conducted by wardoyo et al. (2017) on mice exposed to motor vehicle ultrafine smoke particles showed damage to rat organs with the highest severity for the lungs and then kidneys, erythrocytes, and liver (wardoyo et al., 2017). however, there are no in vivo experimental studies that investigate the effects of motor vehicle fumes especially about pm2.5 on the kidney organ. this study aims to analyze the effect of the combination of motor vehicle particular matter exposure and high-fat diet in kidney histopathology, creatinine levels, and mda levels in wistar rats. 2. experimental section 2.1 motor vehicle samples pm2.5 describes fine inhalable particles, with diameters that are generally 2.5 µm and smaller. in this research, motor vehicle fumes come from the exhaust of a 125-cc automatic motorbike fueled by pertalite output in 2017. the concentration of the number of smoke particles with a diameter of ≤ 2.5 µm was measured using kanomax model 3443. 2.2 motor vehicle fumes exposure motor vehicle fumes are exposed by placing the test animals in closed cages that have been given holes for fumes and for ventilation. the motor is started, and then the smoke is collected in the reservoir and connected to the cage with ventilation (figure 1). 2.3 experimental animals animal management tries to follow “animal ethics”. this research was submitted to and approved by the ethics commission for medical/health research, faculty of medicine, sultan agung islamic university, semarang, with a certificate no. 282/viii/2020/bioethics commission dated august 30, 2020. eighteen healthy male wistar rats were used in this study. they were acclimatized for 3 days in a fumigation chamber measuring 77 × 52 × 35 cm with room temperature ranging from 25°c to 28°c and room humidity levels ranging from 70% to 75%. light reception is set to figure 1. the smoke procedure (modified) (wardoyo et al., 2017) 12-h bright/dark cycle. after acclimatization, the experimental animals were randomly divided into three groups. the intervention groups received motor vehicle fume exposure for 100 s with normal diet (x1) or high-fat diet (x2), and the control group did not get any exposure (c). rats were given pellet type ad ii, high-fat feed, and reverse osmosis drinking water, which were given ad libitum. on the fourth day, weight measurements were taken. body weight was weighed using the mettler toledo digital scale with an accuracy level of 0.1 g. after a 28-day treatment period, a surgical sampling of kidney tissue was carried out. previously, the rats were anesthetized by giving a ketamine injection of 60 mg/kgbw (i.m.). 2.4 histopathological analysis the obtained kidney tissue is then fixed with a 10% neutral buffer formalin solution and left at room temperature for 48 h. furthermore, histological preparations were made, and h&e staining was done according to the procedure. cell damage is observed, which includes widening of the tubular lumen and necrotic cells. each of these parameters was graded as follows: 0, no damage; 1, slight (25%); 2, moderate (50%) and marked (75%). the prepared kidney histopathology was observed in eight fields of view under a microscope with a 400× magnification. observations were made by two observers with the double blind methods. 2.5 statistical analysis all the obtained data were processed with a spss 25.0 computer program and analyzed using one-way anova test followed by post hoc lsd. there was a significant difference if p < 0.05. 3. results and discussion 3.1 result 3.1.1 degree of kidney damage table 1 presents the results of examining the degree of kidney damage at the end of treatment. the negative and light degree of kidney damage were only in the c group. the x1 group that received motor vehicle fume exposure for 100 s with normal diet had various © 2021 the authors. page 125 of 128 veni et. al. indonesian journal of environmental management and sustainability, 5 (2021) 124-128 table 1. the degree of kidney damage among treatment group group degree of kidney damage sig negative + ++ +++ total x1 x2 c 4 2 0 0 6 0.000* 0.000* x1 0 1 4 1 6 0.056 x2 0 0 2 4 6 c = the control group did not get any exposure, x1 = the intervention group received motor vehicle fume exposure for 100 s with normal diet, x2 = the intervention group received motor vehicle fume exposure for 100 s with high-fat diet. analysis was done using one-way anova test. *significant difference p < 0.05. degrees of kidney damage, that is, one in slight degree, four in moderate degree, and one in marked degree. in the x2 group that received motor vehicle fume exposure for 100 s with high-fat diet, two were in moderate degree, and four were in marked degree of kidney damage (table 1; figure 2). figure 2. histopathology features of rats’ kidney tissue in control group (a), the x1 group that received motor vehicle fume exposure for 100 s with normal diet (b), and the x2 group that received motor vehicle fume for 100 s with high-fat diet (c). the white arrows showed edema tubules of the kidney. the one-way anova test results showed that there was a significant difference in kidney histopathological damage (p < 0.05). furthermore, the post hoc lsd test was conducted to determine which groups had significant differences. 3.1.2 creatinine and mda levels results table 2 presents the results of checking creatinine and mda levels at the end of treatment. as presented in table 2, the highest creatinine and mda level was found in the intervention group that received motor vehicle fume exposure for 100 s with high-fat diet (x2) compared to the control and x1 group. creatinine and mda level increased two times in the x2 group compared with the control. furthermore, one-way anova test results showed that there was a significant difference in the increase in creatinine levels (p < 0.05) and mda levels. 3.2 discussion this study showed that kidney histopathological damage showed significant differences between the x1 and x2 groups when compared with the control group (p < 0.05). the highest result was found in the x2 group (table 1). this kidney damage is caused by the pollutants produced by motorized vehicles containing the dangerous substance, namely, particulate matter, which causes oxidative stress. moreover, the combination of particulate matter exposure with highfat diet will cause oxidative stress generation, and oxidative stress increases free radical levels. free radical will cause cell damage in the kidney (delfino et al., 2011; birben et al., 2012; ozbek, 2012; hanifah, 2008). the results of this study are in line with the previous study conducted by wardoyo et al. (2017) in which exposure to ultrafine particles of motor vehicle fumes resulted in damage to the organs of mice with the highest severity for the lungs, followed by kidneys, erythrocytes, and liver (wardoyo et al., 2017). in addition, research by salim et al. (2018) showed that high-fat diet triggers obesity and can cause abnormalities in the kidneys as a result of histopathological changes such as dilation, tubular defects, inflammation, and enlargement of the kidney connective tissue (salim et al., 2018). a decrease in glomerular filtration rate (gfr) indicates kidney damage by counting the amount of filtrate produced by the glomerulus (simon et al., 2011; van bladel et al., 2012). to estimate the gfr of elfg based on the formula from the chronic kidney disease epidemiology collaboration (elfgckd-epi) (michels et al., 2010). elfg ckdepi has better accuracy and uses four variables, namely serum creatinine levels, age, sex, and race (who, 2016; ning et al., 2018). the results of the creatinine level examination showed an increase in creatinine levels after exposure to motor vehicle fumes for 100 s/day for 28 days, and the highest increase in creatinine levels was found on the x2 group © 2021 the authors. page 126 of 128 veni et. al. indonesian journal of environmental management and sustainability, 5 (2021) 124-128 table 2. results of the creatinine and mda level examination group creatinine levels mda levels mean ± sd sig mean ± sd sig x1 x2 x1 x2 c 0.3000 ± 0.08944 0.261 0.001* 187.2593 ± 47.81480 0.007* 0.000* x1 0.3667 ± 0.13663 0.011* 261.7037 ± 42.26703 0.000* x2 0.5333 ± 0.05164 381.7037 ± 30.87743 c = the control group did not get any exposure, x1 = the intervention group received motor vehicle fume exposure for 100 s with normal diet, x2 = the intervention group received motor vehicle fume exposure for 100 s with high-fat diet. analysis was done using one-way anova test. *significant difference p < 0.05. (table 2). the results of the creatinine level examination found a significant difference between the x2 and c groups (p < 0.05) and the treatment groups x1 and x2 (p < 0.05). the increase in serum creatinine levels due to pm2.5 exposure is in accordance with the research conducted by ning et al. (2018) in which exposure to pm2.5 directly or indirectly increases levels of creatinine, citric acid, succinic acid, malic acid, and maltose, affecting metabolic changes in the hippocampus area (ning et al., 2018). furthermore, the results of kidney mda level examination showed a significant difference between the treatment groups (x1 and x2) and the control group (p < 0.05). particulate matter contained in motor vehicle fumes and a high-fat diet cause an inflammatory response and the formation of free radicals, resulting in cell damage, lipid peroxidation, and protein oxidation. the end result of lipid peroxidation is malondialdehyde (mda) (delfino et al., 2011; birben et al., 2012; ozbek, 2012). the results of this study are in line with the previous experimental research conducted by noeman et al. (2011) which showed that obesity induced by a high-fat diet is accompanied by an increase in oxidative tissue of the liver, heart, and kidneys, characterized by a reduction in antioxidant enzyme activity and glutathione levels, correlated with increased levels of mda and protein carbonyl (pco) in most tissues (noeman et al., 2011). 4. conclusions from the results of the study, it was found that the combination of particulate matter from motor vehicle fume exposure and high-fat diet could induce kidney damage by histopathological change and increased creatinine levels and kidney mda levels in wistar rats. 5. acknowledgement this study was supported by department of biomedic, faculty of medicine diponegoro university and abdurrab university references agency, c. s. 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(2018). the effects of high-fat diet on histological changes of kidneys in rats. biomolecular and health science journal, 1(2); 109–112 simon, j., m. amde, and e. d. poggio (2011). interpreting the estimated glomerular filtration rate in primary care: benefits and pitfalls. cleveland clinic journal of medicine, 78(3); 189–195 van bladel, e. r., r. l. de jager, d. walter, l. cornelissen, c. a. gaillard, l. a. boven, m. roest, and r. fijnheer (2012). platelets of patients with chronic kidney disease demonstrate deficient platelet reactivity in vitro. bmc nephrology, 13(1); 1–6 wardoyo, a. y., u. p. juswono, and j. a. noor (2017). an observation of histological evidence on internal organ damages in mice caused by repeated exposures to motorcycle emissions. aip conference proceedings, 1844(1); 020007 who (2016). ambient air pollution: a global assessment of exposure and burden of disease © 2021 the authors. page 128 of 128 introduction experimental section motor vehicle samples motor vehicle fumes exposure experimental animals histopathological analysis statistical analysis results and discussion result degree of kidney damage creatinine and mda levels results discussion conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper alternative scenarios to utilise excess biogas in palm oil mill novelita wahyu mondamina1*, deni rachmat1, mochammad waris tegar laksono1 11palm oil processing technology, vocational faculty, institut teknologi sains bandung, cikarang, 17530, indonesia *corresponding author e-mail: novelita@itsb.ac.id abstract palm oil mill is a factory which converts fresh fruit bunch (ffb) to crude palm oil (cpo) and palm kernel oil (pko). within ffb converting processes, two types of waste are produced: 1)liquid waste and 2)solid waste. liquid waste, named palm oil mill effluent (pome), contributes up to 60% of total ffb. solid waste includes palm kernel shell and meal, fibre and empty fruit bunch gives in aggregate around 20% of total ffb. initially, palm kernel shell (pks) is commonly utilised as fuel for boiler. then in some mills, pome was additionally used as biomass for biofuel production (biogas) to support power supply in the mill. biogas is utilised to generate electricity for kernel crushing plant (kcp). field observation data shows that electricity demand for kcp is 19.5 mwh/day or equivalent with 45% of total biogas production. the excess biogas, equivalent with 11,000 kwh/day, is flared. an alternative scenario instead of flaring is to use biogas as fuel for boiler. thus, the previous fuel (pks) could potentially be allocated for selling. another scenario is to utilise excess biogas electricity generation to be distributed to staff houses near the mill. therefore, this research study aims to calculate excess biogas that could be used for those scenarios: 1)fuel substitution in the mill with different type of process, 2)household electricity. result shows that biogas demand in each scenario can supply 1) minimum 2,900 kwh/day for non-processing hours and 6,436.65 kwh/day for processing hours, 2) electricity for 557 houses/day. keywords biogas, flaring, pome, electricity, waste management received: 3 june 2020, accepted: 20 june 2020 https://doi.org/10.26554/ijems.2020.4.2.48-54 1. introduction indonesia is globally known as palm oil producer together with malaysia. in 2019, indonesia is seen that cpo production has escalated 9% compared to 2018, reaching 51.8 million tonnes (gapki, 2020). on the other side, an increasing production for both cpo and pko also causes higher amount of waste output. palm oil waste contributes around 75% of total processed ffb in the mill within 1 batch of cpo production (hambali and rivai, 2017). in general, palm oil waste can be classified into 2 groups: 1) solid waste which covers empty fruit bunch, fibres and palm kernel shell, and 2) liquid waste, pome. palm oil waste treatment is currently being carried out in the mill to improve its added value and reduce waste disposal in open pond. for example, using pome as biomass for biogas production (rajani et al., 2019). palm kernel shells and fibres are used as boiler fuel. empty fruit bunches are used as composting material (singh et al., 2010). however, high amount of palm oil waste requires a more efforts and different plans so that all waste can be optimally utilised. some palm oil mills in indonesia have already installed biogas plant and applied it to support ffb processing activities. for example, biogas is used as fuel for gas engine to generate electricity. the electricity is then delivered to kcp. however, some other mills have installed biogas plant with minimum end use. they flare the biogas due to incompatibility engines in mill to be integrated with biogas (rahayu et al., 2015). this study aims to provide alternative scenarios promoting the use of excess biogas, minimising biogas to be flared. in this case, excess biogas means certain amount of biofuel which no longer be used to bolster cpo or pko production in mill. when biogas is surplus, flaring usually becomes as a solution because excess biogas cannot economically be stored or used. flaring could rise the formation of undesirable combustion products such as carbon monoxide (co), partially oxidised hydrocarbon, nox, dioxins and furans (miller, 2016). furthermore, flaring could also potentially lead to odor nuisance, visual and noise impact. flaring could serve as a large loss of energy capacity or valuable products, as well as a contribution to global warming (thurber, 2019). there are 2 scenarios that will be covered in the analysis. https://doi.org/10.26554/ijems.2020.4.2.48-54 mondamina et. al. indonesian journal of environmental management and sustainability, 4 (2020) 48-54 table 1. the properties of pome. source: (rahayu et al., 2015) parameter unit pome without parameter processing standard range* average water land bodies** application bod mg/l 8,200 – 35,000 21,280 100 5,000 cod mg/l 15,103 – 65,100 34,740 350 tss mg/l 1,330 – 50,700 31,170 250 ammonia (nh3-n) mg/l 12 – 126 41 50*** oil and fat mg/l 190 – 14,720 3,075 25 ph 3.3 – 4.6 4 6 – 9 6 – 9 max pome m3/ton 2.5 produced cpo *source pertanian (2016) ** source hidup (2010) *** total nitrogen = organic nitrogen + total ammonia + no3 + no2 each scenario will mainly consider the amount of biogas demand if it would be allocated as: 1)old-fuel substitution in mill for boiler, and 2)mains electricity in staff houses. 1.1. palm oil mill effluent (pome) as biomass pome is one of the palm oil waste which has been produced during oil extraction from ffb. pome counts for nearly 75% of total processed ffbs (figure 1). based on its properties (see table 1), pome has a potential to be utilised as biomass. previously, pome was placed in open pond before it was used as fertiliser for oil palm plantation. putting pome in open pond had risk to naturally release methane gas ch4 to the atmosphere. as a consequence, the risk of global warming will increase (enström et al., 2019). according to its calorific value, methane has a similar characterisation with fossil fuel (pertiwiningrum et al., 2018). therefore in the last 5 years, some palm oil mills in indonesia has started to feed pome into closed pond, named anaerobic digester to hold ch4. methane gas or ch4 is commonly known as biogas (rahayu et al., 2015). in indonesia, two types of anaerobic digester are used: covered lagoon and continuous stirrer tank reactor (cstr). when pome starts to produce biogas in the digester, it contains 50 – 75% ch4, 25 – 45% co2 and other trace gases (poh and chong, 2009). biogas has calorific value 20 mj/nm3 or equivalent with around 6 kwh electricity (center, 2012). using biogas as fuel will lead to independent power generation in the mill. moreover, utilising biomass is also seen as a contribution to tackle climate change. 1.2. electricity demand of palm oil mill electricity usage in palm oil mill is generally allocated for two business activities: 1) cpo production and 2) pko production in kcp. general parameter of electricity consumption in palm oil mill is between 17 kwh/ ton ffb figure 1. pome production in palm oil mill. source of pome generally comes from sterilisation condensate, sludge separator and hydro cyclone. adapted from (jayakumar et al., 2017). and 19 kwh/ ton ffb (b, 2012). in cpo production, electricity is distributed in two different periods namely non-processing hours and processing hours. non-processing hours means that ffbs are not being processed for cpo extraction. thus, processing hours starts to count when ffbs are processed. either processing or non-processing hours can take around 9 up until 15 hours per day, alternately. electricity demand relies on production capacity of the mill which varies between 30, 45 and 60 tonnes ffb/ day, whilst kcp production capacity for pko typically either 7.5, 10 or 21 tonnes palm kernel/ day. operational hours for kcp is approximately 22 hours/ day (yuliansyah et al., 2009). © 2020 the authors. page 49 of 54 mondamina et. al. indonesian journal of environmental management and sustainability, 4 (2020) 48-54 2. experimental section 2.1. materials biogas monthly data was recorded and used as primary data for further calculation and analysis. research flowchart of this study can be seen in the figure 2. the research was conducted between january and april 2018 in a palm oil mill which has biogas plant installation. the capacity production of the mill is 60 tonnes of ffb/ hour. the mill also has kcp with 7.5 tonnes of palm kernel/ hour capacity production. biogas plant is located near the mill and produces around 23,300 m3 biogas every day. biogas was produced within anaerobic process by using continuous stirred tank reactor (cstr) with average efficiency around 79% per month. the mill has 2 digester tanks with total volume of 9,110 m3. the temperature of anaerobic digestion was in mesophilic condition, 37 0c. the electricity demand for mill is referred to typical power consumption of 60 tonnes of ffb/ hour production capacity with 2 operational lines (parinduri, 2018). on the other hand, electricity demand for house is identified by interviewing staff who works and lives close to palm oil mill. figure 2. research flowchart 2.2. methods recorded biogas data is mainly used for analysis and scenario development. each scenario is measured based in the excess amount of biogas (m3). the electricity generation is calculated by using conversion factor, 3.4 kw/m3 ch4, based on key performance indicator (kpi) of the mill. in general, biogas engines for electricity generation from 100 kwel and 1 mwel have efficiency range between 34% and table 2. operational hours in a day in palm oil mill. source: author’s documentation no. day operational hours in a day processing non-processing hours hours 1 monday 12.9 9.1 2 tuesday 14.51 9.49 3 wednesday 11.77 12.23 4 thursday 15.1 8.9 5 friday 8.95 15.05 6 saturday 7.05 14.95 40% (benato et al., 2017). in this study, 40% is used as efficiency number for calculation in each scenario. electricity demand per day is estimated by using typical usage of power consumption in palm oil mill, both for nonprocessing and processing hours (see table 3). similar approach is also implemented for household electricity of staff houses near the mill. power consumption of staff houses is obtained by interviewing staff who lives close to the mill. standard electronic appliances are available in the house. the period of usage is assumed by typical work and stay-at-home hours of mill staffs (table 4). 3. results and discussion the calculated average potential energy of pome in the mill is 43,380 kwh per day. the clean fuel product was firstly delivered to kcp which required around 19,540 kwh/day or equivalent with 45% of total potential energy of pome (equation 1). the average excess amount of biogas and its power generation from january until april 2018 are summarised in table 5. the calculated electricity from excess biogas is then allocated to different scenarios to see alternative ways of utilising the renewable fuel besides flaring. power demand for kcp(%)= averagebiogasconsumption averageeoofpome x 100% power demand for kcp(%)= 19,540 kwh day 43,380 kwh day x 100 % power demand for kcp(%)= 45% 3.1. 1st scenario: excess biogas for non-processing and/ or processing hours first scenario is to allocate excess biogas for non-processing and/ or processing hours activities in cpo station production. according to table 5, excess biogas is equivalent with around 11,000 kwh per day. the total measured electricity for each day of non-processing hours is summarised in table 6. electricity demand for non-processing hours is around 2,900 kwh until 5,000 kwh per day. if the excess biogas is only allocated for non-processing hours, there will be between 55% and 74% of total excess biogas left to be © 2020 the authors. page 50 of 54 mondamina et. al. indonesian journal of environmental management and sustainability, 4 (2020) 48-54 table 3. typical usage of electricity consumption in palm oil mill cpo capacity production 60 tonnes of ffb/ hour with 2 operational lines. source: (parinduri, 2018) no station actual power per hour processing nonhour processing hour kw kw 1 reception & 13 13 steriliser 2 thresher 50 3 pressing 68 line 1 4 pressing 74 line 2 5 clarification 105 6 oil storage 6 7 kernel line 1 158 8 kernel line 2 118 9 boiler 158 158 control 10 water 66 66 treatment plant 11 boiler 29 29 demineralisation 12 effluent 21 21 treatment 13 factory 26 26 lighting 14 domestic 21 21 lighting total (kw per hour) 913 334 flared. in another case, if excess biogas is only delivered to fulfil operational activities of processing hours, it is quite in risk because some operational days will require more power supply (table 6). another alternative is to use all excess biogas for both non-processing and processing hours, with first priority to fulfil processing hours then the remaining biogas is used to support non-processing hours. based on electricity demand calculation for both processes, total demand will be varying between 10,000 kwh and 16,000 kwh per day. all excess biogas will not be enough to support both processes. additional power supply is required (figure 3). this issue could alternatively be tackled by supplying electricity from boiler. therefore, flaring will not be needed because all biogas has been utilised. 3.2. 2nd scenario: excess biogas for staff households second scenario is to distribute excess biogas to electrify staff houses near palm oil mill. according to table 4, a figure 3. power consumption in non-processing and processing hours and amount of additional power supply staff house needs around 20 kwh per day. the excess biogas on daily basis is around 11,000 kwh. therefore, if all electricity generation from excess biogas is delivered to staff houses, there will be about 557 houses are electrified. this alternative scenario is considered because the mill actually has surplus biomass supply to generate power. as mentioned earlier, during cpo production, palm oil mill also produces solid waste, such as palm kernel shell and fibre. these biomass then are used as fuel in boiler to generate electricity (figure 1). thus, rather than using all biomass for only internal usage in the mill, some of them could also alternatively be used to electrify surrounded house communities. typical power consumption for a day in a staff house is in figure 4. it can be seen that peak hours rise between 05:00 and 06:00 also 16:00 and 17:00. these hours are representative as staffs are going to mill in the morning and back to their house in the evening. refrigerator and ac ½ pk have highest percentage of power demand, consuming 37% and 35% of total supplied power, respectively. each of the remaining electrical appliances only consumes less than 10% of total supplied power. figure 4. typical power usage in a staff house 4. conclusions instead of flaring, there are some alternative ways to optimise the usage of excess biogas. biogas is considered as clean fuel that can substitute fossil fuel combustion, which then lead to less carbon emission. excess biogas in the palm oil mill is equivalent with around 11,000 kwh per day. © 2020 the authors. page 51 of 54 mondamina et. al. indonesian journal of environmental management and sustainability, 4 (2020) 48-54 table 4. power usage of standard electronic appliances in staff house between 00.00 – 12.00 and 13.00 – 23.00 hours. source: author’s documentation no power (watt) usage period 0 1 2 3 4 5 6 7 8 9 10 11 1 ac 1/2 pk 400 400 400 400 400 400 400 2 tv 32” 50 50 3 refrigerator 300 300 300 300 300 300 300 300 300 300 300 300 4 laundry 350 350 machine 5 rice cooker 350 50 50 50 50 50 50 6 steam/ 350 350 dry iron 7 water 6 6 6 6 6 250 250 6 6 6 6 6 dispenser 8 ceiling fan 9 led lamps 70 70 70 70 70 70 total power 776 776 776 776 776 1420 1050 356 356 1056 1056 356 (w/hour) no power (watt) usage period 12 13 14 15 16 17 18 19 20 21 22 23 1 ac 1/2 pk 400 400 400 400 400 400 400 400 400 400 2 tv 32” 50 50 50 50 50 50 50 50 3 refrigerator 300 300 300 300 300 300 300 300 300 300 300 300 4 laundry machine 5 rice cooker 50 50 50 50 50 350 50 50 50 50 6 steam/ dry iron 7 water 6 6 6 6 6 250 250 6 6 6 6 6 dispenser 8 ceiling fan 75 75 75 75 75 9 led lamps 70 70 70 70 70 70 total power 881 881 756 356 356 1425 1195 951 876 876 826 776 (w/hour) total power 20per day (kwh/ day) total power 591for 30 days (kwh) © 2020 the authors. page 52 of 54 mondamina et. al. indonesian journal of environmental management and sustainability, 4 (2020) 48-54 table 5. excess amount of biogas and its power generation. source: author’s documentation month average average potential flare feeding excess to electricity calculated pome biogas generation* electricity** (m3/ day) to flare (kw/m3 (kw/day) (m3/ day) ch4/ day) jan-18 396 7,921 26,931 10,773 feb-18 342 7,897 26,851 10,740 mar-18 349 8,412 28,601 11,440 apr-18 342 7,997 27,189 10,876 average 357 8,057 27,393 10,957 table 6. power consumption of process power power consumption consumption in in operational nonprocessing day processing hour hour (kwh/ day) (kwh/ day) monday 3,039.40 11,777.70 tuesday 3,169.66 13,247.63 wednesday 4,084.82 10,746.01 thursday 2,972.60 13,786.30 friday 5,026.70 8,171.35 saturday 4,993.30 6,436.65 there are 2 alternative scenarios to minimise biogas flaring. first scenario is to distribute excess biogas as biofuel for electricity generation in non-processing and/ or processing hours in the mill. if power generation from excess biogas is only allocated for non-processing hours, then up to 5,000 kwh per day is required, leaving 55% to be flared. if power generation is only distributed for processing hours, all excess biogas could potentially be used. however, further observation is required as there will be some operational days that need additional power supply. if excess biogas is intended to be allocated for both non-processing and processing hours, extra power generation such as from boiler is definitely needed. alternatively, in the second scenario, excess biogas could also be used to electrify staff houses who live near the mill. around 557 houses are electrified. references b, r. i. (2012). identifikasi konsumsi energi listrik di pabrik kelapa sawit benato, a., a. macor, and a. rossetti (2017). biogas engine emissions: standards and on-site measurements. energy procedia, 126; 398–405 center, s. g. (2012). basic data on biogas. swedish gas technology centre enström, a., t. haatainen, a. suharto, m. giebels, and k. y. lee (2019). introducing a new ghg emission calculation approach for alternative methane reduction measures in the wastewater treatment of a palm oil mill. environment, development and sustainability, 21(6); 3065– 3076 gapki (2020). refleksi industri kelapa sawit 2019 dan prospek 2020. indonesian palm oil association (gapki ipoa) hambali, e. and m. rivai (2017). the potential of palm oil waste biomass in indonesia in 2020 and 2030. iop conference series: earth and environmental science, 65; 012050 hidup, m. n. l. (2010). keputusan mentri negara lingkungan hidup no. 3/2010 tentang baku mutu air limbah bagi kawasan industri jayakumar, s., m. m. yusoff, m. h. a. rahim, g. p. maniam, and n. govindan (2017). the prospect of microalgal biodiesel using agro-industrial and industrial wastes in malaysia. renewable and sustainable energy reviews, 72; 33–47 miller, v. (2016). why we flare parinduri, l. (2018). analisa pemanfaatan pome untuk sumber pembangkit listrik tenaga biogas di pabrik kelapa sawit. jet (journal of electrical technology), 3(3); 180–183 pertanian, d. (2016). pedoman pengelolaan limbah industri sawit pertiwiningrum, a., a. w. harto, m. a. wuri, r. budiarto, et al. (2018). assessment of calorific value of biogas after carbon dioxide adsorption process using natural zeolite and biochar. international journal of environmental science and development, 9(11); 327–330 poh, p. and m. chong (2009). development of anaerobic digestion methods for palm oil mill effluent (pome) treatment. bioresource technology, 100(1); 1–9 rahayu, a., d. karsiwulan, h. yuwono, i. trisnawati, s. mulyasari, s. rahardjo, s. hokermin, and v. paramita © 2020 the authors. page 53 of 54 mondamina et. al. indonesian journal of environmental management and sustainability, 4 (2020) 48-54 (2015). handbook pome-to-biogas project development in indonesia. winrock international, united states of america; 8–19 rajani, a., a. santosa, a. saepudin, s. gobikrishnan, d. andriani, et al. (2019). review on biogas from palm oil mill effluent (pome): challenges and opportunities in indonesia. in iop conference series: earth and environmental science, volume 293. iop publishing, page 012004 singh, r., m. h. ibrahim, n. esa, and m. iliyana (2010). composting of waste from palm oil mill: a sustainable waste management practice. reviews in environmental science and bio/technology, 9(4); 331–344 thurber, m. (2019). gas flaring: why does it happen and what can stop it? energy for growth yuliansyah, a. t., t. hirajima, et al. (2009). development of the indonesian palm oil industry and utilization of solid waste. journal of mmij, 125(12); 583–589 © 2020 the authors. page 54 of 54 introduction experimental section results and discussion conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper effects of spirulina platensis extract on serum malondialdehyde (mda) levels and differential leukocyte count on motor vehicle exhaust emissions exposure (in vivo study on wistar rats) dea may fitry 1*, nani maharani 2, renni yuniati 3 1graduate school of biomedicine, faculty of medicine, university of diponegoro, semarang, indonesia 2department of pharmacology and therapy, faculty of medicine, diponegoro university, semarang, indonesia 3department of dermatovenerology, faculty of medicine, diponegoro university , semarang, indonesia *corresponding author e-mail: deamfitry@gmail.com abstract the particulate matter in vehicle emission has been shown to cause an increase in free radical levels which can increase serum mda levels and leukocyte count. spirulina platensis is an algae that has antioxidant effects that can scavenge free radicals. in this research, twenty-four of wistar mice are divided into 4 groups. groups x1 and x2 received vehicle emission smoke exposure treatment and were given oral spirulina platensis extract at a dose of 500 and 750 mg / kgbw / day for 14 days, the negative control group (c2) was given 0.9% nacl orally and the normal control group did not get vehicle emission smoke exposure and spirulina platensis extract. serum mda levels were checked by elisa method and leukocyte count by giemsa staining. data analysis was performed by using the one-way anova test followed by post hoc bonferroni. the results showed the mean serum mda levels there was a significant difference between group c2 and group x2. in the mean absolute value of neutrophils and lymphocytes, there were significant differences between the c2 group with the administration of x1 and x2. in the mean absolute value of eosinophils and monocytes, there were significant differences between groups c1 and c2 and group x2 and between groups x1 and c1. furthermore, the given doses of spirulina platensis extract at a dose of 750mg / kgbw had an effect on serum mda levels as well as the number of neutrophils and lymphocytes and the administration of doses of 500 and 750mg / kgbw affected the number of eosinophils and monocytes. keywords spirulina platensis, pm2.5, mda, leukosit received: 8 september 2020, accepted: 28 september 2020 https://doi.org/10.26554/ijems.2020.4.3.85-89 1. introduction ambient air pollution (outdoor air) is the biggest world problem of environmental health. according to who, there were an estimated 4.2 million deaths in 2016 due to ambient air pollution. adverse health effects can occur as a result of short or long-term exposure. the main effect of ambient air pollutants is particulate matter (pm), ozone (o3), nitrogen dioxide (no2) and sulfur dioxide (so2). one of the main sources of pm is vehicle emission from diesel and gasoline (who, 2016). the presents of free radicals and the inflammatory response of ambient air pollution can cause several health problems (lu et al., 2018; manzetti and andersen, 2016; gong et al., 2013; lee et al., 2018). free radicals will cause cell damage, lipid peroxidation and protein oxidation. the result of lipid peroxidation is malondialdehyde (mda)(birben et al., 2012). the inflammation that occurs in the short term can increase the risk of exacerbation of several diseases such as copd, asthma and autoimmune diseases and in the long term can cause various cardiorespiratory diseases. one marker of inflammation is leukocytes (lee et al., 2018). as similarly reported by gong et al. (2013) in china, showed the increasing mda urine percentage and exhaled breath condensate (ebc) during the beijing olympics in which air pollution was increased dramatically. according to yan et al. (2017) showed an increase in mda d levels in mice with were given exposure to pm 2.5 (particles <2.52µm in size) compared to control rats. lee et al. (2018) also reported that in 2010 to 2016 showed an increase in the number of leukocytes due to long-term exposure to ambient air pollution in south korea. however, indonesian marine biota has a huge opportunity to be explored as a source of natural antioxidant compounds. one of the microorganisms https://doi.org/10.26554/ijems.2020.4.3.85-89 fitry et. al. indonesian journal of environmental management and sustainability, 4 (2020) 85-89 that have the potential as a source of natural antioxidants is spirulina platensis (yudiati et al., 2011). spirulina platensis is a filamentous and multicellular blue-green alga capable of reducing inflammation and also manifesting antioxidant effects. spirulina platesis is a natural source of protein, vitamins, macronutrients and micronutrients such as amino acids, gamma linoleic acid, chlorophyll and phycocyanin (abd el-hakim et al., 2018) previous studies have shown the antioxidant potential of spirulina platensis. el-baz et al. (2013)conducted a study which showed that spirulina platensis extract had a beneficial effect in controlling hyperglycemia and reducing mda levels in streptozoticin-induced dm type 2 rats (stz). in addition, research conducted by al-qahtani and binobead (2019) spirulina platensis is produced in different areas. in this research, the antioxidant potential possessed by spirulina platensis is expected to inhibit lipid peroxidation and inflammation which can be measured by seeing a decrease in mda levels. 2. experimental section 2.1 spirulina platensis extract this study used spirulina platensis powder with the registration number fda 15594742028 and ceres number 50oga1200043 (9241). spirulina platensis powder was extracted by maceration (immersion), with a ratio of 1:10, namely 1 part of the spirulina platensis microalgae sample powder soaked in 10 parts of 95% ethanol solution. maceration is carried out for 5 days in a glass container. shake the glass container every day for a few minutes. after 5 days the solution was filtered with whatman filter paper. the next step is evaporation using a rotary evaporator at the boiling temperature of ethanol until a concentrated extract is obtained. 2.2 vehicle emission and exposure setting system the vehicle emission carried out by comes from a 125 cc automatic motorcycle was product in 2017 and fueled by pertalite. the exposure was carried out by setting the system i.e., the exhaust is connected to the sucking pump, where only particles less than 2.5µm in diameter can pass (using whatman filter paper no 42). the sucking pump will flow the smoke into the exposure chamber. then the motorcycle engine is operated for 80 seconds. the pm2.5 concentration in the exposure chamber was measured using a kanomax (figure 1). the inhalation time of pm2.5 per day per 80 seconds of fumigation is 100 seconds where the pm2.5 dose exposed to mice is 0.625 + 0.069mg/m3. 2.3 procedure of wistar mice exposure twenty-four male wistar mice aged 2-3 months with a weight of 100-200gr were acclimatized for 7 days with room temperatures ranging from 25-28oc and room humidity levels ranging from 70-75%. a light reception is set to 12 hours bright and 12 hours dark. rats were given feed in the figure 1. procedure for exposure to vehicle emission (note: 1 = motorcycle exhaust; 2 = sucking pump + filter paper; 3 = exposure chamber; 4 = kanomax; 5 = connecting pipe) form of ad ii pellets and reverse osmosis drinking water which was given ad libitum. on the 8th day, twenty-four male wistar rats that had met the inclusion criteria were then divided into 4 groups randomly (randomization) where each group consisted of 6 wistar rats. groups x1 and x2 received vehicle emission exposure treatment and were given oral spirulina platensis extract at a dose of 500 and 750 mg/kgbw/day, the negative control group (c2) was given exposure to smoke and nacl 0.9% orally and the normal control group did not get vehicle emission exposure and spirulina platensis extract. after fourteen-day treatment, the wistar rats were anesthetized by giving ketamine injection at a dose of 60 mg/kgbw (i.m). then two separate blood samples were taken from the retroorbital veins of each mouse. the first sample was used for examination of serum mda levels by the elisa (enzyme linked immunosorbent assay) method according to the protocol specified in the commercial kit used (catalog no: e-el-0060: elab science biotechnology, texas, usa). the second sample was used for manual examination of leucocyte count with giemsa staining according to the procedure. this research has been approved by the medical / health research bioethics commission, faculty of medicine, sultan agung islamic university, semarang with the ethical clearance number 521 / viii / 2019 / bioethics commission. 2.4 statistical analysis using anova the statistical analysis of this study used the spss 25 computer program. the test performed was one-way anova and was further analyzed by post hoc bonferroni. the significance value in this study was p<0.05. 3. results and discussion 3.1 serum mda levels the results after measuring serum mda levels using the elisa method, the measurement results are obtained as presented in table 1. the results of the one-way anova analysis on serum mda levels showed significant differences between the study groups and then further analyzed using the bonferroni post © 2020 the authors. page 86 of 89 fitry et. al. indonesian journal of environmental management and sustainability, 4 (2020) 85-89 table 1. results of measurement of serum mda levels (ng / ml) groups mean+sd min-max p* c1 195.0+22.15 163.56 – 220.22 p<0.001 c2 376.1+55.57 293.56 – 441.33 x1 326.7+44.51 280.22 – 392.44 x2 178.6+25.22 155.78 – 209.11 hoc test. the results of the post hoc test showed that there was a significant difference between the negative control group (c2) and the group giving spirulina platensis extract 750mg/kgbw (x2) and between the two control groups (c1 and c2). 3.2 differential leukocyte counts the value of absolute neutrophil and lymphocyte count, the results are shown in table 2 and table 3. the results table 2. the value of absolute neutrophil (x103/ µl) groups mean+sd min-max p* c1 4.7+2.07 3-8 p<0.001 c2 12.8+3.49 9-18 x1 4.0+1.52 2-6 x2 4.7+2.13 2-8 table 3. the value of absolute lymphocyte (x103/ µl) groups mean+sd min-max p* c1 4.3+2.07 2-7 p<0.001 c2 11.8+5.27 3-19 x1 5.3+2.50 2-9 x2 3.8+1.94 1-6 of the one-way anova analysis on the value of absolute neutrophil and lymphocyte count showed that there were significant differences between the study groups and then further analyzed using the post hoc bonferroni test. the results of the post hoc test showed that there was a significant difference between the negative control group (c2) and the group giving spirulina platensis extract 500mg/kgbb (x1) and 750mg/kgbb (x2) and between the two control groups (c1 and c2). thus, the results of the one-way anova analysis on the value of absolute eosinophils (table 4) and monocytes (table 5) showed that there were significant differences between the study groups and were further analyzed using the post hoc bonferroni test. the results of the post hoc test showed that there was a significant difference between the two control groups (c1 and c2) with the group giving spirulina platensis extract 750mg / kgbb (x2) and between the group giving spirulina platensis extract 500mg / kgbb (x1) and the normal control (c1). table 4. the value of absolute eosinophils (x103/ µl) groups mean+sd min-max p* c1 1.8+1.17 0-3 p<0.001 c2 8.5+1.87 6-11 x1 7.4+2.12 5-10 x2 5.1+0.98 4-6 table 5. the value of absolute monocytes (x103/ µl) groups mean+sd min-max p* c1 1.7+1.21 0-3 p<0.001 c2 10.3+2.16 8-14 x1 10.4+2.26 7-13 x2 5.1+1.91 3-8 the spirulina platens is has various health benefits such as antioxidants, immunomodulators, anti-inflammatory, anticancer, antiviral and antibacterial and has a positive effect on hyperlipidemia, malnutrition, obesity, metal poisoning and anemia (n’djamena, 2012). spirulina platensis antioxidants have activity against several types of free radicals such as hydroxyl and peroxyl radicals and preventing the occurrence of dna damage(soni et al., 2015). hydroxyl radicals play an important role in the lipid peroxidation process where the final product is mda(ayala et al., 2014). this study provides exposure to vehicle emission in experimental animals for 14 days. pm2.5 contained in vehicle emission caused the presents of free radicals which will cause oxidative stress. oxidative stress will trigger lipid peroxidation which in turn will increase serum mda levels (manzetti and andersen, 2016; gong et al., 2013). el-baz et al. (2013) was reported that spirulina platensis extract had a beneficial effect in controlling hyperglycemia and significantly lowering mda levels of type 2 dm rats compared to a control group. another study was conducted on mice given furan, a food contaminant and pollutant. commonly, spirulina platensis supplementation at a dose of 300mg / kgbw can significantly reduce mda levels compared to the control group (yudiati et al., 2011). in line with these studies, this study can prove that giving spirulina platensis extract can improve lipid peroxidation conditions that occur in rats with given exposure to vehicle emission. this can be seen from the finding of significant differences in the mean mda levels between the group given the 750mg / kgbw. spirulina platensis extract and the control group that was given vehicle emission smoke exposure. however, there were no significant differences between the groups given spirulina platensis extract 500mg / kgbw, this is © 2020 the authors. page 87 of 89 fitry et. al. indonesian journal of environmental management and sustainability, 4 (2020) 85-89 probably due to the insufficient dose given to prevent lipid peroxidation. in addition, oxidative stress was increased levels of ros because of the inflammation (xu et al., 2013; cho et al., 2018). inflammation is a non-specific immune response to clear pathological agents. the first response to inflammation is the recruitment of neutrophils that kill foreign bodies. once recruited, neutrophils release cytokines responsible for monocyte recruitment (xu et al., 2013). in vitro data suggest that the organic and transition metal constituents (e.g., fe, cu, ni, and zn) contained in pm are capable of producing ros directly or as a result of its ability to activate neutrophils or other leucocytes (delfino et al., 2011). according to steenhof et al. (2014), a positive association between pm and neutrophil count after 2 hours of exposure and monocytes after 18 hours of exposure in populations exposed to pm in underground areas. another hands by (al-homaidan et al., 2016) showed that pm2.5 can significantly increase the number of neutrophils, eosinophils and lymphocytes in bronchoalveolar lavage fluid (balf ) (yan et al., 2017). this study shows that giving spirulina platensis extract can affect inflammatory conditions that occur in experimental animals. this can be seen from the finding of significant differences in the mean absolute value of neutrophils and lymphocytes in the group given spirulina platensis extract at doses of 500 and 750 mg / kgbw with the control group given smoke exposure. significant differences were also found in the mean absolute values of eosinophils and monocytes between the group given spirulina platensis extract at a dose of 750mg / kgbw and the control group, but there was no significant difference between the group given spirulina platensis extract 500mg/kgbb and the control group. 4. conclusions based on results of this study, it was found that there was an effect of giving spirulina platensis extract on serum mda levels and wistar rats leukocyte counts exposed to vehicle emission. the administration of spirulina platensis extract at a dose of 750mg/kgbw had an effect on serum mda levels and the absolute value of eosinophils and monocytes, and doses of 500 and 750mg/kgbw on the absolute values of neutrophils and lymphocytes. references abd el-hakim, y. m., w. a. mohamed, and a. e. elmetwally (2018). spirulina platensis attenuates furan reprotoxicity by regulating oxidative stress, inflammation, and apoptosis in testis of rats. ecotoxicology and environmental safety, 161; 25–33 al-homaidan, a. a., a. f. al-abbad, a. a. al-hazzani, a. a. al-ghanayem, and j. a. alabdullatif (2016). lead removal by spirulina platensis biomass. international journal of phytoremediation, 18(2); 184–189 al-qahtani, w. h. and m. a. binobead (2019). antiinflammatory, antioxidant and antihepatotoxic effects of spirulina platensis against d-galactosamine induced hepatotoxicity in rats. saudi journal of biological sciences, 26(4); 647–652 ayala, a., m. f. muñoz, and s. argüelles (2014). lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-hydroxy-2-nonenal. oxidative medicine and cellular longevity, 2014 birben, e., u. m. sahiner, c. sackesen, s. erzurum, and o. kalayci (2012). oxidative stress and antioxidant defense. world allergy organization journal, 5(1); 9–19 cho, c.-c., w.-y. hsieh, c.-h. tsai, c.-y. chen, h.-f. chang, and c.-s. lin (2018). in vitro and in vivo experimental studies of pm2. 5 on disease progression. international journal of environmental research and public health, 15(7); 1380 delfino, r. j., n. staimer, and n. d. vaziri (2011). air pollution and circulating biomarkers of oxidative stress. air quality, atmosphere & health, 4(1); 37–52 el-baz, f., h. f. aly, a. el-sayed, and a. a. mohamed (2013). role of spirulina platensis in the control of glycemia in dm2 rats. int j sci eng res, 4; 1731–1740 gong, j., t. zhu, h. kipen, g. wang, m. hu, p. ohmanstrickland, s.-e. lu, l. zhang, y. wang, p. zhu, et al. (2013). malondialdehyde in exhaled breath condensate and urine as a biomarker of air pollution induced oxidative stress. journal of exposure science & environmental epidemiology, 23(3); 322–327 lee, h., w. myung, b.-h. jeong, h. choi, b. w. jhun, and h. kim (2018). short-and long-term exposure to ambient air pollution and circulating biomarkers of inflammation in non-smokers: a hospital-based cohort study in south korea. environment international, 119; 264–273 lu, x., z. ye, s. zheng, h. ren, j. zeng, x. wang, p. a. jose, k. chen, and c. zeng (2018). long-term exposure of fine particulate matter causes hypertension by impaired renal d1 receptor–mediated sodium excretion via upregulation of g-protein–coupled receptor kinase type 4 expression in sprague-dawley rats. journal of the american heart association, 7(1); e007185 manzetti, s. and o. andersen (2016). biochemical and physiological effects from exhaust emissions. a review of the relevant literature. pathophysiology, 23(4); 285–293 n’djamena, c. (2012). changes in the physico-chemical properties of spirulina platensis from three production sites in chad. journal of animal & plant sciences, 13(3); 1811–1822 soni, a., m. dubey, m. verma, r. dhankhar, v. kaushal, r. atri, and r. sabharwal (2015). revisiting the role of phycocyanin in current clinical practice. international journal of pharmaceutical sciences and research, 6(1); 4950–4600 steenhof, m., n. a. janssen, m. strak, g. hoek, i. gosens, i. s. mudway, f. j. kelly, r. m. harrison, r. h. pieters, © 2020 the authors. page 88 of 89 fitry et. al. indonesian journal of environmental management and sustainability, 4 (2020) 85-89 f. r. cassee, et al. (2014). air pollution exposure affects circulating white blood cell counts in healthy subjects: the role of particle composition, oxidative potential and gaseous pollutants–the raptes project. inhalation toxicology, 26(3); 141–165 who (2016). ambient air pollution: a global assessment of exposure and burden of disease xu, x., s. y. jiang, t.-y. wang, y. bai, m. zhong, a. wang, m. lippmann, l.-c. chen, s. rajagopalan, and q. sun (2013). inflammatory response to fine particulate air pollution exposure: neutrophil versus monocyte. plos one, 8(8); e71414 yan, x.-d., q.-m. wang, c. tie, h.-t. jin, y.-x. han, j.-l. zhang, x.-m. yu, q. hou, p.-p. zhang, a.-p. wang, et al. (2017). polydatin protects the respiratory system from pm 2.5 exposure. scientific reports, 7(1); 1–11 yudiati, e., s. sejati, s. sunarsih, and r. agustian (2011). aktivitas antioksidan dan toksisitas ekstrak metanol dan pigmen kasar spirulina sp. ilmu kelautan: indonesian journal of marine sciences, 16(4); 187–192 © 2020 the authors. page 89 of 89 introduction experimental section spirulina platensis extract vehicle emission and exposure setting system procedure of wistar mice exposure statistical analysis using anova results and discussion serum mda levels differential leukocyte counts conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper water quality assessment based on biological and chemical analysis as a parameter for development of fresh water fishery in lubuk karet river of banyuasin district carli junicef vratama1*, siti masreah bernas1, mohamad amin1, 1 environmental management program, graduate school of sriwijaya university, jl. padang selasa, no. 524, bukit besar, palembang, south sumatra, indonesia *corresponding author e-mail: emilia_lia89@yahoo.com abstract lubuk karet river is a river that surrounded by swamps with various kinds of plants and grasses. the lubuk karet river has the potential for the development of aquaculture which can be the business part of lubuk karet village community. this research was aimed to conduct an assessment effort in order to measure the capability of lubuk karet river for any aquaculture activities. the method used in this study is purposive sampling by conducting water quality assessment through biological and chemical parameters to support the development in that region. the results of this test can be a benchmark of fish species that can be cultivated in the lubuk karet river. the results of the chemical and biological parameters showed that the lowest do content at station 2 was 3.11 mg/l and the highest bod content at station 1 was 4.7 mg/l, the highest at station 1 was 606 mg/l, the highest tss content 50 mg/l, the highest nitrate content at station 1 was 6,54 mg/l, the highest phosphate content at station 2 was 0.098 mg/l, the highest cod content at station 2 was 5,61 mg/l, salinity was 0, the highest content at station 2 was 9,71 mg/l and the lowest ph value at station 5 was 2.96. from these results, it can be concluded that for further utilization for aquatic culture, some treatments must be conducted. keywords river, exploration, fishery, chemical parameter, biological parameter received: 12 march 2018, accepted: 4 may 2018 https://doi.org/10.26554/ijems.2018.3.2.64-68 1. introduction the lubuk karet river was surrounded by swamps and various plants such as kumpai grass (hymenachine amplexicaulis), gelam (melaleuca sp.), and nipah (nypa fruticans). the area of swamp that surrounds the lubuk karet river ranges from 2040 m2. swamps in the lubuk rubber river have the potential for the development of agricultural and �shery activities where the ownership of the land belongs to the government of lubuk karet village. hence, it can be utilized by residents around the river that is domiciled in lubuk karet village. most of the people around the lubuk karet river work as farmers and �shermen. the existence of the river can be utilized by the surrounding residents. utilization of aquatic resources optimally and continuously can be developed to support the �shery sector in lubuk karet river. fish cultivation in a cage can be used as one alternative source of income to improve the welfare of the community who generally work as farmers and �shermen. water quality is the main factor that can in�uence optimal and sustainable �sh management. the survival, development, growth and production of �sh that can support the activities of �sh cultivation in the cage (cholik et al., 1986). considering the importance of the role of water quality to �shery activities in the lubuk karet river, hence the effort for assessing the water quality must be conducted. in this work, the water quality of the lubuk karet river was assessed according to the chemical and biological parameters. the chemical parameter assessment was carried out by measuring the dissolved oxygen (do), biological oxygen demand (bod), chemical oxygen demand (cod), total dissolved solid (tds), total suspended solid (tss), salinity, ammonium content, and ph. the biological parameters analysis was carried out by measuring the diversity of �sh, plankton, and bentos. the goal of this research was to identify the characteristic of water quality of lubuk karet river. the results obtained from this research is hoped to be a reference and a benchmark for the exploration of the �sh species that can be cultivated in the lubuk karet river. 2. experimental section 2.1 research location this research was conducted in lubuk karet river located in lubuk karet village, betung subdistrict of banyuasin, south https://doi.org/10.26554/ijems.2018.3.2.64-68 vratama et. al. indonesian journal of environmental management and sustainability, 3 (2018) 64-68 figure 1. sampling location sumatra (figure 1). the whole research samples were collected on june to july 2017 at the rainy and dry season. 2.2 materials and instrumentation materials used in this work including various kinds of chemical for water quality test. the do analysis was conducted using do meter es-70, bod analysis was conducted in the environmental agency (blh) laboratory of banyuasin district. ph value of the water samples was measured with lutron ph 222 instrument. the biological parameters of plankton and benthos was collected using plankton net and the sampling location was determined using gps garmin map 62sc. 2.3 method the research method used in this work was a survey method that used a purposive sampling. the determination of station conducted by considering the properties of the river that represented the whole river that will be used as �sheries activities). for the data survey, the tabulation and regression and direct sampling at the stationary points and direct observation in the �eld, data collection and laboratory analysis based on insitu and exsitu method. the variables used in this work including water quality based on the chemical and biological analysis. the chemical analysis of the samples including do, co2, bod, tds, tss, nitrate, phosphate, cod, salinity, and ammonium content analysis. the biological analysis was conducted by analyzing the presence and the abundance of �sh, plankton, and benthos in the collected water samples. water sample collection was divided into �ve observation stations in which the distance of each station was ±6 km and each station was named as station 1, 2, 3, 4, and 5. 2.4 analysis of plankton data identi�cation of plankton diversity in the collected sample was conducted in the lab with the accuracy of the analysis was determined to the genus stage. the procedure of the plankton analysis was conducted as follow. the bottle containing plankton sample was shaken gently until homogenous. then the sample solution was taken using a pipette and dropped to the sedgwick rafter counting cell with maximum capacity 1 ml. the observation of the sample then carried out using a microscope with magni�cation 10 x 10 ml. 2.4.1 plankton abundancy analysis the plankton abundancy was described as the individual per liter. the plankton abundancy can be measured by the following equation (junaidi et al., 2013): n = ns×va vs×vc (1) where n is the plankton abundancy per liter of sample (ind./l), ns is the amount of plankton at the sedgwick rafter counting cell (individual), vs is the volume of water at the sedgwick rafter counting cell (ml), va is the volume of water concentrated in the sample bottle (ml), and vc is the volume of �ltered water (l). 2.4.2 species diversity index the index of species diversity was calculated according to the following equation. h1 =− ∑ pi lnpi (2) where pi is equal with ni/n. n is the number of total individual in the community. h1 is the diversity of species or shanon index and ni is the number of individual of each species. the value of h1 then grouped in the the following criteria. h1 < 1 means that the biota community is not stable. 1 ≤ h1 ≤ 3 means that the biota community in average of stability. h1 > 3 means that the biota stability is in good condition or highly stable. 2.4.3 domination index the domination index of simpson can be described by the following equation. c =− ∑ (pi) 2 (3) where pi equal to ni/n, c is the domination index, ni is the number of individual of each species. n is the number of total individual within the community. the value of c can de separated according to the following criteria. the value of c between 0 to 1, if the c value approaching zero, it means that there is no dominating species. however, if the c value is approaching 1, it means that there is a dominating species. 3. results and discussion 3.1 assessment of water quality in lubuk karet river the assessment of water quality in the lubuk karet river was carried out by two kinds of parameter i.e., chemical and biological parameters. all of these water quality assessments were © 2018 the authors. page 65 of 68 vratama et. al. indonesian journal of environmental management and sustainability, 3 (2018) 64-68 conducted in the two season, rainy season and dry season. this test is conducted to study the water quality of the lubuk karet river and the potential of �sheries that can be developed in the river. 3.1.1 chemical parameter analysis the content of do on the lubuk karet river shows that some types of �sh are able to develop well. there are several types of �sh that can survive with low do content. some �sh can live well on oxygen content of less than 4 ppm, especially �sh that have additional breathing apparatus. this extra breathing apparatus helps the �sh take oxygen directly from the air. cat�sh (clarias, sp), three spot gourami �sh (trichogaster, sp), snakehead �sh (chana striata) and gouramy (osprhronemus gourami) are �sh with additional breathing apparatus (e�endi, 2003). the results of bod parameter analysis in the study sites showed a range of values of 1.6 mg/l 4.7 mg/l. the results obtained in the study are still above the water quality standard speci�ed for freshwater �sh activities according to the standard quality of pergub lh. no. 16. year 2005. according to zonneveld (1991) states that the standard content of bod in a water for freshwater �sh is 6 mg/l, good for the continuity of �sh farming activities. the content of tds in the rubber lubuk river as a whole has an excellent value for �sh farming with a range of 51 mg/l 606 mg/l. the content of tds in the river lubuk karet is included in the value of quality standards. pergub lh.no.16.tahun 2005 states the requirement of tds content does not exceed 1000 mg/l. in accordance with khairuman and amri (2003) also states the range of tds for �sh cultivation activities that is 1000 mg/l where the value of good tds can support the activities of aquaculture. 3.1.2 tss (total suspended solid) the content of tss in lubuk karet river has a value between 5 mg/l 50 mg/l where the content of tss is still good. pergub.lh.no.16. year 2005 states maximum content for tss 20 mg/l. so the value of tss in the river lubuk rubber can be said good and feasible for aquaculture where the content of tss can support the phytoplankton life process. high concentrations of suspended solids greatly reduce the penetration of sunlight into the water so that the heat received by surface water is not e�ective enough for photosynthesis (tarigan, 2010). 3.1.3 nitrate content the content of nitrate in the highest dry season at station 5 is 0.199 and the lowest at station 3 is 0,094 mg/l. in the rainy season, the highest nitrate content at station 1 is 6.54 mg / l and the lowest at station 4 is 2.07 mg/l. from the existing content of both dry and rainy season can still be said to be good category according to quality standard for aquaculture (pergub.lh.no.16.2005) .the level of nitrate toxicity of �sh is very low, mortality caused by �sh when the concentration reaches 1000 mg/l, while the maximum value of concentration for �sh culture is 60 mg/l according to wyk f. and scarpa (1999). phosphate content in rainy season and dry season in lubuk karet river is the highest in station 2 with value 0,098 mg/l and in rainy season there is at station 3 with value 0,081 mg/l. in dry season the lowest phosphate content is found in station 3, that is 0,014 mg/l and in rainy season at station 1 is 0,015 mg/l. the results of calculations during the rainy and dry seasons indicate that the value of phosphate quality standard in the waters of river lubuk rubber is included in the quality standard (in accordance with the standard quality standards according to pergub.lh.no.16. year 2005). according nuryanto et al. (2015) suggests that the phosphate content of more than 0.051 mg/l then the waters can be said to be good. the highest cod value during the rainy and dry season is at station 2 with a cod content of 56.1 mg/l and at station 1 with a content of 44.7 mg/l. the lowest cod value in the rainy season is at station 3 of 29 mg/l and at station 3 of 4.48. the high value of cod at the research station is in�uenced by several factors: organic material that is not degraded or decomposed, one of which comes from the crude oil processing industry (cpo), in other words the source of organic material is derived particles that precipitate from the surrounding swamp empties into the river. according nuryanto et al. (2017) industry is the main source of organic waste and is the main cause of high concentrations of cod in a waters. meanwhile, according to yusuf and handoyo (2004) the cod value for aquaculture is < 80 mg/l and ideally < 25 mg/l. the value of quality standard for cod according to pergub lh.no.16 year 2005 is less than 50 mg/l, this indicates that the cod content in the lubuk rubber river is good for aquaculture. 3.1.4 salinity the salinity value on the measurements of each sample and season shows the salinity content value of 0 mg / l. the results of this calculation indicate that the lubuk rubber river is not a�ected by salinity of sea water. according to novotny and olem (1994) salinity in waters is a�ected by heat �ux, precipitation, river �ow (�ux) and current circulation patterns. salinity according to boyd (1982) based on the ability of �sh that adjust to certain salinity, can be classi�ed into �sh that have a small salinity tolerance (stenohaline) and �sh that have a wide salinity tolerance (euryhaline). according to pergub lh.no 16 year 2005 salinity value in lubuk karet river during the rainy season included in the quality standard that is 0 whereas in dry season the salinity value is 0.1 which is still tolerable �sh which categorized have very small salinity tolerance. 3.1.5 ammonium content ammonia content during the highest rainy season at station 1 is 2.73 mg / l and the lowest ammonia content at station 4 is 0.106 mg / l. ammonia content during the rainy season has a linear regression value above 0.5 or close to 1. this indicates that the ammonia content in the lubuk karet river has a rela© 2018 the authors. page 66 of 68 vratama et. al. indonesian journal of environmental management and sustainability, 3 (2018) 64-68 figure 2. amount of plankton in the rainy and drain season tionship between station 1 to station 5. during the dry season the highest value at station 2 is 9,71 mg / l and the lowest ammonia content at station 4 is 0,092 mg / l. ammonia content in lubuk karet river is not included in the quality standard for aquaculture. according to tarigan (2010) the factors a�ecting ammonia in waters are in�uenced by organic matter, dissolved oxygen and turbidity. this increased ammonia compound, will increase the growth and density of phytoplankton. the high density of phytoplankton leads to an explosion in population (blooming), followed by die-o� of phytoplankton. events of population explosions and mass mortality of phytoplankton will worsen the quality of river water. decreasing the quality of river water can also spur the emergence of various diseases in �sh. the highest ph value during the rainy season is 5.68 at station 1 and the lowest at station 5 is 4.74. the ph value during the highest dry season at station 1 is 6.48 and the lowest at station 5 is 2.96. the ph value in lubuk karet river does not meet the established quality standard for aquaculture. at the point of station 1 dry season entering for the standard of aquaculture cultivation. the ph value of the lubuk karet river is in�uenced by the concentration of gases in rivers such as co2, the concentrations of carbonate and bicarbonate salts and the decomposition of organic matter in the bottom of the waters. naturally, the ph of the waters is in�uenced by the concentration of carbon dioxide (co2) and acidic compounds. changes in ph become sensitive to most aquatic biota. aquatic organisms prefer ph to neutral ph (novotny and olem, 1994). 3.2 biological parameters assessment the number of plankton during the highest rainy season at station 2 is 5844 species and the lowest number of plankton at station 3 is 814 species, the number of plankton in the lubuk karet river is di�erent in the dry season. in the dry season the highest number of plankton at station 1 is 282 species and the lowest number of plankton at station 3 is 814 species. the number of plankton itself is in�uenced by various factors both physics and chemistry as shown in figure 2. the composition of plankton found in the dry season in the lubuk karet river consists of zooplankton and phytoplankton. zooplankton was found to consist of �ve classes: mastigophora, crustacea, ciliata, monogononta and digononta, while phytoplankton was found to consist of three classes: bacillariophyceae, cyanophyceae and chlorophyceae. plankton composition in the dry season more than in the rainy season. seen in the dry season found eight classes consisting of zooplankton and phytoplankton, but in the rainy season has more individual numbers of 13,557 individuals when compared to the dry season that only found as many as 687 individuals. fluctuations in the presence of plankton in the lubuk karet river show that the season is very in�uential. as barus (2004) points out, the seasons will a�ect environmental factors such as temperature, dissolved oxygen and current velocity, so that with seasonal changes it may also a�ect biota conditions in the area. the degree of diversity in the observations of each station can be seen in stations 1 and 3 where high phytoplankton diversity with values of 1.838 and 1.680 is inversely proportional to the low zooplankton values of 1.4075 and 1.0728. the diversity value at the high zooplankton station is 1.5614 and the value of the phytoplankton diversity of 0.713, the value can be interpreted the diversity of phytoplankton and zooplankton a�ect each other by each other. the value can be suspected that there are some high-diversity phytoplankton to zooplankton type which resulted in unstable plankton level existing in the observation station. at stations 2 and 5 the values of phytoplankton and zooplankton are more stable with each other ie 1.0734 and 1.5614. this is thought to be in�uenced by the presence of phytoplankton in these waters, in the food chain phytoplankton to be a source of food for zooplankton either directly or indirectly. zooplankton which is heterotrophic will eat phytoplankton directly, while indirectly zooplankton herbivor will be eaten by zooplankton carnivores and other animals of larger size, including �sh (nuryanto et al., 2015). the level of diversity in the observation of each station can be seen in station 2 where the high phytoplankton diversity with the value of 0.637 and zooplankton value 0. at stations 1, 4 and 5 the phytoplankton values are 0.803, 0.637 and 1.721. this is thought to be in�uenced by the presence of phytoplankton in these waters, in the food chain phytoplankton to be a source of food for zooplankton either directly or indirectly. zooplankton which is heterotrophic will eat phytoplankton directly, while indirectly zooplankton herbivor will be eaten by zooplankton carnivores and other animals of larger size, including �sh (nuryanto et al., 2015). 3.3 fish diversity observations show that there are twelve species of �sh found in the lubuk karet river of the whole species, meaning that the lubuk karet river has a high diversity of �sh species. the results show the number of �sh species ≥16. that number proves that �sh species found in the lubuk rubber river are high. this is directly proportional to the statement of nuryanto et al. (2015) that high species diversity can be ensured that support of good water quality. © 2018 the authors. page 67 of 68 vratama et. al. indonesian journal of environmental management and sustainability, 3 (2018) 64-68 figure 3. the comparation of diversity index of phytoplankton and zooplankton at the rainy season figure 4. the ralationship of diversity index between phytoplanton and zooplanton from the observations made in the river lubuk rubber the data obtained is inversely proportional to the statement of nuryanto et al. (2017), the low diversity of �sh species present in the lubuk karet river is in�uenced by several factors such as the declining quality of water by palm oil industry waste, pesticides and herbicides as well as fertilization in oil palm plantations during rainfall will a�ect water quality due to emptying into lubuk rubber river and catching �sh using environmentally unfriendly tools (potassium poison) based on interviews with residents around the lubuk karet river it can be concluded that river rubber holes are low in number of species. 4. conclusions from the results of observation and sampling �eld found only 12 species of �sh. this is categorized as a river that has a low variety of �sh species. plankton from the observed samples taken were found from class 3 phytoplankton and 5 class zooplankton. from result of measurement of water quality of chemical parameter of lubuk rubet river both in rainy season and dry season show not included in standard class iii standard in accordance with pergub lh 2005 for �shery cultivation. the results of the analysis indicate that the lubuk karet river needs water quality processing before conducting aquaculture. this treatment aims to produce optimal �sh farming. types of �sh with tolerant values of low water quality conditions can be cultivated in the lubuk karet river. types of �sh such as cat�sh are the species that can be cultivated in the lubuk karet river. references cholik, f., a. hardjamulia, and r. arifudin (1986). budidaya perikanan. blpp supm negeri, bogor e�endi, h. (2003). telaah kualitas air bagi pengelolaan sumber daya dan lingkungan perairan. kanisius. yogjakarta. novotny, v. and olem (1994). water quality: prevention, identi�cation, and management of di�use pollution. new york: van nostrand reinhold nuryanto, a., d. bhagawati, m. abulias, and indarmawan (2015). fish diversity at cileumeuh river in district of majenang. cilacap regency. central java. jurnal iktiologi indonesia, 12(12) nuryanto, a., d. bhagawati, and m. n. abulias (2017). fauna ikan di sungai cikawung kabupaten cilacap jawa tengah [ichthyofauna in the cikawung river, cilacap regency, central java]. jurnal iktiologi indonesia, 15(1); 25–37 tarigan, m. s. (2010). kandungan total zat padat tersuspensi (total suspended solid) di perairan raha, sulawesi tenggara. makara journal of science wyk f., v. and j. scarpa (1999). waterqrslity rquirements and managemenl chapter 8. farming mar zonneveld, c. (1991). estimating death rates from transect. ecological entomologi, 16(1); 115–121 © 2018 the authors. page 68 of 68 introduction experimental section research location materials and instrumentation method analysis of plankton data plankton abundancy analysis species diversity index domination index results and discussion assessment of water quality in lubuk karet river chemical parameter analysis tss (total suspended solid) nitrate content salinity ammonium content biological parameters assessment fish diversity conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper spirulina platensis extract reduces serum tnf-α, neutrophils, and increases macrophage count in skin incisional mice model riski dwi utami1, tri nur kristina2*, renni yuniati3 1department of biomedicine, school of medicine, medical faculty of diponegoro university, semarang, central java, indonesia 2department of microbiology, medical faculty of diponegoro university, semarang, central java, indonesia 3department of dermatology-venereology, medical faculty of diponegoro university, semarang, central java, indonesia *corresponding author e-mail: renniyuniati@yahoo.com abstract spirulina sp. is an alga that has antioxidant and anti-inflammatory potential. phycocyanin contained in spirulina platensis can reduce tumor necrosis factor-α levels, neutrophils, and m2 macrophages in inflammation. this research aims to investigate the anti-inflammatory activity of s. platensis in a mice wound model. thirty-two male wistar rats were incised and divided into 4 groups. the first therapeutic group (x1) received s. platensis extract at a dose of 500 mg/kgbw/day, and the second therapeutic group received s. platensis extract at a dose of 750 mg/kgbw/day. the negative control group (c1) received a saline solution and the positive control group (c2) received diclofenac sodium 20mg/kgbw/day. serum tnf-α levels examined by the enzyme-linked immunosorbent assay method. neutrophils and m2 macrophages were calculated by tissue biopsy and hematoxylin-eosin (he) staining. data analysis was performed with anova test and lsd post-hoc test. the average levels of serum tnf-α on the 14-day were 394.50; 180.33; 2,980.33; and 607.42 pg/ml for x1, x2, c1 and c2, respectively. the average neutrophils number on the 14-day were 8.00; 6.83; 14.67; and 11.17 for x1, x2, c1 and c2, respectively. the average macrophage number in the 14-day was 15.50; 19.17; 6.33; and 11.17 for x1, x2, c1 and c2, respectively. we found significant differences between tnf-α levels, the number of neutrophils, and the number of m2 macrophages. the administration of s. platensis extract at a dose of 750 mg/ kgbw/day reduces serum tnf-α levels, neutrophil count, and increases m2 macrophages in skin incisional mice model. keywords spirulina platensis, anti-inflammatory, tnf-α, neutrophils, macrophages. received: 3 june 2020, accepted: 12 june 2020 https://doi.org/10.26554/ijems.2020.4.2.34-38 1. introduction skin is the largest organ of the body that works as a firstline barrier to toxins, trauma, and pathogens. any breach on the skin surface disrupts the skin’s protective barrier function and may result in the formation of scars when the wound heals. there are several steps of wound healing, such as hemostasis, inflammation, proliferation, and maturation.(rohl et al., 2015; martin and nunan, 2015) the inflammatory phase in the wound healing process cleans damaged cells, extracellular matrix and helps to inhibit the growth of pathogenic organisms. this phase lasts about 5-7 days. excessive inflammation phase can cause chronic inflammation, inhibits re-epithelialization and increases the occurrence of fibrosis.(rohl et al., 2015). the inflammatory phase of the wound in the skin denotes the entry of mast cells, monocytes, neutrophils, and t cells that originate from capillaries into the tissues. neutrophils and macrophages enter the wound area in the initial phase of inflammation at different times. neutrophils arrive at the wound area approximately in the first 6-12 hours, and they reach a peak one day after injury. (rohl et al., 2015; gonzalez et al., 2016). neutrophils migrate through the process of diapedesis in capillary endothelial cells and activated by proinflammatory cytokines such as interleukin (il)-1β, tumor necrosis factor (tnf)-α and interferon (ifn-γ) .(karnen, 2012). macrophages enter the wound area in large numbers up to 48 hours after injury and the number is stable on days 4-5; furthermore, they continue to decline until the 14-day. macrophages will differentiate into various kinds of cells with different functions. at the initial phase of inflammation, macrophages will differentiate into proinflammatory m1 macrophages. m1 macrophages are classified as phagocytosing bacteria, which can be produced tnf-α, il-6, and il-23. https://doi.org/10.26554/ijems.2020.4.2.34-38 utami et. al. indonesian journal of environmental management and sustainability, 4 (2020) 34-38 m1 macrophages can be differentiated into m2 macrophages after the phagocytic process of apoptosis in response to the cytokines il10 and il4. m2 macrophages possess wound repairing abilities and they release growth factors such as tgf-β, vascular endothelial growth factor (vegf), and platelet-derived growth factor (pdgf)-β which recruit endothelial (pro-angiogenic) cells and fibroblasts, promote myofibroblast differentiation and secrete extracellular matrix components.(rohl et al., 2015). pharmacological therapies are useful to reduce symptoms and to speed up the healing process of the wounds. one of the therapeutic modalities that can be used is phyto therapeutics (levine, 2017)., which has various potentials, one of them is phytotherapeutic potential.(bps, 2014; nur, 2014; triyono, 2013). spirulina sp. is a type of cyanobacteria that grows in water, freshwater, brackish water or saltwater. growth and nutrient content of spirulina sp. are influenced by factors such as light intensity, temperature, growth media, ph and salinity. phycocyanin plays a big role in anti-inflammatory activities.(nur, 2014; wu et al., 2016). phycocyanin and β-carotene of spirulina sp. play an important role in the anti-inflammatory effects.(wu et al., 2016). the blue pigment phycocyanin in s. platensis works as an anti-inflammatory agent, by acting as a selective inhibitor of the cyclooxygenase-2 (cox-2) enzyme, inhibiting the production of nitric oxide (no) and prostaglandin e2.(wollina et al., 2018). besides, phycocyanin is also able to inhibit the expression of tnf-α, and il-6.9 βcarotene also has antioxidant and anti-inflammatory effects by inhibiting the production of inducible nitric oxide synthase (inos), cox-2, tnf-α, and il-1β.(sorg et al., 2017). the previous study had concluded that s. platensis has an anti-inflammatory effect on acute and chronic inflammation.(quader et al., 2013). besides that, s. platensis extract significantly influences wound healing through granulation tissue formation and neovascular enhancement in the wound area. wound healing, especially chronic wounds, is not easy to heal due to various disturbances and chronic inflammation in the wound bed. therefore, we aimed to evaluate the potency of s. platensis extract as a novel wound-healing enhancement agent. we hypothesized that s. platensis could reduce inflammation that happened in the wound bed, which can be measured by tnf-α, macrophage count, and neutrophil count as inflammation indicators. 2. experimental section 2.1 materials the extraction of s. platensis requires 95% ethanol. the materials needed for the maintenance of experimental animals and incision procedures are ad-shaped pellet type ii, reverse osmosis drinking water, 70% alcohol and 10% ketamine. for the examination of serum tnf-α levels, we used the rat tnf-α elisa kit (catalog no. e-el-r0019: elab science biotechnology, texas, usa). for examination of neutrophil and macrophage counts, we used formalin as a natural buffer, alcohol with multilevel concentration (10%, 70%, 80%, 90%, 95% and 100%), paraffin, xylol, and mayer’s hematoxylin stain. 2.2 collection and extraction of s. platensis the s. platensis used in this study were obtained as s.platensis powder with us fda registration number of 15594742028 and ceres number of 50oga1200043 (9241). the powdered s.platensis microalgae were macerated in 95% ethanol solution with 1:10 concentration (one part of s.platensis powder macerated in 10 parts of 95% ethanol solution). the maceration process done for five days in a glass container. the glass container was stirred every day to make sure the uniformity of the maceration process. after five days, the solution was filtered through whatman and was evaporated using a rotary evaporator machine at the ethanol boiling point temperature until a thick extract was obtained. this extract of s.platensis was used as the material in the subsequent tests, further explained below. 2.3 experiment subjects thirty-two male pure-breed laboratory-grade wistar rats, 2-3 months obtained from a local laboratory rat breeder with a lineage certificate of with a bodyweight of 100-200 grams, were acclimatized for 7 days. the animal was fed with water and rat pellets ad libitum at the cage. the animals were randomly divided into 4 groups and were incised to make a wound on the skin of their backs. the first therapeutic group (x1) received s. platensis extract at a dose of 500 mg/ kgbw/ day (x1) orally, the second therapeutic group (x2) received s. platensis extract at a dose of 750 mg/ kgbw/ day orally, the negative control group (c1) received saline solution 0.9 % 0.5 ml and the positive control group (c2) received diclofenac sodium 20mg/ kgbw/ day orally using oral dosing (gavage) method. this study has been approved by health research ethics committee, faculty of medicine, sultan agung islamic university with ethical exemption certificate number 241/v/2019/komisi bioetik. 2.4 procedure of incision the mice were anesthetized using an intramuscular injection of 60 mg/kgbw ketamine. the hair of the rats was shaved about 1.5 cm to the right of the centerline on the back of the head and cleaned with 70% alcohol. the skin was incised using a 4 cm long scalpel parallel to the paravertebral lines until reaching the muscle layer. the wound was sutured with a simple interrupted suture technique at 0.5 cm intervals, and the suture was removed on the 7th day. 2.5 collection of blood and tissue samples one milliliter of the blood sample was obtained from the retroorbital blood vessels of the experimental rats on 7 and 14-days. we harvested the skin tissue nearest to the wound incision site, put it into a paraffin block, sliced and was processed for further histopathological analysis. © 2020 the authors. page 35 of 38 utami et. al. indonesian journal of environmental management and sustainability, 4 (2020) 34-38 table 1. serum tnf-α levels of experimental groups post-injury day groups mean ± sd (pg/ml) min-max (pg/ml) p values 7th day x1 377.83 ± 145.98 109.50-522.00 p < 0.001 x2 232.42 ± 40.54 164.50-277.00 c1 4634.08 ± 1956.02 2094.50-6707.00 c2 658.67 ± 35.38 612.00-719.50 14th day x1 394.50 ± 24.70 364.50-429.50 p < 0.001 x2 180.33 ± 39.10 134.50-229.50 c1 2980.33 ± 892.50 1707.00-4207.00 c2 607.42 ± 80.89 502.00-744.50 2.6 measurement of serum tnf-α levels measurement of serum tnf-α levels from blood samples was done using the elabscience rat tnf-α elisa kit, (catalog number e-el-r0019, elabscience biotechnology, houston, tx, usa). blood was left to clot for 2 hours at room temperature and centrifugated for 15 minutes. the supernatant was collected and was stored in a clean container. one hundred microliters of sample was put into the wells and was incubated for 90 minutes at 37 c. one hundred microliters of biotinylated detection antibody were added to the solution, and the plate was aspirated and washed three times. afterward, 100 µl of hrp conjugate working solution and 90 µl of substrate reagent was added and incubated according to the factory provided procedure. finally, 50 µl of stop solution was added and the plate was read using microplate reader at 450nm. 2.7 histopathology tissue samples were obtained through tissue biopsy on the 14th day. subsequently, the histological preparations and hematoxylin-eosin (h&e) staining were made. histological slides were analyzed by a pathologist by using a 40x magnification binocular light microscope (olympus cx23, shinjuku, japan). 2.8 statistical analysis the statistical analysis was done using spss for windows version 21. we used one-way anova and post hoc lsd test for further analysis. the statistical significance used in this study was set at p < 0.05. 3. results and discussion all of the mice used in this research were kept alive until the end of the measurement period. no mice were dropped out of the study. all of the mice were terminated after samples were taken following ethical termination rules. the mean baseline value of serum tnf-α levels on the pre-wounded mice was 34.89 ± 22.47 pg/ml. one-way anova analysis showed significant differences (p < 0,001) in serum tnf-α levels between study groups on both 7 and 14-days. on the 7th day, lsd post hoc tests showed significant differences were found between the x1 group and c1 group and between x2 group and the c1 and c2 groups. there were also significant differences between c1 and c2 groups. we also found significant differences on the 14th day between x1 group and x2, c1, and c2 group, between x2 group and both control groups, and between c1 and c2. (table 1) table 2. the changes of the number of neutrophils per field of view in experimental groups groups mean ± sd min-max p values x1 8.00 ± 2.366 4-11 p < 0.001 x2 6.83 ± 1.722 4-9 c1 14.67 ± 1.862 12-17 c2 11.17 ± 2.483 8-15 the results from table 2 showed that there was a significant difference between the negative control group and the first therapeutic group, which received s. platensis extract group with a dose of 500 mg/kg of body weight/day. moreover, significant differences were also found between the positive control group and both of the therapeutic groups. table 3 also shown the results of the changes in the number of macrophages in experimental groups. table 3. the changes in the number of macrophages in experimental groups groups mean ± sd min-max p values x1 15.50 ± 2.429 12-19 p < 0.001 x2 19.17 ± 2.317 16-22 c1 6.33 ± 1.862 4-9 c2 11.17 ± 1.329 9-13 analysis test showed that there was a significant increase in the number of m2 macrophages in the both of the therapeutic groups which received s. platensis extract compared to the negative and positive control groups. a significant difference was also found between the two ther© 2020 the authors. page 36 of 38 utami et. al. indonesian journal of environmental management and sustainability, 4 (2020) 34-38 apeutic groups, where the second therapeutic group had a significantly higher m2 macrophage compared to the first therapeutic groups. analysis test showed that there was a significant increase in the number of m2 macrophages in the both of the therapeutic groups which received s. platensis extract compared to the negative and positive control groups. a significant difference was also found between the two therapeutic groups, where the second therapeutic group had a significantly higher m2 macrophage compared to the first therapeutic groups. in this study, we found a significant difference in tnf-α levels between the experimental groups. normal levels of tnf-alpha in non-wounded rats were around 32 pg/ml, and on wounded rats was around 124.6 pg/ml.(rohl et al., 2015; martin and nunan, 2015) these results are in accordance with the previous study found that the administration of s. platensis extract orally at a dose of 500mg/ kgbw/ day was able to suppress acute inflammation induced by carrageenan and the administration duration of 7 days has the potential to inhibit chronic inflammation which was induced by granuloma. another study also shows that the administration of s. platensis could reduce tnf-α levels under the inflammatory process condition (wu et al., 2016). another study shows that the administration s. platensis extract at a dose of 20 mg/kg of body weight and 30 mg/kg of body weight in diabetic-induced mice decreases serum tnf-α levels (liu et al., 2016). cytokines play an important role in the inflammatory process through the production of proinflammatory cytokines such as tnf-α, il-1β, and il-6, which initiates the immune system in the inflammatory process.(liu et al., 2016). tnf-α is mainly produced by macrophages, endothelial cells, and mast cells. tnf-α increases adhesion molecules in inflammatory cells (neutrophils, monocytes) and endothelial cells.(owen et al., 2013; abbas et al., 2016). tumor necrosis factor-α is needed in the wound healing, especially in the inflammatory phase, because the inflammatory process is a physiological process in wound healing. however, if the inflammation in the wound healing process occurs too long, the wound may become a chronic wound. on the 7th day, tnf-α was still needed in the inflammatory phase of the wound healing process. however, the increase of tnf-α levels which continued for a prolonged period than normal indicated an extension of the inflammatory phase. anti-inflammatory agents produced by s. platensis are phycocyanin and β-carotene.(wu et al., 2016) as an antiinflammatory agent, phycocyanin contained in s. platensis works a selective inhibitor of the cyclooxygenase-2 (cox-2) enzyme which is regulated during the inflammatory process and has the ability to induce apoptosis in macrophages. other studies also concluded that phycocyanin was able to inhibit the expression of inos, cox-2, tnf-α, and il-6 while β-carotene was able to inhibit the production of inos, cox-2, tnf-α, and il-1β. (wu et al., 2016; sorg et al., 2017). in this study, we found that the mean tnf-α level of the control group was negative on the 7th day compared to the treatment group, which was given s. platensis extract. this result shows that there was a possibility that the administration of s. platensis extract may disrupt the wound healing process. this might happen because the average tnf-α levels in the treatment group were much lower than the negative control group. therefore, the timing of s. platensis administration is important to prevent the disruption of the wound healing process. the measurement of the number of neutrophils in wound tissue was done to analyze how the development of the inflammatory phase in the wound healing process. the presence of neutrophils at the wound inflammation area usually peaks within one day after the initiation of tissue injury, because the neutrophils are needed in the wound healing process to phagocytose bacteria and to secrete proteinase which works as an antimicrobial agent.(rohl et al., 2015; gonzalez et al., 2016) in acute wounds, the inflammatory phase lasts for less than 7 days. if the number of neutrophils continues to increase or persist until the 14th day, the inflammatory phase might be prolonged and the wound might become chronic wounds.(rohl et al., 2015). the results of this study indicate that the administration of s. platensis extract has the potential to reduce the number of neutrophil inflammatory cells compared to the control group. these results are consistent with a previous study that found that the phycocyanin content possessed by s. platensis has an anti-inflammatory effect. one of the anti-inflammatory effects possessed by s. platensis extract is the inhibition of neutrophil migration to the area of inflammation. (liu et al., 2016). macrophages are involved in the inflammatory and proliferation phase of the wound-healing phase. macrophages entered the area of injury in large numbers up to 48 hours after injury and the number was stable on days 4-5. furthermore, they continued to decline until the 14th day. macrophage assessment in this study was conducted on the 14th day of wound healing, which was purposely done to let the macrophages differentiate into m2-type anti-inflammatory macrophages. the therapeutic groups which received s. platensis extract show a significant effect on increasing m2 macrophages compared to the control group. therefore, the administration of s. platensis extract helped the wound healing process by increasing the amount of m2 macrophages. the results of this study differ from a previous study, which might be attributed to the difference in data collection time. their previous research showed that the number of macrophages in the group which received s. platensis extract increased significantly on the 3rd day. however, it started to decrease in the 7, 12 and 13-days. therefore, an immunohistochemical examination should be carried out to ascertain the type of macrophage. besides, it is necessary to examine proinflammatory, other anti-inflammatory cytokines, and © 2020 the authors. page 37 of 38 utami et. al. indonesian journal of environmental management and sustainability, 4 (2020) 34-38 the growth factors to see the effectiveness of s. platensis in the healing of proliferative and remodeling phases. there are several limitations in this study that can be studied in the future, such as the measurement of wound healing markers, preferably should have been done together with the microscopic (histopathological) analysis to accurately measure the wound healing process and its correlation with the wound healing markers. 4. conclusions s. platensis extract was found to have the capability to reduce serum tnf-α levels, reduce the number of neutrophils, and significantly increase the amount of anti-inflammatory m2 macrophages compared with the control groups. the administration of s. platensis extracts at a dose of 750 mg/kg body weight/day on the second experimental group has better potential to reduce serum tnf-α levels and increases the number of m2 macrophages when compared to the first experimental group which was given with s. platensis extract at a dose of 500 mg/kg body weight/ day. 5. acknowledgment this study was supported by department of biomedical, medical faculty of diponegoro university and supported by abdurrab university. references abbas, a., lichtman, and p. andrew (2016). basic immunology. 6th ed. elsevier bps (2014). badan pusat statistik. statistik sumber daya laut dan pesisir. technical report gonzalez, a. d. o., t. costa, z. d. a. andrade, and a. medrado (2016). wound healing a literature review. an bras dermatol, 91(5); 614–20 karnen, b. (2012). imunologi dasar. jakarta: badan penerbit fakultas kedokteran universitas indonesia; 132 levine, j. (2017). the effect of oral medication on wound healing. adv skin wound care, 30(3); 137–42 liu, q., y. huang, r. zhang, t. cai, and y. cai (2016). review article medical application of spirulina platensis derived c-phycocyanin. evidence-based complementary and alternative medicine; 1–14 martin, p. and r. nunan (2015). cellular and molecular mechanisms of repair in acute and chronic wound healing. br j dermatol, 173(2); 370–378 nur, m. (2014). potensi mikroalga sebagai sumber pangan fungsional di indonesia. eksergi, 9(2); 1–6 owen, j., j. punt, j. stanford, sharon, and k. patricia (2013). immunology kuby. 7th ed. new york: w.h freeman quader, s., s. islam, a. saifullah, and f. majumder (2013). the parma innovation-journal in-vivo studies of the inflammatory effects of spirulina platensis. pharma innov, 2013(4); 70–80 rohl, j., a. zaharia, m. rudolph, m. rz, r. murray, and j. röhl (2015). the role of inflammation in cutaneous repair. inst heal biomed innov, 23; 8–15 sorg, h., d. tilkorn, s. hager, j. hauser, and u. mirastschijski (2017). skin wound healing: an update on the current knowledge and concepts. eur surg res, 58(1); 81–94 triyono, k. (2013). keanekaragaman hayati dalam menunjang ketahanan pangan. innofarm j inov pertan, 11(1); 12–22 wollina, u., c. voicu, s. gianfaldoni, t. lotti, k. frança, and g. tchernev (2018). arthrospira platensis – potential in dermatology and beyond antioxidant activity. maced j of med sci, 6(1); 176–80 wu, q., l. liu, a. miron, b. kĺımová, d. wan, and k. kuča (2016). the antioxidant, immunomodulatory, and antiinflammatory activities of spirulina: an overview. arch toxicol, 90(8); 1817–40 © 2020 the authors. page 38 of 38 introduction experimental section materials collection and extraction of s. platensis experiment subjects procedure of incision collection of blood and tissue samples measurement of serum tnflevels histopathology statistical analysis results and discussion conclusions acknowledgment title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper effects of different incubation methods on ethanol production from selected food wastes products janet appiah osei1*, shyam manohar1, kitur esther1 1department of environmental sciences, kenyatta university, kenya *corresponding author e-mail: janetoseiappiah@gmail.com abstract the study describes the potential of producing bioethanol from corn (zea mays) cobs, collard greens (brassica oleracea) waste and banana (musa acuminate) peels using different methods of incubation. wastes were pre-treated by grinding into smaller particles and enzymatic hydrolysis was carried out using commercial cellulase from aspergillus niger. anaerobic fermentation was done using cultured saccharomyces cerevisiae yeast suspension. different incubation conditions (incubator, dark room and under soil) at different temperatures 30oc, 21oc and 19oc respectively were optimised for bioethanol production at different incubation times of 48, 96 and 144 hours. maximum bioethanol percentages of corn cobs, banana peels and collard greens were (0.48%), (0.39%) and (0.15%) respectively. the optimum conditions for maximum ethanol concentration in corn cobs was the incubator conditions at temperature 30oc and 144 hours; banana peels was under soil conditions at 19oc and 48 hours whilst collard greens was dark room conditions at 21oc and 48 hours incubation times. results obtained show the potential of producing bioethanol from corn cobs, collard greens and banana peels under different incubation conditions. use of incubators for fermentation especially in collard greens wastes and banana peels can successfully be replaced with dark room and soil which are more economically feasible. keywords bioethanol, hydrolysis, fermentation, corn cobs, collard greens wastes, banana peels received: 5 august 2020, accepted: 24 september 2020 https://doi.org/10.26554/ijems.2020.4.3.64-69 1. introduction bioethanol is known globally as a transportation fuel with economic and environmental merits. it is mainly used in inks and coatings as carrier solvents; in cosmetic preparations like hair setting sprays; in pharmaceutical and personal care products like mouthwashes and also in detergent preparations (gashaw and getachew, 2014). bioethanol was first utilized as a motor fuel in internal combustion engine that was invented by nikolas otto in 1897 but its establishment as an alternate fuel was in the 1970s during the oil crises. it is predominantly generated currently from corn and sugarcane derived feed stocks. these feed stocks are used to produce first generation bioethanol (lohri et al., 2017). drawback associated with use of energy crops for bioethanol production is their inadequacy in meeting higher fuel demands which may eventually lead to deforestation in order to obtain enough farmland. this negative impact has led to the evolvement of second-generation bioethanol which involves the use of agricultural residues, wood, paper and municipal solid wastes (saini et al., 2015). these materials consist of lignocellulose which is considered as a good raw material for the production of bioethanol. globally, lignocellulose is recognized as preferred biomass for fuels and chemicals production. it is the most abundant and widespread carbon source in nature and is known to be the only source capable of providing enough feedstock to meet the world’s energy and chemical needs in a renewable manner. lignocellulose materials can produce bioethanol up to 442 billion litres per year (woldesenbet et al., 2016). increased global per-person food supply has led to the generation of high quantities of waste in recent years (nair et al., 2017). leachate and uncontrolled anaerobic decomposition of food waste in landfills result in ground water contamination and greenhouse gases emissions (ali et al., 2016). high water quantity in food waste and possibility of dioxin formation make incineration also impractical. food wastes contain soluble sugar, starch, lipids, proteins, cellulose and other compounds making them good substrates for bioethanol production (moukamnerd et al., 2013). ethanol production from food waste will reduce the amount of waste in landfills and thus minimise environmental problems rehttps://doi.org/10.26554/ijems.2020.4.3.64-69 osei et. al. indonesian journal of environmental management and sustainability, 4 (2020) 64-69 lated to landfills (byadgi and kalburgi, 2016). bioethanol production from lignocellulose materials involves three main stages which are pre-treatment; hydrolysis and fermentation (sarkar et al., 2012). pre-treatment is used to separate bonds and release cellulose and hemicellulose to make them susceptible for the activities of chemical and biological agents (triana, 2016). hydrolysis converts feed stocks into fermentable sugars which are subsequently converted into bioethanol using micro-organisms (bacterium, yeast or fungi) under anaerobic conditions during fermentation (azhar et al., 2017) ; (woldesenbet et al., 2016); (li, 2008) . the overall chemical formula for fermentation is: c6h12o6 → 2c2h5oh + 2co2 the main objective of the study is to determine the amount of bioethanol produced from corn cobs, collard greens wastes and banana peels under different fermentation conditions. 2. experimental section 2.1 materials substrates used in this research were collard greens, banana peels and corn cobs obtained from nairobi market, kenya. microorganisms used were baker’s yeast (saccharomyces cerevisiae) purchased from nairobi market and cellulase from aspergillus niger purchased from (sigma aldrich, kobian scientific limited, nairobi, kenya). all chemicals used were analytical grade procured from biochemistry department in kenyatta university. 2.2 methods 2.2.1 waste preparation and pre-treatment collard greens (brassica oleracea), banana (musa acuminate) peels and corn (zea mays) cobs were oven dried at 110oc for two days after which they were physically pretreated by grinding using a grinder. 100 g of each pre-treated wastes were dissolved in 500 ml distilled water. ph was adjusted to 4.5 and sterilization was done using an autoclave at 120oc for 15 minutes. 2.2.2 enzymatic saccharification enzyme solution containing 2 g of commercial cellulase from aspergillus niger and 20 ml of 0.05 m citrate buffer solution at ph 4.8 was added to each sterilized substrate and incubated at 30oc on an incubating shaker with agitation rate of 200 rpm for 24 hours. the samples were centrifuged after incubation at 10,000 rpm for 10 minutes to obtain the hydrolysates. the concentration of glucose present in each food hydrolysate was determined by high performance liquid chromatography using the method described by (kim et al., 2011). 2.2.3 preparation of yeast inoculum and fermentation procedure saccharomyces cerevisiae inoculum was prepared in 250 ml cottonplugged conical flask which contained 100 ml ypd broth solution consisting of 20 g/l of dextrose, 4 g/l of yeast extract and 3 g/l of peptone at ph 7.0. solution was sterilized and 0.6 g baker’s yeast was added and incubated at 30oc for 48 hours on an incubating shaker with agitation rate of 150 rpm. fermentation was carried out in 50 ml cottonplugged conical flasks containing 20 ml of hydrolysates with ph 4.5. sterilization was done and hydrolysates were inoculated with 2 ml cultured yeast suspension and shaken at agitation rate of 200 rpm for 30 minutes. the methods of incubation used for the fermentation process were an incubator, dark room and under soil at different temperatures of 30oc, 21oc and 19oc respectively and at durations of 48, 96 and 144 hours. dark room and under soil temperatures were determined by the use of a thermometer. 2.2.4 analytical procedure aqueous phase samples were collected from each flask after 48, 96 and 144 hours of fermentation and centrifuged at 5000 rpm for 10 minutes to remove yeast cells and other solids present in the samples. supernatant fluid was filtered with a filter paper and the filtrate was used to determine the concentration of bioethanol. 2.2.5 bioethanol analysis biochemical method involving the use of potassium dichromate and sulphuric acid together with uv-vis spectrophotometer set at 620 nm was used in the analysis of bioethanol. standards were prepared using different volumes of 2% absolute ethanol together with 4 ml distilled water, 1 ml of 10% potassium dichromate solution and 2 ml concentrated sulphuric acid. a curve was drawn using the prepared standard solutions and their corresponding absorbance values. ethanol solutions from filtrates were also prepared using the same procedures for the standards and their absorbance values were also determined. the concentrations of bioethanol (%v/v) from collard greens wastes, banana peels and corn cobs were extrapolated from the standard ethanol curve. ethanol productivity was obtained from ethanol concentration divided by fermentation time and expressed as percentage ethanol per time in hours (%/ hr). 2.2.6 statistical analysis one way anova was used to analyse data and significant differences among means were separated at 5% level of probability (p<0.05) using genstat statistical package (discovery version 4) 3. results and discussion 3.1 bioethanol production at different incubation conditions and times the highest ethanol productivity and concentration was achieved in corn cobs followed by banana peels with collard greens wastes recording the lowest. the high glucose content in corn cobs and banana peels as seen from figure 1 is © 2020 the authors. page 65 of 69 osei et. al. indonesian journal of environmental management and sustainability, 4 (2020) 64-69 figure 1. percentage glucose content in corn cobs, banana peels and collard greens table 1. optical density of ethanol standard solutions serial number standard ethanol (ml) o.d at 620 nm 1 0.00 (blank) 0 2 0.2 0.188 3 0.4 0.278 4 0.6 0.365 5 0.8 0.466 6 1 0.547 figure 2. ethanol standard curve as a result of their high ethanol content. in anaerobic fermentation, glucose is converted to pyruvic acid through the embden-meyerhof-parnas (emp) pathway and pyruvic acid into acetaldehyde by the enzyme pyruvate decarboxylase and finally into ethanol with the assistance of the enzyme dehydrogenase (syawala et al., 2013). hence the higher the glucose content, the higher the quantity of ethanol produced. also leafy vegetables in contrast with the other substrates contain high amounts of antioxidants like phenolic components which inhibit yeast activity in producing bioethanol. (utama et al., 2019) reported low amount of ethanol in napa cabbage as compared to bananas and papayas wastes. the study by (cutzu and bardi, 2017) reported maximum amount of ethanol from corn threshing residue as compared to apple and kiwi fruits. (singh and singh, 2015) also reported high ethanol content from corn cob as compared to banana peels. table 2. maximum bioethanol concentration and productivity of collard greens, banana peels and corn cobs selected food ethanol ethanol wastes productivity (%/hr) concentration (%) collard greens 0.001820 a 0.1470 a banana peels 0.004326 b 0.3877 b corn cobs 0.006032 c 0.4787 c p value *** *** l.s.d (p<0.05) 0.000774 0.01507 ***= highly significant at p<0.001. l.sd = least significant difference among different substrates used. amounts of bioethanol produced from collard greens, banana peels and corn cobs were low as compared to studies of (utama et al., 2019) who reported 7.38% and 1.18% bioethanol from banana wastes and leafy vegetable respectively and (gawande and patil, 2017) who also reported 4.3% maximum ethanol from damaged corn grains. this variation is due to low amount of fermentable sugars present in collard greens, banana peels and corn cobs as compared to the whole banana fruit wastes and corn grains used. 3.2 effects of different fermentation times on ethanol production optimum fermentation time for maximum ethanol concentration and productivity for banana peels and collard greens was 48 hours. this is due to early entry of yeast cells into the exponential phase because of high initial inoculum of yeast suspension. the decrease in ethanol with increase in fermentation time can be attributed to the accumulation of inhibitors and toxic metabolic by-products during fermentation which affect yeast growth leading to decrease in yeast cell biomass (gawande and patil, 2017).reduction in their hydrolysate sugar levels as incubation time increases can also lead to decrease in bioethanol because availability © 2020 the authors. page 66 of 69 osei et. al. indonesian journal of environmental management and sustainability, 4 (2020) 64-69 figure 3. effects of different incubation times on ethanol concentration figure 4. effects of different incubation times on ethanol productivity of limited sugars causes progression of yeast cells into the stationary phase (braide et al., 2018). (sharma et al., 2007) reported decrease in bioethanol concentration after 48 hours using citrus and banana wastes. (arumugam and manikandan, 2011) also reported decrease in ethanol content after 48 hours of incubation from banana and mango wastes. a study by (gutierrez et al., 2015) reported decrease in ethanol percentage as fermentation time increased using ripe carabao mango peelings. the increase in ethanol concentration as incubation time increases in corn cobs is as a result of gradual increase in the number of yeast cells due to the availability of nutrients (tahir et al., 2010). (siddesh and kavya, 2019) reported increase in ethanol concentration as incubation time increases using corn and sugarcane bagasse feedstock. (akpan et al., 2008) also reported increase in bioethanol concentration with increase in incubation time from maize and old waste papers. decrease in ethanol productivity in corn cobs as seen from figure 4 is due to decrease in amount of substrate but increase in the amount of products which acts as inhibitory agent. (thapa et al., 2019) also reported increase in ethanol concentration with time but decrease in productivity. the optimum fermentation time for maximum ethanol concentration in corn cobs was 144 hours whilst 48 hours was optimum for maximum ethanol productivity. figure 5. effects of different incubation conditions on ethanol concentration 3.3 effects of different incubation conditions on ethanol production optimum incubation conditions for ethanol concentration in corn cobs, banana peels and collard greens were incubator (30oc), under soil (19oc) and dark room (21oc) respectively. yeast growth under different temperature conditions depends on the composition of the media (rainescasselman, 2005). low ethanol concentration from corn cobs hydrolysate under soil and dark room conditions as compared to incubator is due to the low temperatures in the soil and dark room and the presence of other unfavourable conditions causing stresses in yeast growth and fermentation performance. (kumar and tantwai, 2019) also reported maximum bioethanol content from corn wastes using an incubator set at temperature 30oc. for collard greens and banana peel substrates, dark room and biological conditions under the soil were favourable for their maximum ethanol production. also, abiotic factors like temperature, soil organic matter, ph, conductivity, availability of water and macronutrients like nitrogen, phosphorus, potassium, sodium and magnesium present in soils might have influenced proper yeast growth in their hydrolysates. their low ethanol production under incubator conditions at 30oc can be attributed to the process of heat formation occurring during glucose catabolism to ethanol might have caused a further increase in the set temperature leading to low yeast activity due to extremely high temperature (tiukova, 2014). aside heat formation, there can also be the possibility of 30oc temperature being extremely high for effective yeast growth and metabolism in their hydrolysates leading to low ethanol production. 4. conclusions findings from the study suggest that banana peels, corn cobs and collard greens can be used efficiently to produce bioethanol and is recommended that they are utilized instead of energy crops that threaten food security. the study has also proven the potential of incubation using soil and dark room and should therefore be incorporated as part © 2020 the authors. page 67 of 69 osei et. al. indonesian journal of environmental management and sustainability, 4 (2020) 64-69 table 3. effects of different incubation times on bioethanol concentration and productivity of selected food wastes products treatments incubation duration ethanol productivity ethanol concentration (hours) (%/hr) (%) collard greens 48 0.003479d 0.1670 c collard greens 96 0.001301b 0.1249b collard greens 144 0.000693a 0.0998 a banana peels 48 0.007390f 0.3547 f banana peels 96 0.003300d 0.3168 e banana peels 144 0.001881.c 0.2709d corn cobs 48 0.009467 g 0.4544 g corn cobs 96 0.004819 e 0.4626 g corn cobs 144 0.003251 d 0.4681 g p value *** *** l.s.d (p<0.05) 0.0003621 0.02212 ***= significant at p<0.001. l.sd = least significant difference among different substrates used table 4. effects of different incubation methods on bioethanol concentration of collard greens, banana peels and corn cobs treatments temperature ethanol (oc) concentration (%) collard greens 19 0.1346ab collard greens 21 0.1410b collard greens 30 0.1112a banana peels 19 0.3309d banana peels 21 0.3285d banana peels 30 0.2882c corn cobs 19 0.4533 e corn cobs 21 0.4564 e corn cobs 30 0.4678 e p value * l.s.d(p<0.05) 0.02529 *= significant at p<0.05 l.sd = least significant difference among different substrates used. *19oc= soil conditions; 21oc= dark room conditions; 30oc= incubator conditions. of incubation techniques for fermentation especially in low income countries. acknowledgement the research was supported by intra africa mobility program under european union. references akpan, u. g., a. a. alhakim, u. j. j. ijah, et al. (2008). production of ethanol fuel from organic and food wastes. leonardo electronic journal of practices and technologies, 7(13); 001–011 ali, a., z. abdul razaq, y. tlaiaa, and a. khishala (2016). methane biogas production from mixing of algae and municipal solid waste by anaerobic digestion. international journal of environmental research, 10(4); 613–624 arumugam, r. and m. manikandan (2011). fermentation of pretreated hydrolyzates of banana and mango fruit wastes for ethanol production. asian j. exp. biol. sci, 2(2); 246–256 azhar, s. h. m., r. abdulla, s. a. jambo, h. marbawi, j. a. gansau, a. a. m. faik, and k. f. rodrigues (2017). yeasts in sustainable bioethanol production: a review. biochemistry and biophysics reports, 10; 52–61 braide, w., i. oji, s. adeleye, and m. korie (2018). comparative study of bioethanol production from agricultural wastes by zymomonas mobilis and saccharomyces cerevisiae. international journal of applied microbiology and biotechnology research byadgi, s. a. and p. kalburgi (2016). production of bioethanol from waste newspaper. procedia environmental sciences, 35; 555–562 cutzu, r. and l. bardi (2017). production of bioethanol from agricultural wastes using residual thermal energy of a © 2020 the authors. page 68 of 69 osei et. al. indonesian journal of environmental management and sustainability, 4 (2020) 64-69 cogeneration plant in the distillation phase. fermentation, 3(2); 24 gashaw, a. and t. getachew (2014). fermentation of crop residues and fruit wastes for production of ethanol and its pre-treatment methods: a review. international ournal of research., 1(11); 2348–6848 gawande, s. and i. patil (2017). evaluation of damaged corn grains for fuel ethanol production. international journal of innovative research in science gutierrez, e. d., k. amul, r. m. carpio, and a. toledo (2015). effect of selected fermentation parameters on bioethanol production from ripe carabao mango (mangifera indica) peelings. asia pacific journal of multidisciplinary research, 3(4) kim, j. h., j. c. lee, and d. pak (2011). feasibility of producing ethanol from food waste. waste management, 31(9-10); 2121–2125 kumar, r. l. n. s., a. and k. tantwai (2019). bioethanol production from waste corn using saccharomyces cerevisiae and aspergillus awamori. international journal of current microbiology and applied sciences li, a. (2008). bioconversion of biodegradable municipal solid waste (bmsw) to glucose for bio-ethanol production. ph.d. thesis, university of london lohri, c. r., s. diener, i. zabaleta, a. mertenat, and c. zurbrügg (2017). treatment technologies for urban solid biowaste to create value products: a review with focus on low-and middle-income settings. reviews in environmental science and bio/technology, 16(1); 81– 130 moukamnerd, c., h. kawahara, and y. katakura (2013). feasibility study of ethanol production from food wastes by consolidated continuous solid-state fermentation. journal of sustainable bioenergy systems nair, r., p. r. lennartsson, and m. j. taherzadeh (2017). bioethanol production from agricultural and municipal wastes. in current developments in biotechnology and bioengineering. elsevier, pages 157–190 raines-casselman, m. 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(unpublished masters dissertation) davangere university, davangere, india. singh, a. and a. singh (2015). a comparative overview of bioethanol production from organic residues of agro waste materials. european journal of biotechnology and bioscience, 3(3); 11–14 syawala, d. s., t. wardiyati, and m. d. maghfoer (2013). production of bioethanol from corncob and sugarcane bagasse with hydrolysis process using aspergillus niger and trichoderma viride. journal of environmental science, toxicology and food technology, 5(4); 49–56 tahir, a., m. aftab, and t. farasat (2010). effect of cultural conditions on ethanol production by locally isolated saccharomyces cerevisiae bio-07. j. appl. pharm, 3(2) thapa, b., s. patidar, n. khatiwada, a. kc, and a. ghimire (2019). production of ethanol from municipal solid waste of india and nepal. in waste valorisation and recycling. springer, pages 47–58 tiukova, i. (2014). dekkera bruxellensis, a non-conventional ethanol production yeast, volume 2014. .(unpublished doctoral dissertation )university of agricultural sciences uppsala, sweden triana, c. f. (2016). towards improved ethanol production from lignocellulosic biomass. ph.d. thesis, ucl (university college london) utama, g. l., f. e. sidabutar, i. felina, d. w. wira, and r. l. balia (2019). the utilization of fruit and vegetable wastes for bioethanol production with the inoculation of indigenous yeasts consortium. bulgarian journal of agricultural science, 25(2); 264–270 woldesenbet, a. g., b. woldeyes, and b. s. chandravanshi (2016). bio-ethanol production from wet coffee processing waste in ethiopia. springerplus, 5(1); 1903 © 2020 the authors. page 69 of 69 introduction experimental section materials methods waste preparation and pre-treatment enzymatic saccharification preparation of yeast inoculum and fermentation procedure analytical procedure bioethanol analysis statistical analysis results and discussion bioethanol production at different incubation conditions and times effects of different fermentation times on ethanol production effects of different incubation conditions on ethanol production conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper interrelation of phytoplankton and water quality at bung binh thien reservoir, an giang province, vietnam nguyen thanh giao1*, truong hoang dan1 1department of environmental management, college of environment and natural resources, can tho university. 3/2 street, ninh kieu district, can tho city, viet nam *corresponding author e-mail: ntgiao@ctu.edu.vn abstract seasonal changes in water quality and phytoplankton composition in bung binh thien lake, an giang province were investigated in this study. nine samples were collected in the dry and rainy season in 2019 for analyzing the composition of phytoplankton and identifying the principal water quality factors influencing the phytoplankton. temperature, turbidity, ph, total suspended solid (tss), dissolved oxygen (do), biological oxygen demand (bod), chemical oxygen demand (cod), ammonium (n-nh+4 ), orthophosphate (p-po 3− 4 ) and coliforms were analyzed for water quality index (wqi) determination. the results indicated that five phyla of phytoplankton including bacillariophyta, chlorophyta, cyanophyta, euglenophyta and dianophyta were identified at the lake. species compositions of chlorophyta was the most abundant while dinophyta were found in limited numbers in the two seasons. however, bacillariophyta was the highest density thus dominating in the water through seasons. season resulted in strong influence on the phytoplankton, for example, density and shannon-wiener diversity index (h’) in the dry season were higher than those in the wet season. both h’ and wqi indexes revealed that water quality in the dry season was less polluted than that in the rainy season. canonical correspondence analysis (cca) showed that do, turbidity, tss and nutrients (p-po3−4 and n-n 3− o ) were the main factors affecting phytoplankton composition in the lake. this study provided important information on interrelation of phytoplankton composition and water quality parameters supporting water monitoring. keywords bung binh thien, cca, phytoplankton, water quality index, coliforms. received: 27 march 2020, accepted: 22 november 2020 https://doi.org/10.26554/ijems.2020.4.4.110-115 1. introduction the decline in surface water quality in rivers, lakes and some other water bodies occurs easily due to the relatively easily access to waste disposal (samarghandi et al., 2007). in recent years, the decline of water quality has stemmed from natural processes (flow characteristics, tidal regime, soil erosion, climate change, etc.) and human activities (use agricultural land, domestic activities and the discharge of wastewater from other activities) (gantidis et al., 2006); (arain et al., 2008). phytoplankton is one of the basic biological components of rivers and ponds, providing energy for higher plants through the food chain (li et al., 2019). thus, phytoplankton is a biological indicator that is relatively sensitive to changes in the aquatic environment. monitoring water environment could be implemented using physical, chemical characteristics of water or using diversity of phytoplankton. water quality index (wqi) and shannon-wiener diversity index (h’) are commonly used for water quality assessment and biodiversity measurement (gao and song, 2005). the application of multivariate techniques such as canonical correspondence analysis (cca) in assessing water quality and biodiversity has been widely applied for interpretation of environmental data feher et al. (2016); luu (2017); chounlamany et al. (2017). cca analysis could provide useful information regarding significant changes in species distribution due to water quality. several studies assessed the relationship between water quality and phytoplankton composition through cca analysis on dong nai and ba lai rivers (luu, 2017); (luu et al., 2017); however, there has been no such study at bung binh thien reservoir. this study was carried out to assess seasonal changes in water quality, phytoplankton diversity and examine the water quality parameters determine the diversity of phytoplankton. the findings from this study could be a useful information for water environment monitoring. https://doi.org/10.26554/ijems.2020.4.4.110-115 nguyen and dan indonesian journal of environmental management and sustainability, 4 (2020) 110-115 figure 1. map of sampling sites 2. methodology 2.1 study area binh thien bung is one of the largest freshwater reservoirs in the vietnamese mekong delta with the water surface area in the dry season is 200 ha and 800 ha in dry and wet season, respectively. the average depth of the reservoir is approximately 3.5 m in the dry and the highest is 6 m in the flood season (for environment monitoring and giang, 2012). the reservoir receives freshwater from the binh di river on a regular basis. agriculture (growing rice, vegetables, and fruits) and aquaculture (raising fish) are the two main activities of people around the reservoir. water in the reservoir mainly serves for domestic activities, irrigation and recreation of the local people and visitors. however, the reservoir is also strongly affected by wastes generated by natural processes (water regime, erosion, weather conditions) and anthropogenic activities (domestic activities, agricultural production, aquaculture, and tourism activities). these activities could seriously influence on water quality and phytoplankton in the reservoir. 2.2 water sampling and analysis to evaluate quality of water, surface water and phytoplankton samples were simultaneously collected in the dry (march, 2019) and rainy seasons (september, 2019) at nine sites in the reservoir as indicated in figure 1 . ten water quality parameters comprising temperature, turbidity, ph, total suspended solid (tss, mg/l), dissolved oxygen (do), biochemical oxygen demand (bod), chemical oxygen demand (cod), ammonium (n-nh+4 ), orthophosphate (p-po 3− 4 ) and coliforms. temperature, turbidity, ph and do were immediately measured at the field using handheld meters. the other water variables were analysed using the methods in standard methods for the examination of water and wastewater (apha, 1998). the water quality index (wqi) was calculated according to decision 879/qd –tcmt of vietnam environment administration using equation (1): wqi = wqiph 100 [ 1 5 5∑ a=1 wqia. 1 2 2∑ b=1 wqib.wqic ]1/3 (1) where wqia is wqi calculated for do, bod, cod, nnh+4 , p-po 3 4-; wqib is wqi calculated for tss, turbidity; wqic is calculated for coliforms; wqiph is wqi calculated for ph (ph ranged from 6 – 8.5). according to the decision 879/qd-tcmt, water qualitiy is divided into five levels based on the values of wqi. level 1 (91 < wqi < 100) indicates clean water quality which is used well for domestic purposes. level 2 (76 < wqi < 90), good water quality which is suitable for a living but appropriate treatment is needed. level 3 (51 < wqi < 75) is used for irrigation and equivalent purposes, water quality is moderate pollution. level 4 (26 < wqi < 50) indicates polluted water only suitable for navigation. finally, level 5 (0 < wqi < 25) heavily polluted water requires future remedies. 2.3 phytoplankton sampling and analysis for phytoplankton, phytoplankton qualitative specimens were collected by net with a mesh size of 25 µm. quantitative sampling was collected by filtering 100 litres of water through the phytoplankton net. after that, the samples were stored in 110 ml vials and fixed with formaldehyde (to the final concentration of 2-4%. qualitative analysis samples were observed and classified according to tien and hanh (1997), ho (1972), reynolds (2006), brierley et al. (2007), suthers et al. (2019a). quantitative analysis was performed by counting individuals of the phytoplankton followed the method of (boyd and tucker, 1992). the density of phytoplankton was calculated by equation 2: y = x ∗ vcd ∗ 1000 n ∗ a ∗ vtt (2) in which y is the individual of phytoplankton per liter of sample (individuals/liter); x is the numbers of individuals counted; vc is the volume of the concentrated sample (ml); n is the numbers of counting cells; a is the counting cell area (1 mm2) and vtt is volume of collected water (ml). the shannon wiener diversity index (h’) was used to assess the diversity of phytoplankton in the study area and was calculated by the equation (3): h′ = − ∑ pi.ln(pi) (3) where pi=ni/n; ni is the number of individuals in the sample; n is total amount of individuals in the samples. the rating scale of water quality by h ’index (henna & rya © 2020 the authors. page 111 of 115 nguyen and dan indonesian journal of environmental management and sustainability, 4 (2020) 110-115 sunoko, 1995) is mentioned in 5 different levels of pollution: very polluted (h’ <1), polluted (1 <h’ <2), mild pollution (2 <h’ <3), good (3 <h’ <4.5) and very good (h’ >4.5). 2.4 data processing similarity percentage analysis (simper) and canonical correspondence analysis (cca) were applied in this study. simper analysis was performed to determine the dominance and contribution of each species to the diversity in the study area. simper was performed using primer 5.2 for windows (primer-e ltd, plymouth, uk). phytoplankton composition data for analysis were the dominant species with a contribution level of over 5% through the simper multivariate analysis technique (thai, 2018). canonical correspondence analysis (cca) was used to find the main water quality parameters affecting change of phytoplankton species. the direction of the arrow indicated positive and negative correlation and their length corresponds to the importance of the explanatory variable in the graph (jasprica et al. (2012); laskar and gupta (2013)). the relationship between water quality variables and the abundance of phytoplankton in this study was determined by the past (paleontological statistics) version 3.06. 3. results and discussion 3.1 seasonal variations of phytoplankton the results showed that 273 species belonging to five phyla including chlorophyta (83 species), euglenophyta (60 species), bacillariophyta (59 species), cyanophyta (42 species) and dinophyta (29 species) were found in the dry season, (figure 2). meanwhile, 146 species comprising chlorophyta (53 species), bacillariophyta (30 species), euglenophyta (28 species), cyanophyata (27 species) and dinophyta (8 species) were discovered in the wet season (figure 2). there was a significant change in the species composition due to seasonal shift. this could be due to the difference in intensity of incident light and water temperature (abrantes et al. (2006); ke et al. (2008)). previous studies only found 66 species belonging to seven phyla (quyen, 2015) and 85 species belonging to six phyla toan (2014) which were much lower in species composition compared to this study. however, the former and the current studies have found that chlorophyta was the dominant phylum in the reservoir in dry and wet season. this phylum of algae is representative for the algal group occurred frequently in freshwater bodies and indicated for moderate water pollution (wu, 1984). the density of phytoplankton was found to be seasonally varied (figure 2). the densities of algae inside the reservoir (vt1-vt8) in the dry season varied from 41,048 to 121,452 individuals/l and averaged at 81,250 individuals/l. the algal densities ranged from 1,275 to 38,389 individuals/l (averaged at 19,832 individuals/l) in the rainy season. as can be seen that less diversity of phytoplankton was found in the rainy season. the lower density of phytoplankton was also reported in the previous studies (thai (2018); hoang (2009); figure 2. seasonal variation of phytoplankton quyen (2015); toan (2014); li et al. (2019)). phytoplankton density in the bung binh thien reservoir (vt1-vt8) was higher than those in binh di river (vt9). it was also higher than the densities of phytoplankton in certain water segments in hau river, for example, hau river in an giang section (7,868 47,155 individuals/l, in dry season) dat (2014) and hau river in can tho section (12,620 284,294 individuals/l in the dry season; 667 4,940 individuals/l in the rainy season) (quy and luu, 2011). composition and density of phytoplankton bung binh thien reservoir in the dry season tended to be higher than those in the rainy season which could be explained that the high flow rate in the rainy season resulted in disturbing water quality due to suspended solids egborge (1994), nutrient dilution and light penetration limit for phytoplankton production (gosselain et al., 1994; sowunmi (2001)). 3.2 water quality assessment using h’ and wqi the variation of species composition and the number of phytoplankton species are proportional to the variation of shannon-wiener diversity index (h’). the calculation showed that h’ ranged from 1.12 2.71 (figure 3). the values of h’ in the dry season indicated that water environment was slightly polluted (h’ > 2). there was a significant shift in water quality from the dry to the wet season. the values of h’ were in the range of 1< h’ <2 indicated moderate water pollution. the water quality index (wqi) in the bung binh thien reservoir ranged from 57 88 (in the dry season) and 11 79 (in the rainy season) (figure 4). based on wqi, water quality in the dry season was suitable for domestic use but appropriate measures are required (level 2), except for the locations vt8 and vt9 only suitable only for irrigation or © 2020 the authors. page 112 of 115 nguyen and dan indonesian journal of environmental management and sustainability, 4 (2020) 110-115 figure 3. seasonal change of shannon-wiener diversity index (h’) at the sampling sites figure 4. seasonal change of water quality index (wqi) at the sampling sites equivalent purposes (level 3). however, the values of wqi in the rainy season indicated that the water was from slight (vt3, vt5) to moderate pollution (vt2, vt4, and vt7). the remaining locations (vt1, vt6, vt8) were classified as heavy pollution (wqi=13-72). 3.3 environmental factors affecting phytoplankton simper analysis was performed to identify the dominance and representative species of phytoplankton for each season (table 1). among the occurred phytoplankton species, nitzschia longissima, melosira granulata and oscillatoria muticola were the three dominant species in dry season, while melosira granulata, melosira granulata var. valida and coscinodiscus rothii were identified as the species that frequently appeared in the samples during the rainy season. it was found that melosira species occurred abundantly in both seasons and this observation was similar to the study of (ogbuagu and ayoade, 2012). simper analysis results indicated that only 20 species appeared regularly and dominated in both seasons out of 273 species in the dry season and 146 species in the rainy season (table 1). cca analysis was used to show the relationship of environmental parameters and composition of phytoplankton in the study area. the results of cca analysis in the dry season were based on 10 water quality parameters and 6 dominant phytoplankton species. from figure 5a, it can be seen that the value of eigenvalues constant and the percentage of difference were relatively large between axis 1 and axis 2, in which axis 1 explained figure 5. cca analysis in dry season (a) and rainy season (b) 74.26% (0.21) and axis 2 explained 16.33% (0.05). in the dry season, do and po3−4 -p were the two most pivotal factors affecting species composition in bung binh thien lake. this was followed by organic matter (bod and cod), turbidity and coliform, and the final was temperature, ph, tss and nh+4 -n. some species were highly correlated with axis 1 such as melosira granulata, aphanocapsa pulchra and oscillatoria muticola. melosira granulata, aphanocapsa pulchra were found to be positively correlated with do and organic matter; however, oscillatoria muticola was positively correlated with phosphate, turbidity and coliform. note: anabaena variabilis – av, aphanocapsa pulchra – ap, chodatella chodatii – chc, coscinodiscus rothii – cr, cyclotella comta – cc, diatoma elongatum – de, glenodinium penardiforme – gp, melosira granulata – mg, melosira granulata var. valida – mgv, navicula lyra – nl, nitzschia brebissonii – nb, nitzschia longissima – nl, oscillatoria guttulata – og, oscillatoria limosa – ol, oscillatoria muticola – om, pediastrum simplex – ps, scenedesmus quadricauda – sq, surirella robusta var. splendida sr, trachelomonas hispida – th, trachelomonas volvocina –tv. in the rainy season, the first two axes explained 95.80% of the relationship between the two factors (axis 1 accounted for 89.53%, axis 2 accounted for 6.27) with eigenvalues of 0.43 and 0.03, respectively. navicula lyra, coscinodiscus rothii, diatoma elongatum, surirella robusta var. splendida, trachelomonas volvocina and trachelomonas hispida showed a positive correlation with axis 1 (figure 5b). the distribution of these species was recorded as being affected and positively correlated with the factors of decreasing levels such as turbidity, tss, nh+4 -n and p-po 3− 4 . in addition, from the analysis of simper and cca, the presence of anabaena variabilis, cyclotella comta, pediastrum simplex glenodinium penardiforme, scenedesmus quadricauda, melosira granulata and oscillatoria limosa were found to be affected by © 2020 the authors. page 113 of 115 nguyen and dan indonesian journal of environmental management and sustainability, 4 (2020) 110-115 the season. previous studies have also shown that the parameters such as tss, temperature, ph and nutrients play a crucial role in forming the species composition of an area (luu et al. (2017); suthers et al. (2019b)). similar to the previous studies, the rapid change in physicochemical factors between the two seasons (especially do, tss, turbidity and nutrients) in bung binh thien reservoir could lead to major changes in the composition and quantity of phytoplankton. 4. conclusions phytoplankton species in bung binh thien reservoir was found to be 283 species (dry season) and 146 species (rainy season), belonging to five phyla bacillariophyta, chlorophyta, cyanophyta, euglenophyta and dianophyta. in particular, chlorophyta dominated species composition in both seasons. the average density of the individuals in dry season was around 81,250 individuals/l, while in the rainy season was only about 19,832 individuals/l. diversity indexes h’ and wqi fluctuated between 1.12 2.71 (dry season) and 1.35 2.44 (rainy season); 57 88 (in the dry season) and 11 79 (in the rainy season). the findings showed that the diversity of phytoplankton in the dry season was higher than that in the rainy season and the shift in phytoplankton diversity was closely related to water quality index. the results of cca analysis showed that the composition of phytoplankton was affected by do, tss, turbidity, n-nh+4 , and p-po 3− 4 . melosira granulata and oscillatoria muticola were found to be influenced by the environmental factors in the dry season while coscinodiscus rothii, diatoma elongatum, surirella robusta var. splendida were environmentally affected in the rainy season. references abrantes, n., s. antunes, m. pereira, and f. gonçalves (2006). seasonal succession of cladocerans and phytoplankton and their interactions in a shallow eutrophic lake (lake vela, portugal). acta oecologica, 29(1); 54–64 apha (1998). standard methods for the examination of water and wastewater. washington, dc standard methods for the examination of water and wastewater arain, m., t. kazi, m. jamali, n. jalbani, h. afridi, and a. shah (2008). total dissolved and bioavailable elements in water and sediment samples and their accumulation in oreochromis mossambicus of polluted manchar lake. chemosphere, 70(10); 1845–1856 boyd, c. e. and c. s. tucker (1992). water quality and pond soil analyses for aquaculture. water quality and pond soil analyses for aquaculture chounlamany, v., m. a. tanchuling, and t. inoue (2017). spatial and temporal variation of water quality of a segment of marikina river using multivariate statistical methods. water science and technology, 76(6); 1510–1522 dat, p. 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(2014). species composition and density of algae in bung binh thien. master’s thesis, can tho university © 2020 the authors. page 115 of 115 introduction methodology study area water sampling and analysis phytoplankton sampling and analysis data processing results and discussion seasonal variations of phytoplankton water quality assessment using h’ and wqi environmental factors affecting phytoplankton conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper toxic and hazardous (b3) solid waste management at abdul moeloek general hospital: an implementation assessment in 2022 and recommendations sillak hasiany1*, riadi tomson eventius naibaho1, yuni lisafitri1, intan andriani putri2 1environmental engineering, sumatera institute of technology, jl. terusan ryacudu, way huwi, kecamatan jati agung, kabupaten lampung selatan, lampung, 35365, indonesia 1geophysical engineering, sumatera institute of technology, jl. terusan ryacudu, way huwi, kecamatan jati agung, kabupaten lampung selatan, lampung, 35365, indonesia *corresponding author e-mail: hasiany.siregar@tl.itera.ac.id abstract making sure that the health and environment are taken care of, solid b3 waste produced by hospitals has to be treated according to existing regulations. as an a-class hospital in bandar lampung, am general hospital commit to conducting good practices for its solid b3 waste management. this study aims to analyze the current implementation of solid b3 waste management, the compliance of am general hospital’s b3 waste management standard operation procedure (sop) with current regulations, and recommend improvement strategies for solid b3 waste management in am general hospital. for eight consecutive days in august 2022, solid b3 waste samples were collected and analyzed. the average solid b3 waste produced by am general hospital was 285 kg/day for infectious waste and 6.3 kg/day for sharp waste. inpatient installation contributed the majority of solid b3 waste there. due to the observation sheet that was created according to the regulations, 65% of am general hospital’s sop involving sorting; storage; collection; transportation; and disposal has already complied with the regulations. several shortcomings were found such as the absence of an official solid b3 waste handling report; the absence of proper labeling in the b3 waste containers; and the use of black plastic bags. analytical hierarchy process (ahp) data analysis technique was deployed, resulting in a technology application and waste minimization as improvement recommendations. keywords solid b3 waste management, hospital, assessment, ahp, sop received: 10 december 2022, accepted: 18 march 2023 https://doi.org/10.26554/ijems.2023.7.1.32-37 1. introduction 15% of the total amount of waste produced by healthcare activities is considered hazardous material that may be infectious, toxic, or radioactive (world health organization, health-care waste). general hospital is a vital facility in supporting citizens’ health care which produces solid hazardous and toxic waste or so-called solid b3 waste that could cause serious infection and poses a potential threat to the surrounding environment, to the public in general, and the person handling it (freeman, 1989). solid b3 waste generated from hospitals includes hypodermic needles, blades, scalpels, gloves, surgical cotton, bandages, discarded medicine, clothes, body fluids, human tissues and organs, chemicals, etc (radha et al., 2009). good practices of b3 waste management could be implemented with the support of policies such as regulatory documents, sops, and comprehensive work instruction based on regulations (hutajulu et al., 2022). poor management of solid medical waste in hospitals can endanger the health and the environment. this can cause all hospital workers, medical waste handlers, and the public to be exposed to infection, toxic effects, and injury (wilhemina et al., 2022). based on the potential hazards of medical waste, the types of waste can be classified into infectious, non-infectious, body tissue, cytotoxic, and pharmaceutical waste. infectious waste may contain various types of pathogenic microorganisms that can enter the human body through several ways such as punctures, cuts or skin wounds, mucous membranes, respiration, or ingestion. sharp objects not only can cause scratches or puncture wounds but can also infect wounds if the object is contaminated with pathogens. due to these risks (injury and disease transmission), sharp objects are classified as highly dangerous waste (alam et al., 2019). https://doi.org/10.26554/ijems.2023.7.1.32-37 hasiany et. al. indonesian journal of environmental management and sustainability, 7 (2023) 32-37 abdul moeloek general hospital (am hospital) is a crucial a-class hospital in bandar lampung. the latest study in 2019 concluded that am hospital’s solid b3 waste management has not met the regulation of the indonesian ministry of health regulation 1204 2004 yet (tarigan, 2019). awareness of solid b3 waste management’s necessity was low. moreover, combustion could not be performed because the incinerator device did not work well. therefore, this research is conducted to analyze the existing condition of solid b3 waste management at ah hospital, to assess the compliance of am general hospital’s sop with existing regulations, and to recommend a strategic action plan to improve solid b3 waste management further. according to the indonesian ministry of health regulation no. 7/2019, solid b3 waste management is a series of activities that include sorting, collection, transportation, storage, management, and disposal of medical waste. this article also highlights the important elements of medical waste management in hospitals, which include waste minimization, labeling and packaging, transportation, storage, management, and disposal. a validity test is used to measure the validity of a questionnaire. a questionnaire is said to be valid if the questions on the questionnaire are able to reveal something that will be measured by the questionnaire. one of the most commonly used formulas is pearson’s correlation coefficient formula. the significance test from n data is done by comparing the value of the reference and calculated pearson coefficient correlation (r) using the following equation 1: r = ∑ xy − ∑ x ∑ y n ( ∑ x2 − ( ∑ x)2 n )( ∑ y2 − ( ∑ y)2 n ) (1) cronbach alpha (α) is one of the testing methods for reliability. one variable is said to be reliable when its value is more than 0.6. the value could be calculated using the following equation 2: rx = ( n n − 1 ) ( 1 − ∑ σt2 σt2 ) (2) with rx standing for reliability value, n is the number of questions, and σ is variance. general hospital bandar lampung general hospital as the research material on august 2022 for eight consecutive days. the primary data was collected through observations, interviews, questionnaires, and documentation. the observation was conducted to obtain a visual representation of the waste management process, while interviews and questionnaires were conducted to obtain the opinions and experiences of hospital staff. the secondary data was obtained from am general hospital bandar lampung documentation and literature studies. the documentation review focused on the waste management policy and procedures, while literature studies were conducted to obtain information on best practices and regulations on solid medical waste management. 2. experimental section this study utilized a mixed-methods approach to investigate solid medical waste management in hospitals. this study was conducted by following the flowchart presented in figure 1. the literature study was conducted to learn about current regulations and some legal documents of am general hospital. instrument testing in this study was performed on each statement item, which consisted of 7 statements from 30 respondents. the validity test in this study used the spss application. figure 1. research flow chart the significance value of all 7 statements was more than 0.05 which means all of the statements were valid. the reliability test was done using cronbach alpha (equation 2) resulting reliability coefficient equal to 0.915 which means that all of the questions were reliable. solid b3 waste sample was collected on august 2022 for eight consecutive days. 3. results and discussion 3.1 current condition of solid b3 waste management at am general hospital solid b3 waste management at am general hospital is carried out under the environmental health unit. the main responsibility of this unit is to develop and implement hospital sanitation programs based on the decision of the am general hospital director number 180/01.h/vii.02/7.2/vii/2020 regarding the establishment of the hospital’s environmental health installation. the organizational structure of the environmental health unit is shown in figure 2. © 2023 the authors. page 33 of 37 hasiany et. al. indonesian journal of environmental management and sustainability, 7 (2023) 32-37 figure 2. the organizational structure of the environmental health unit the schematic workflow of solid b3 waste management is shown in figure 3. solid b3 waste management activities have been carried out at am general hospital by separating recyclable medical waste such as infusion bottles and outworn hemodialysis fluid bags for washing and disinfection processes at the 3r waste management facility. the procedure follows the ministry of environment and forestry regulation no. p.56 of 2015. sorting is done by separating medical and non-medical waste. solid b3 wastes are divided into infectious waste and sharp medical waste. sharp waste is collected using safety boxes, while infectious waste is collected using yellow-colored plastic bags. solid b3 waste is collected every morning and evening or as needed by the cleaning service staff. the process of collecting and transferring solid b3 waste is done by carrying the waste container on a trolley to the lb3 waste management facility. based on observations, the lb3 facility is able to accommodate waste produced for temporary storage before it is transported. transportation and disposal of solid b3 waste at am general hospital in bandar lampung are carried out by a third party, pt. universal eco pacific. the cooperation between am general hospital in bandar lampung and the waste transport/disposal service provider is based on a work contract. based on observations and respondent interviews, the waste transporters from pt. universal eco pacific comes with a special solid b3 waste vehicle to collect solid b3 waste three times a week: on tuesdays, thursdays, and saturdays, from 9 am to 12 pm western indonesia time. the vehicle used is a suitable and enclosed box truck with b3 symbols and the transporter company’s identity on the vehicle. the staff from pt. universal eco pacific and am general hospital in bandar lampung use personal protective equipment such as masks, gloves, long clothes, and boots. figure 3. schematic diagram of solid b3 waste management at am general hospital 3.2 solid b3 waste amount, composition, and sources based on the data in table 1, solid b3 waste at am general hospital is divided into two categories, they are infectious waste and sharp objects waste originating from medical activities. the dominant compositions of infectious medical waste generated in public hospitals was infectious waste, sharps, and pathological wastes (lemma et al., 2022). most of the solid b3 waste consists of medical equipment and materials as well as personal protective equipment (ppe) that are exposed to chemicals or residue from patient care. table 1. solid b3 waste categories and its items solid b3 waste category solid b3 waste item sharp objects waste syringes, vial bottles, iv needles infectious waste masks, iv bags, blood bags, gauze, gloves, headcovers, and aprons source: observation results, 2022 just like in another study, the quantity of solid b3 waste before disposal was weighted (tsakona et al., 2007). the © 2023 the authors. page 34 of 37 hasiany et. al. indonesian journal of environmental management and sustainability, 7 (2023) 32-37 figure 4. the daily average weight of infectious waste from each source at am general hospital figure 5. the waste generation percentage overlaid by number of patience from each source at am general hospital measurement of solid b3 waste was conducted on the basis of the indonesian national standard called sni 19-36941994 to obtain the average daily weight of each source of infectious and sharp objects waste at am general hospital bandar lampung, as shown in figure 4. the infectious waste is grouped by the management room, including inpatient, outpatient, surgery, emergency installation, and hospital support activities such as laboratory installations, central sterile supply department (cssd) installations, and laundry installations. the total average weight of infectious waste at am general hospital is 285 kg/day, where the largest source of medical waste is from the inpatient unit at 201 kg/day (70%), while the smallest source is from cssd and laundry installations by 3 kg/day (2%). this is supported by the number of patient data served by each management unit as shown in figure 5. several factors affect the amount of medical waste generated by each unit such as the level of medical service, the average daily number of visits, the type of disease, the number of medical staff, and the number of inpatients in the hospital (wisaksono, 2001). this is also confirmed by askarian et al. (2004) who states that the factors affecting the generation of solid b3 waste in hospitals include occupancy rates, types of medical treatment, and the number of patient visits. the inpatient unit is the largest source of medical waste generators because it has the second largest number of patients, 24 patients per day on average. they also provide more medical treatments than other units. it is also confirmed by osman et al. (2023) that in terms of waste quantities the unit with the highest generation waste was the inpatients. the outpatient unit has a large number of patients but generates less waste because the unit only performs diagnostic examinations. the cssd unit is responsible for sterilizing medical equipment in am general hospital bandar lampung. meanwhile, the waste generated by the laundry unit consists of personal protective equipment used in laundry activities. as for the laboratory, it rarely receives patients/ samples, so the medical waste it generates is also minimal. 3.3 the compliance level of solid b3 waste management at am general hospital the analysis of the implementation of solid b3 waste management at am general hospital was done on the basis of minister of health regulation number 7 of 2019 and the requirements of minister of environment and forestry regulation number: p.56/menlhk-setjen/2015. there are 5 management categories with 38 indicators. compliance level assessment of solid b3 waste management at am general hospital according to the total score in each category of management is presented in figure 6. figure 6. compliance level of am general hospital for each management category in figure 6, the compliance level of the sop aspect and processing aspect is 100% indicating that am general hospital has implemented medical solid waste management according to current regulations. the storage aspect has the lowest compliance indicator level (50%), it is categorized as moderately compliant. this is due to the non-compliance of medical waste management in 5 out of a total of 10 indicators: storage location; storage of solid b3 waste according to solid b3 waste groups; storage of solid b3 waste using containers according to the group and characteristics of the waste; bag’s color selection according to the characteristics of solid b3 waste; and the provision of solid b3 waste symbols and labels © 2023 the authors. page 35 of 37 hasiany et. al. indonesian journal of environmental management and sustainability, 7 (2023) 32-37 table 2. priority weights of aspects in selecting alternative medical waste management aspect aspect’s weight alternative weight of management attempt waste minimization recycling technology application policy 0.18 0.18 0.11 0.72 environmental health 0.71 0.37 0.36 0.27 financial 0.10 0.71 0.08 0.21 total weight 0.37 0.28 0.35 priority 1 3 2 table 3. improvement recommendation of solid b3 waste management alternative waste management strategies recommendations using a digital thermometer can reduce hazardous waste if a mercury thermometer is damaged (smale et al., 2021) not using aerosol air fresheners and identify appropriate vials sizes to use, and implement dose rounding of biologic and cytotoxic agents to decrease medication waste (afanasjeva and gruenberg, 2019) waste minimization centralizing and monitoring the flow/distribution of chemicals/hazardous waste according to their characteristics and types (aprilia, 2019) ensuring the expiration dates of products and medicines when delivered by suppliers (wardhani and kamil, 2020) avoiding the use of materials that contain hazardous and toxic substances (smale et al., 2021) application of conducting internal processing using an incinerator (osman et al., 2023) technology choosing an incinerator with good air pollution control recycling sorting medical waste that can be recycled on each bag or container according to the characteristics of solid b3 waste. a lack of coding and labeling system for the different categories of hospital waste affects the efficiency of collection and handling and the integrity of the final waste treatment processes (adu et al., 2020). the processing and collectiontransportation aspects have compliance indicator values of 60% or moderately compliant, indicating non-compliance with the indicators in both aspects. in the processing aspect, there were indications of non-compliance in waste containers that were not equipped with b3 labels and symbols and waste bags that were too full and could not be tied with one knot. non-compliance was also found in the collectiontransportation aspect, where solid b3 waste collection was not accompanied by a waste delivery note, the transport vehicle had a different license plate number than the document stated, and there was no special route for solid b3 waste collection. a special route is needed to provide safety for people and environment while transporting medical waste to disposal (agrawal et al., 2021). overall, the level of compliance with solid b3 waste management implementation at am general hospital bandar lampung with existing regulations of all aspects is 65%. 3.4 strategic plan to improve the quality of medical solid waste management at am general hospital the analytical hierarchy process (ahp) method was chosen as a method to determine priorities in selecting alternative medical solid b3 waste management at am general hospital. the aspects measured for determining priorities are policy, environmental health, and financial aspects. the selection of medical solid waste management alternatives is divided into three categories: waste minimization, recycling, and technology application. based on the results of ahp calculations, weights, and priorities are obtained for each aspect in determining alternative medical solid waste management at am general hospital bandar lampung (table 2). the table above shows that the environmental health aspect has the highest weight of 0.71 compared to the policy and financial aspects in determining the selection of alternatives for improving the management of solid b3 medical waste. to measure the priority of alternative medical waste management options, paired comparisons were made between the alternatives and the aspects of policy, environmental health, and financial, resulting in a total weight for each alternative. the total weight value determines the © 2023 the authors. page 36 of 37 hasiany et. al. indonesian journal of environmental management and sustainability, 7 (2023) 32-37 priority for selecting alternative efforts to manage hazardous waste at am general hospital, where the first priority is waste minimization with a weight of 0.37. the second priority is the technology application alternative with a weight of 0.35, and the third priority is the recycling alternative with a weight of 0.28. the efforts to improve the management of solid b3 waste based on the priority of alternative waste management options can be seen in the following table 3. 4. conclusions the source of solid b3 waste at am general hospital comes from various service units, and the characteristics of the generated solid b3 waste are infectious waste and sharp object waste. the generation rate of infectious waste is 285 kg/day and the generation rate of sharp object waste is 6.3 kg/day. the level of compliance with the standard operating procedure (sop) at am general hospital is 80%. the level of compliance of sop with the applicable regulations is 80%. meanwhile, the level of compliance with the applicable regulations is 65%. based on the alternative calculation of solid medical waste management at am general hospital bandar lampung using the ahp method, the recommended alternative is waste minimization and technology application. 5. acknowledgement we would like to express our gratitude to abdul moeloek general hospital who provided us with the data and permission to publish this research. references adu, r. o., s. f. gyasi, d. k. essumang, and k. b. otabil (2020). medical waste-sorting and management practices in five hospitals in ghana. journal of environmental and public health, 12; 1–14 afanasjeva, j. and k. gruenberg (2019). pharmacists as environmental stewards: strategies for minimizing and managing drug waste. sustainable chemistry and pharmacy, 13; 100164 agrawal, p., g. kaur, and s. s. kolekar (2021). investigation on biomedical waste management of 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(1989). standard handbook of hazardous waste treatment and disposal. new york, ny (us); mcgraw-hill book co. hutajulu, s. m., i. marsaulina, f. a. siregar, and s. m. indirawati (2022). solid medical waste management strategy in hospitals, indonesia. the open public health journal, 15(1); 1–7 lemma, h., l. asefa, t. gemeda, and d. dhengesu (2022). infectious medical waste management during the covid-19 pandemic in public hospitals of west guji zone, southern ethiopia. clinical epidemiology and global health, 15; 101037 osman, a. m., z. ukundimana, f. b. wamyil, a. a. yusuf, and k. telesphore (2023). quantification and characterization of solid waste generated within mulago national referral hospital, uganda, east africa. case studies in chemical and environmental engineering; 100334 radha, k., k. kalaivani, and r. lavanya (2009). a case study of biomedical waste management in hospitals. global journal of health science, 1(1); 82–88 smale, e. m., t. c. egberts, e. r. heerdink, b. j. van den bemt, and c. l. bekker (2021). waste-minimising measures to achieve sustainable supply and use of medication. sustainable chemistry and pharmacy, 20; 100400 tarigan, a. (2019). evaluation of medical solid waste management system at rsud abdul moeloek bandar lampung in 2018. esa unggul undergraduate theses of public health, indonesia (in indonesia) tsakona, m., e. anagnostopoulou, and e. gidarakos (2007). hospital waste management and toxicity evaluation: a case study. waste management, 27(7); 912–920 wardhani, e. and f. a. kamil (2020). pengelolaan limbah b3 di rumah sakit gigi dan mulut universitas padjadjaran kota bandung. jurnal serambi engineering, 5(4); 1443–1451 (in indonesia) wilhemina, a., p. amedumey, and g. b. h. raphael (2022). solid waste management in hospitals: a comparative assessment in some selected hospitals in obuasi municipality of ghana. cleaner waste systems, 3; 100025 wisaksono, s. (2001). characteristics of hospital waste and their impact on health and the environment. cermin dunia kedokteran, 130; 58–61 (in indonesia) © 2023 the authors. page 37 of 37 introduction experimental section results and discussion current condition of solid b3 waste management at am general hospital solid b3 waste amount, composition, and sou-rces the compliance level of solid b3 waste management at am general hospital strategic plan to improve the quality of medi-cal solid waste management at am general hospital conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper assessment of toxicological effects of triclosan on microbes, plants, and genetic material in cells merry krisdawati sipahutar1* 1occupational safety and health study program, faculty of vocation, balikpapan university, balikpapan, east kalimantan, 76114, indonesia *corresponding author e-mail: merry.k@uniba-bpn.ac.id abstract triclosan is an antiseptic ingredient that is commonly found in numerous personal care items that may end up in the environment. their ecotoxicological profile, however, is still unknown. the current research aims to determine the toxicity of triclosan on e. coli, vigna radiata and crotalaria juncea seeds, and allium cepa roots. the analyses include toxicity assays for microbes, phytotoxicity, and cytogenotoxicity. the results proposed if the triclosan tested (60-150 µm) became exceedingly harmful to the test bacterium, as seen by the decrease in e. coli cfu, indicated that triclosan had antibacterial properties and inhibited the test microbe, depending on the concentration of triclosan used. triclosan at concentrations of 40 and 80 µm, respectively, decreased the sprouting length of vigna radiata and crotalaria juncea by 45-50% and 70-72%, respectively. thus, the cytogenotoxicity assay using allium cepa revealed that triclosan damages the meristematic cells. triclosan at 40 µm concentration resulted in a 1.2% aberration index and a 10.4% mitotic index, and 80 µm caused a 1.4% aberration index and an 8.8% mitotic index. all of the findings point to triclosan being potentially hazardous to the biota. keywords triclosan, microbial toxicity, phytotoxicity, cytogenotoxicity received: 14 january 2023, accepted: 11 may 2023 https://doi.org/10.26554/ijems.2023.7.2.56-61 1. introduction the properties of triclosan as an antibacterial, antifungal, and antiviral agent make it widely utilized in a diversity of things for private care, synthetic goods, underware, and toys (barman et al., 2022; chen et al., 2023). triclosan has the iupac id c12h7cl3o2 and the chemical formula 5-chloro2-(2,4dichlorophenoxy)phenol. this compound migrates into the environment after being poured into the wastepipe and into the sewage system when used for such a broad range of daily requirements (nakagawa et al., 2022; heidler and halden, 2007). triclosan is an extremely poisonous substance, but despite this, it is frequently employed in the manufacturing of plastics, textiles, and personal care items. it is persistent and does not break down quickly (paul et al., 2010). the primary biodegradation of the substance takes weeks to months for complete biodegradation (balakrishnan and mohan, 2021). typically, 0.1% to 0.3% (w/w) of triclosan exists in products for private care (lu et al., 2009). at these concentrations, it displays broad-spectrum bacteriostatic action and an excellent human safety profile (dann and hontela, 2011). the molecular weight of triclosan is 289.6, it has a pka value of 8.14, and its logarithm of the octanol-water severance coefficient (log kow) is 4.8. it is hydrolytically stable, with a solvency of 12 mg/l at 20°c, and a haze pressure of 7×10-4 pa at 25°c (baalbaki, 2017). around 1500 tons of triclosan are generated universally every year (sui et al., 2017). due to the ineffective removal of the compound (72–93%) by traditional systems, a sizable proportion of triclosan is used in the treatment of wastewater and is inevitably released into aquatic areas (kookana et al., 2011). consequently, this compound has been discovered in a variety of organisms, including fish, algae, plants, and humans at high consentrations (oliveira et al., 2009). additionally, it has been discovered in natural waters and wastewater treatment plant effluents (fu et al., 2016). triclosan, for instance, was found in wastewater treatment plant effluent at concentrations ranging from 1-10 µg/l (adolfsson-erici et al., 2002; ying et al., 2007). during wastewater treatment operations, triclosan is diffused into particulate and dissolved organic materials. biosolid analytes contained triclosan values ranging from 0.33 to 130 mg/kg (heidler and halden, 2007). the concentration of triclosan in soil enriched with solid organic matter is calculated at 4.5 mg/kg arid mass (fuchsman et al., 2010). antimihttps://doi.org/10.26554/ijems.2023.7.2.56-61 sipahutar indonesian journal of environmental management and sustainability, 7 (2023) 56-61 crobial compounds may be introduced into agricultural soil as a result of biosolids land application. the existence of significant amounts of triclosan in soils may result in the gradual accumulation and hazardous stages of triclosan in the surface-dwelling environment (fu et al., 2016). rare studies have revealed the toxicity of triclosan with numerous bioassays. the goal of the current study is to clarify the biological danger of triclosan on plant tissue and microorganisms in order to address this issue. escherichia coli (e. coli) was used for the assessment of the antimicrobial activity of triclosan. vigna radiata (mung bean) and crotalaria juncea (sunn hemp) seeds were used in phytotoxicity evaluation to determine triclosan uptake because legumes are commonly consumed and are known to be sensitive to contaminants. allium cepa was used for the cytogenotoxicity test. these findings are anticipated to provide additional information on the environmental fatality and latent biological harm of triclosan. 2. experimental section 2.1 chemicals and reagents triclosan was supplied by the tokyo chemical industry, japan. the purity of triclosan was greater than 96%. acetone was purchased from j.t. baker (manufactured in the usa). all other compounds were of analytical grade. 2.2 microbial toxicity test effect of triclosan on microorganism augmentation was determined by injecting a strain of e. coli into a triclosanconceiving mueller-hinton broth and contrasting it to a similar bacterium raised in a triclosan-unrestricted medium (wen et al., 2015). briefly, a series of tubes containing 3 ml of untainted mueller-hinton broth with or without the supplement of triclosan were prepared (0–150 µm, ph 7.0). each spout was shot with 1 ml of an e. coli cell suspension at a concentration of 2.4×109 cfu/ml (cfu, colony forming units) and incubated at a temperature of 35±1°c for 24 hours (griffin et al., 2000; kowalska-krochmal and dudek-wicher, 2021). 2.3 phytotoxicity test considering how sensitive plants are to toxins, the initial toxicity experiment’s goal was to ascertain whether legume seedlings were affected by root growth suppression. germination percentage, seedling survival, and sprouting length are measures of plant growth that have been used to gauge how plants react to different contaminants. vigna radiata and crotalaria juncea were selected for this research because legumes are commonly consumed. considering the plants’ high sensitivity to a toxic substance (triclosan), the goal of such a toxicity experiment was to determine the inhibition of root growth in vigna radiata and crotalaria juncea seeds. triclosan with 40 and 80 µm concentrations was extracted with acetone, dried, dispersed to the preliminary quantity in water that had been distilled, and tested for noxiousness. the phytotoxicity of treated samples was evaluated using a bioassay for seed germination (raj et al., 2014). five seeds of each vigna radiata and crotalaria juncea were surface-sterilized (tadashi et al., 2011). in each petri plate, five seeds of either the test solution (triclosan) or deionized water (a control) were deposited on filter paper. the plates were incubated for 72 hours in a growth chamber with 80% humidity, a cycle of 14 hours of light and 10 hours of darkness, and a constant temperature of 25°c. at the end of the exposure period, the level of toxicity was evaluated in relation to seed germination inhibition and sprouting length compared with the control; this reflected non-harmfulness to the seeds and the maximal sprout length. 2.4 cytogenotoxicity test assessment of cytogenotoxicity was performed using allium cepa. triclosan at 40 and 80 µm concentrations was extracted with acetone, dried, liquified to an early volume in distilled water, and tested for toxicity. as demonstrated by prasad et al., cytogenotoxicity was tested on meristematic root tip cells of a healthy allium cepa (prasad et al., 2013). shortly, healthful allium cepa bulbs were preserved in pure water for 72 hours in a dark place after the outer peel and dehydrated roots were deleted. every day, the distilled water was changed. after that, the best fresh root tips (±2.5 cm) were chosen for the treatment. for 4 hours, the root tips were subjected to two distinctive concentrations of triclosan (40 and 80 µm). as a control, distilled water was applied to the root tips. following that, root tips were incubated in glacial acetic acid and 95% ethanol for 90 minutes, steeped in 1 n hcl for 10 minutes, and rinsed in decontaminated water. on a microscope slide, the root tips were stained with 1% aceto-orcein and compressed in 45% acetic acid. bright field microscopy at 1000× magnification was used to look for chromosomal aberrations and cell dissection in the stained root tips. the mitotic index was determined as the percentage of split cells per total number of cells assessed (1250). 2.5 statistical analysis the result was analyzed by means of a one-way anova with dunnett’s multiple comparisons test. all tests were carried out in triplicate. the mean sd (standard deviation) of the results was displayed. 3. results and discussion 3.1 antibacterial activity of triclosan because of its concise phase and wide application in biotechnology and microbiology, the e. coli strain is a supreme commencing object for assessing triclosan toxicity. the toxicity of triclosan to e. coli was determined by calculating the cfu of e. coli in mueller-hinton agar. this study revealed that at low triclosan concentrations (5-7.5 µm), the impact of triclosan on bacterial growth was low. nevertheless, as © 2023 the authors. page 57 of 61 sipahutar indonesian journal of environmental management and sustainability, 7 (2023) 56-61 triclosan concentration increased (60-150 µm), all of the triclosan tested became extremely dangerous to the test bacterium, as demonstrated by the decreasing number of cfu of e. coli. these findings suggest that triclosan may be less toxic to bacteria at low concentrations, but triclosan has much stronger anti-bacterial activity at higher concentrations. the higher the triclosan concentrations, the fewer e. coli cfu were present (figure 1). figure 1. the cfu of e. coli following exposure to various triclosan doses butler et al. discovered that triclosan was toxic to microbial communities in three soils tested (butler et al., 2012). despite being consistent with their results, these results could not be matched to theirs due to the several altered experimental conditions used (e.g., triclosan concentrations). in fact, it has been demonstrated that the antibacterial compound triclosan prevents the growth of a diverse group of microorganisms, such as yeasts, algae, and bacteria. it has a long history of use in antiseptics and disinfectants (chen et al., 2023). although the exact mechanism is still unknown, it is thought to be connected to their contact with (or possibly infiltration into) the membrane composition of the bacteria. their integrity of the membrane is compromised by this interaction or penetration, which leads to their amassing on the cell membrane and aggregation (petkovic et al., 2010). 3.2 phytotoxicity of triclosan triclosan discharge into the soil not only poses significant concerns for the environment and human health, but it also directly affects soil fertility. as a result, triclosan’s phytotoxicity must be evaluated. the phytotoxic activity of triclosan was determined by incubating legume seeds on wet tissue in a petri dish. phytotoxic activity was detected in seed germinations for 72 hours. this research compared the sprouting length of two legumes, vigna radiata and crotalaria juncea, that had and had not been exposed to triclosan. figure 2 and figure 3 show how triclosan affects the sprouting length of vigna radiata and crotalaria juncea at concenfigure 2. an evaluation of the phytotoxicity of triclosan at concentrations of 0 (as control), 40, and 80 µm using vigna radiata and crotalaria juncea expressed as sprouting length figure 3. toxicity assessment of triclosan at the concentrations of 0, 40, and 80 µm on the sprouting length of vigna radiata (a) and crotalaria juncea (b) trations of 0, 40, and 80 µm. according to our data, the phytotoxic effect of triclosan was the same for both legumes. when seeds were subjected to increasing concentrations of triclosan, sprouting length decreased in comparison to the control. the sprouting length of both vigna radiata and crotalaria juncea decreased by 45-50% and 70-72% when seeds were exposed to triclosan at concentrations of 40 and 80 µm respectively, compared to the control. this result was strengthened by the study of karnjanapiboonwong et al., which discovered that bean plants (phaseolus vulgaris) cultivated in sand and dirt were poisonous to triclosan (pullagurala et al., 2018). our results are compatible with theirs but cannot be equaled because of the varied experimental setups used. since this study focused on the in vitro interactive effect of an increased emission rate of one compound (triclosan), more research on the effects of triclosan in vivo under real environmental conditions is required. 3.3 cytogenotoxicity in nature, triclosan and its by products are known to be cytotoxic or carcinogenic (li, 2021). based on the results of © 2023 the authors. page 58 of 61 sipahutar indonesian journal of environmental management and sustainability, 7 (2023) 56-61 table 1. chromosomal aberration and mitotic index examined in root tip cells of allium cepa treated with triclosan and distilled water concentration of the compound (µm) no. of dividing cells mitotic index (mi) % aberration index (ai)% chromosomal aberrations ml ma al cb distilled water (control) 191a 18.2±0.93a 0.1±0.03c 0 0.63±0.31 0 0 triclosan 40 108d 10.4±0.23d 1.2±0.22a 3.03±0.86 2.27±0.34 4.35±0.72 2.61±0.41 80 93d 8.8±0.36d 1.4±0.11a 0 2.99±0.37 2.12±0.34 4.94±0.23 chromosomal aberration per 1050 cells; mitotic index (mi) % = (number of dividing cells/total number of cells observed)×100. ml: metaphase lagging chromosome; ma: metaphase aberration; al: anaphase lagging chromosome; cb: chromosome breaks. each value represents the mean ± sd of three replicates per treatment. in the same column according to dunnett’s multiple comparison test significant differences at p < 0.05 levels over control are indicated by different letters. this study, triclosan, as an active antimicrobial agent, demonstrated momentous cytotoxicity on allium cepa used in a genotoxicity test. allium cepa assessment is a straightforward, efficient, dependable, and widely recognized method for observing the effects of exposure to probable carcinogens or mutagens on systems. table 1 shows the mitotic indexes and chromosomal aberrations in, meristematic cells of allium cepa spoiled with triclosan. at 40 µm triclosan concentration, the maximum aberration index (1.2%) was observed, with the lowest percent (10.4%) of mitotic index, and at 80 µm triclosan concentration, the maximum aberration index (1.4%) was observed, with the lowest percent (8.8%) of mitotic index. figure 4. study of cytogenotoxicity in allium cepa meristematic cells. the following conditions were used: a control using distilled water (a); triclosan treatments at 40 (b) and 80 µm (c) in contrast to non-toxic distilled water (the control), which showed a greater mitotic index percentage, cells treated with increasing concentrations of triclosan showed a drop in the mitotic index percentage, demonstrating triclosan’s toxicity. as concentration rose, the rate of aberration increased. to analyze chromosomal abnormalities, several types of genotoxic damage were investigated, including metaphase lagging chromosomes, metaphase aberrations, anaphase lagging chromosomes, and chromosome breakage. figure 4(a) shows healthy cell division as seen through microscopic examination of the chromosomes of the control (distilled water) allium cepa meristematic cells. in both concentrations of 40 and 80 µm, irregular phases were discovered to be the most common anomalies and chromosomal damage (figures 4(b) and 4(c)). cells treated with triclosan showed chromosome breakage, abnormal cells, and death cells. the most frequent anomalies were found to be aberrant metaphase, multipolar anaphase, and irregular prophase at concentrations of 40 µm. chromosome bridges and death were thus observed at 80 µm as a result of insufficient chromosome replication. similar abnormalities were seen in root cells treated with triclocarban, another antiseptic (sipahutar and vangnai, 2017). in cells treated with triclocarban, spindle abnormalities, such as multipolarity, are frequently observed. in cells that have been exposed to the antiseptic chemicals, binucleated cells are present that were most likely produced by multipolar spindles. 4. conclusions we investigated the effects of triclosan on a range of living things, including the bacteria e. coli, the legume plants vigna radiata and crotalaria juncea, and the genetic material cells found in the allium cepa root. according to the latest research, allium cepa roots, crotalaria juncea, and vigna radiata seeds, as well as cfu of e. coli, were reliable indicators of the acute toxicity of triclosan. significant antibacterial action against e. coli was present in triclosan. the phytotoxicity of triclosan in bean plants was further demonstrated by the notable reductions in the length of their sprouts. allium cepa root cells used in a cytogenotoxic test showed a wide range of chromosomal aberrations, suggesting that triclosan affects the plant’s normal growth. additional indicators of cytogenotoxic effects in the root meristematic of allium cepa included a reduced mitotic index (mi), an increased aberration index (ai), other chromosomal abnormalities, and micronuclei. the evaluation of microbiological toxicity, phytotoxicity, and cytogenotoxicity points to the possibility of triclosan having a negative effect on the biota. © 2023 the authors. page 59 of 61 sipahutar indonesian journal of environmental management and sustainability, 7 (2023) 56-61 5. acknowledgement the author thanks yapenti-balikpapan university (uniba) for the financial support and prof. alisa vangnai of the department of biochemistry, chulalongkorn university, bangkok, thailand, for supervising this work. references adolfsson-erici, m., m. pettersson, j. parkkonen, and j. sturve (2002). triclosan, a commonly used bactericide found in human milk and in the aquatic environment in sweden. chemosphere, 46(9-10); 1485–1489 baalbaki, z. 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300–305 © 2023 the authors. page 61 of 61 introduction experimental section chemicals and reagents microbial toxicity test phytotoxicity test cytogenotoxicity test statistical analysis results and discussion antibacterial activity of triclosan phytotoxicity of triclosan cytogenotoxicity conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper developing an environmental management accounting framework for the waste management sustainability of municipalities in south africa thomas nyahuna1*, mishelle doorasamy2 1school of accounting, economics and finance, university of kwazulu natal, kwazaulu natal, 4339, south africa 2department of financial accounting, school of accounting, economics, and finance, university of kwazulu natal, kwazulu natal, 4339, south africa *corresponding author e-mail: thomasnyahuna@yahoo.com abstract the aim of the study is to identify environmental management accounting (ema) practices currently used by the municipalities in south africa in enhancing municipal solid waste management. to accomplish the aim of the study, 32 in-depth interviews were conducted with accountants, environmental managers and municipals managers on 10 municipalities in south africa. thematic analysis’s was used to analyse the data and unearthed that environmental management system, waste management system, environmental reporting, environmental training and research and development are currently used as ema practices to boost municipal solid waste management. to align these practices with the accounting system in municipalities, an ema model was proposed that can make available monetary and non-monetary waste-related environmental information. keywords environmental management accounting, municipalities, framework, practices, south africa, environmental reporting received: 1 december 2021, accepted: 1 march 2022 https://doi.org/10.26554/ijems.2022.6.2.35-41 1. introduction municipal solid waste generation has become a key source of environmental challenges. panya et al. (2018) posit that this is because the environmental externalities emerging from improper municipal solid waste management were for long time ignored. in most developing countries such as south africa this has led to enormous pressure on waste disposal capabilities by municipalities. in developing countries, solid waste management remains a central role of the municipalities. municipal solid waste management (mswm) advances issues such as “generation, collection, transport, treatment, and disposal of waste” (bartolacci et al., 2018). when not properly treated, waste can contribute to negative impacts on public health and environmental degradation. solid wastes are a major source of greenhouse gas emissions. bharadwaj et al. (2020) point out that this classifies the municipalities, through poor waste management, as chief contributors to climate change. according to scholarly estimates, waste disposal is responsible for about 5% of the global ghg emissions. as climate change is world wide scourge, it also has been disturbing south africa in form of inconsistency in rainfall and life-threatening weather conditions. the improper management of mswm contributes 3% of the south africa’s ghg emissions (adeleke et al., 2021). department of environmental management report, there has been a 31% increase in waste generation in south africa for the past 5 years. this effectively calls for proper systems and solutions to be in place to curtail the effect of the poor mswm in order to achieve sustainability. even though, there are policies and regulations in place to lessen poor mswm, it is critical to investigate the exact measures of environmental management practices municipalities are employing to minimise impacts from solid waste management. this helps to recommend practices that need special attention based on contemporary literature. qian et al. (2018) contend that environmental management practices adopted by municipalities to improve solid waste management remain unknown. this is further supported by adeleke et al. (2021) that environmental measures to enhance sustainability from the perspective of the mswm needs scholarly attention to be established. this provides a research area that needs to be explored. hence, this study aims to identify environmental management practices used by south african municipalities to improve solid waste management. by identifying the environmental management practices mostly used by the local municipalities, it provides a solid ground to develop and propose an environmental management accounting (ema) framework that specifically enhances waste management sustainability. this is because https://doi.org/10.26554/ijems.2022.6.2.35-41 nyahuna and doorasamy indonesian journal of environmental management and sustainability, 6 (2022) 35-41 previous studies have mostly provided engineering and technical solutions to the extant challenges from the mswm. for that reason, qian et al. (2018) affirm that ema has been neglected and is still unknown in the municipalities. in this regard, this study proposes ema as a pathway to poor mswm in south africa. rikhardsson (2005) define ema as “the generation, analysis and use of financial and non-financial information in order to optimise corporate environmental and economic performance and to achieve sustainable businesses”. absence of waste related data has been cited as key factor majorly contributing to poor mswm (qian et al., 2018; adeleke et al., 2021; dlamini et al., 2019). in this case, ema will ensure that both financial and non-financial environmental waste-related information is provided for management decision making. by presently using the traditional management accounting system, municipalities are not able to collect the financial and non-financial information waste-related data. this implies that management are not making sound and evidence-based decisions as some critical environmental information will be missing. this brings in and makes ema relevant to the municipalities. moreover, the few ema studies in municipalities have been conducted in developing countries such as australia and canada (qian et al., 2018; ball and craig, 2010; qian et al., 2011). this means that globally ema in the municipalities has not been sufficiently subjected to scientific studies. unfortunately, in direct contrast to global needs (burritt et al., 2019), a large number of the prior studies were carried out in developed countries, the results of which may offer some valuable insights but cannot be strictly extrapolated to emerging markets such as south africa. hence, this study becomes crucially important to close this gap from an emerging markets perspective. to fill this gap, this study focuses on identifying ema practices in municipalities in south africa; an emerging market economy and thereof propose an ema framework to enhance sustainability of the municipalities in south africa. setthasakko (2010) and chathurangani and madhusanka (2019) argue that without ema frameworks organizations are unlikely to be able to adopt ema tools. hence, this study proposes a municipal sector specific ema framework. table 1. number of interviewees job title number of respondents accountants/cfos 13 environmental managers/ 11 officers municipal managers 8 total 32 cfo = chief financial officer 2. experimental section 2.1 materials and method to identify the environmental management accounting practices currently implemented by municipalities to improve solid waste management, 32 in-depth interviews consisting of municipalities’ accountants/cfos, environmental managers and municipal managers were conducted within a total of 10 municipalities across south africa as displayed on table 1. 32 interviews involving 13 accountants /cfo, 11 environmental managers or officers and 8 municipal managers were undertaken. purposive sampling was done targeting municipalities in charge of urban towns because this is where solid waste is mostly encountered. also, certain employees that were perceived to have adequate knowledge were purposively selected to answer the research questions. in-depth interviews were done to collect data from respondents. 2.2 data analysis the transcripts of each interview were transcribed based on braun and clarke (2006) thematic analysis procedures. theme or pattern identification is central to data conceptualisation. the following elaborates on themes that emerged from data analysis. the quest for a sustainable health life is perpetually putting municipalities under severe pressure from stakeholders to reduce negative impacts from poor mswm such as ghg emissions, related diseases and blocked drainage. to achieve this, it was critical to identify ema practices currently adopted by the municipalities to overcome negative impacts from solid waste management. this was important as it facilitated recommendations on the current practices on what can be improved to have better mswm. in the same vein, an ema model was proposed to act a decision making tool on waste-related issues. 32 interviews from cfos/accountants, environmental managers and municipal managers indicated that municipalities in south africa are mostly using five ema practices to address mswm. the five ema practices are ems, waste management systems, environmental reporting, environmental training and research and development. these results show that municipalities in south africa have a commitment to improve environmental and social impacts emanating from mswm. unfortunately, the municipalities are using traditional management accounting system to provide environmental information for management decision making. this calls for integration with ema systems to have one system. the absence of ema systems within municipalities in south africa partly contributes to the poor mswm as current ema practices applied by the municipalities need a better accounting system in order for their effectiveness to be greatly recognized. © 2022 the authors. page 36 of 41 nyahuna and doorasamy indonesian journal of environmental management and sustainability, 6 (2022) 35-41 table 2. ema practices used by municipalities ema practices applied number of municipalities applying by municipalities identified ema practice environmental management system 10 waste management system 8 environmental reporting 7 environmental training 6 environmental research 5and development 3. results and discussion a closer analysis of the interviews transcripts reflect the following environmental management accounting practices as being mostly applied by the municipalities in south africa. 3.1 environmental management systems (ems) table 2 shows that the most widely used solid waste management improvement practice in the local municipalities is the ems. all the 10 sampled or 100% of the municipalities confirm using ems as a tool to improve solid waste management. khanna and anton (2002) defined ems as “collection of internal efforts at formally articulating environmental goals, making choices that integrate the environment into production decisions, identifying opportunities for pollution (waste) reduction and implementing plans to make continuous improvements in production methods and environmental performance”. khanna and anton (2002) further reveal that ems includes numerous environmental practices. deegan (2003) adds that ems usually fail to avail accounting information to help managers in different decisions, but it is submitted that environmental accounting is a key component of a broad ems since it “supports the compilation and analysis of relevant environmental information that is required to make decisions based on environmental impact added data” (gadenne and zaman, 2002). by adopting ems, municipalities show a commitment to protect the environment. for instance, phan et al. (2017) emphasise that by using ems, environmental trainings are regularly conducted which provides employees with skills and knowledge to gather and process ema information. this simplifies the better adoption of both monetary and non-monetary ema information. 3.2 waste management systems a waste management system can be defined as “management of all responsibilities, practices, procedures, processes and resources for establishing a system that manages waste and complies with environmental regulations” (panya et al., 2018). municipal waste management system consists of treating solid wastes. so, waste management systems expect to minimize negative impacts on public health and the environment. currently, 8 of the 10 sampled municipalities in south africa prefer using waste management systems as a pathway to mswm. in this regard, municipalities ensure that collecting, sorting, treating and recycling of wastes are properly done. this is inconsistent with prior studies. for instance, panya et al. (2018) note that waste management system elevates swm in waste management companies in india. the authors believe that waste management systems remain the bedrock of swm. however, some studies contradict this finding. in one study, teles et al. (2015) found that waste management systems are not directly related to environmental performance. in addition, voinea et al. (2020) affirm that waste management systems are less effective on enhancing sustainability. 3.3 environmental reporting literature is awash with studies (de beer and friend, 2006; gale, 2006; burritt et al., 2019; chathurangani and madhusanka, 2019) acknowledging that environmental reporting is a key practice of ema. environmental reporting in form of wastes collected within certain periods was also identified as a measure to improve mswm. 70% or 7 of the municipalities resort to environmental reporting as part of a solution to environmental problems from mswm. in south africa, the emergence of king code iii and iv transformed the governance structure. the codes and the national treasury mandated that municipalities extensively report on their environmental and sustainability issues. the environmental reporting in municipalities help communicate municipal performance on swm to both internal and external stakeholders. in this way, stakeholders put considerable pressure on municipalities to actively improve swm based on reported figures in annual reports. environmental reporting remains the bedrock of ema. by providing monetary and non-monetary environmental information, it is perceived that that improves management decision making in areas such solid waste management. however, the current reporting in all municipalities is done from the traditional management accounting system. ifac (2005) and burritt et al. (2019) note that this system cannot accurately administer ema information. this suggests that municipalities in south africa need to consider and adopt ema as part of the mainstream accounting systems in or© 2022 the authors. page 37 of 41 nyahuna and doorasamy indonesian journal of environmental management and sustainability, 6 (2022) 35-41 der to enjoy benefits of using monetary and non-monetary environmental information. 3.4 environmental training municipalities show that staff environmental training is quite common in addressing waste management. this is in sync with studies that training of staff on environmental matters augments environmental and financial performance. recent studies by fuadah et al. (2021) and dlamini et al. (2019) recommend that the corporate sector proactively focus on shifting the mindset of employees as game changers towards environmental issues through training on environmental matters. in contrast, bananuka et al. (2021) demonstrate that employee training on environmental issues has a negative impact on environmental performance. based on the findings, this means environmental staff training does not increase environmental performance. 3.5 environmental research and development respondents from five municipalities confirm that environmental research is being conducted to find better ways of improving mswm. in other words, almost 50% of the sampled municipalities in south africa are employing environmental research as an environmental management tool specifically to improve mswm. united nations (2001) describes environmental research and development as a process to establish better ways of resolving environmental problems. in this case, in municipalities, environmental research on mswm concentrates on the transformation on going in the natural and human environments emanating from human actions with the key aim to grasp these changes or to find way out or solutions. in similar settings, scholars such as magara et al. (2015) noted the importance of environmental research as a way of addressing environmental concerns. furthermore, south africa’s government in a bid to reduce climate change impact sponsored and strongly encouraged environmental research. as a result, this has seen a large number of municipalities adopting environmental research as a sustainability tool. conversely, empirical studies of kurapatskie (2012) found out that environmental research was not statistically significant to enhance environmental issues. based on literature review and findings of the ema practices currently used in south african municipalities to improve mswm, an ema framework can be proposed to enhance waste management sustainability. this framework will assist municipalities to collect monetary and non-monetary waste-related environmental information for management decisions. scholars (de beer and friend, 2006; ferreira et al., 2010; gibassier and alcouffe, 2018; gunarathne and lee, 2015; qian et al., 2018) concede that getting environmental information improves corporate environmental and financial performance. 3.6 proposed ema framework to enhance waste management sustainability stage 1, in figure 1, the primary step would be the collection of data. this can be in form of monetary and non-monetary environmental data. this helps to ensure that waste levies are accurately charged on to residents because all the required waste-related information will be readily available (qian et al., 2018). ball and craig (2010) argues that without accurate waste-related data municipalities are set to face acute financial challenges in the long term originating from inaccurate waste levies and other waste management costs recouped from residents. therefore, monetary and non-monetary data help improve financial sustainability organizations like municipalities. literature shows that the collection of the data is, in most cases, hindered by a communication gap between the accounting department and other environmental management departments (tsui, 2014). the proposed ema framework narrows the gap by linking the collection of waste-related data from the environmental management and accounting departments. in stage 2, once all the relevant data has been collected, as reflected on figure 1, it is important that the traditional management accounting system is merged with ema system. this is to ensure that the collected waste-related environmental data can be processed to produce specific environmental information such as environmental costs associated with swm that cannot be generated from the traditional management accounting system. at this stage, externalities aligned to a cost centre responsible for environmental costs creation can be captured into the ema system (ifac, 2005). also, the integration of traditional management accounting system and ema systems enable municipalities to establish the size of their waste management impacts such as pollution, emissions and cost of solid wastes chemicals in monetary and physical terms. the quantification of ema impacts in stage 3 is vital in reducing social, environmental and financial impacts as environmental impacts are the crucial components to be incorporated and shown in an organization’s accounting system as shown in figure 1. gray (2010) argues that by addressing environmental and financial impacts, social impacts would also have been resolved. hence, the model framework focuses on environmental and financial impacts of swm. after being able to quantify environmental impacts in monetary and non-monetary terms, municipalities will be expected to provide a detailed report generated from ema systems to both interested internal and external stakeholders. this is done in stage 4. this report details waste-related environmental issues such as volumes of wastes collected at a certain period or monetary value of chemicals used to treat wastes during a certain time frame. this provides stakeholders an opportunity to hold municipalities to account for their actions on environmental impacts stemming from poor mswm (qian et al., 2018). also, this assists to exert pres© 2022 the authors. page 38 of 41 nyahuna and doorasamy indonesian journal of environmental management and sustainability, 6 (2022) 35-41 figure 1. proposed ema framework sure on municipalities to extensively adopt measures such as ema tools as an answer to calls to reduce waste-related environmental impacts. stage 5, as shown in figure 1, with all accurate and adequate environmental waste-related data at the disposal of stakeholders, a decision need to be taken on the course of action required should there be material negative environmental impacts emanating from swm. this is an jallstakeholders’ involvement. the idea is to explore any improvement opportunities on swm from various stakeholders. it is at this time that it can be identified on what is hindering the municipalities from attaining proper mswm. in this regard, action can then be taken to root out the major obstacles standing in the way of achieving better mswm. in this way, enhanced swm would be closer to achievement. to remain effective on mswm, municipalities need to constantly maintain and repeat this cycle of activities. 4. conclusions ema practices currently used by 10 municipalities across south africa to improve municipal solid waste management were identified. these practices were identified based on 32 in-depth interviews with municipalities’ accountants/cfos, environmental managers and municipal managers. as such, the findings have to be analyzed with caution as applicability cannot be guaranteed in other municipalities. the study’s empirical results reveal that environmental management system is the mostly applied ema practice by the 10 municipalities in south africa to improve municipal solid waste management. furthermore, the other ema practice used by these municipalities to improve solid waste management in ascending order are waste management system, environmental reporting, environmental training and, finally, environmental research and development. by identifying these ema practices used by municipalities in south africa the study has also contributed to present literature. qian et al. (2018) clearly state that ema practices used by municipalities are unknown and this has never been undertaken in the current literature. the goal of this research study is for municipalities to improve current ema practices applied to enhance mswm through adoption and implementation of ema systems. this study is without limitations. the sample size was small hence future studies can enlarge sample size and number of respondents. also, future studies can focus on how the various stages of the proposed ema framework can be implemented within municipalities. 5. acknowledgement i gratefully appreciate the time and effort of the respondents to engage us despite their tight schedules. © 2022 the authors. page 39 of 41 nyahuna and doorasamy indonesian journal of environmental management and sustainability, 6 (2022) 35-41 references adeleke, o., s. a. akinlabi, t. c. jen, and i. dunmade (2021). sustainable utilization of energy from waste: a review of potentials and challenges of waste to energy in south africa. international journal of green energy, 18(14); 1550–1564 ball, a. and r. craig (2010). using neo institutionalism to advance social and environmental accounting. critical perspectives on accounting, 21(4); 283–293 bananuka, j., l. bakalikwira, p. nuwagaba, and z. tumwebaze (2021). institutional pressures, environmental management practices, firm characteristics and environmental performance. accounting research journal, 9; 1–29 bartolacci, f., a. paolini, a. g. quaranta, and m. soverchia (2018). assessing factors that influence waste management financial sustainability. waste management, 79; 571–579 bharadwaj, b., r. k. rai, and m. nepal (2020). sustainable financing for municipal solid waste management in nepal. plos one, 15(8); e0231933 braun, v. and v. clarke (2006). using thematic analysis in psychology. qualitative research in psychology, 3(2); 77–101 burritt, r. l., c. herzig, s. schaltegger, and t. viere (2019). diffusion of environmental management accounting for cleaner production: evidence from some case studies. journal of cleaner production, 224; 479–491 chathurangani, h. and k. madhusanka (2019). environmental management accounting (ema) adoption level among listed manufacturing companies in sri lanka: institutional theory perspective. research in social sciences, 2(1); 1–12 de beer, p. and f. friend (2006). environmental accounting: a management tool for enhancing corporate environmental and economic performance. ecological economics, 58(3); 548–560 deegan, c. m. (2003). environmental management accounting: an introduction and case studies for australia. australia: institute of chartered accountants in australia dlamini, s., m. d. simatele, and n. serge kubanza (2019). municipal solid waste management in south africa: from waste to energy recovery through waste to energy technologies in johannesburg. local environment, 24(3); 249–257 ferreira, a., c. moulang, and b. hendro (2010). environmental management accounting and innovation: an exploratory analysis. accounting, auditing & accountability journal, 23(7); 92–109 fuadah, l. l., u. kalsum, and a. arisman (2021). determinants factor influence environmental management accounting and corporate environmental performance: evidence in indonesia. journal of southwest jiaotong university, 56(3); 582–602 gadenne, d. and m. zaman (2002). strategic environmental management accounting: an exploratory study of current corporate practice and strategic intent. journal of environmental assessment policy and management, 4(2); 123–150 gale, r. 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(2005). implementing environmental © 2022 the authors. page 40 of 41 nyahuna and doorasamy indonesian journal of environmental management and sustainability, 6 (2022) 35-41 management accounting: status and challenges, volume 18. springer setthasakko, w. (2010). barriers to the development of environmental management accounting: an exploratory study of pulp and paper companies in thailand. euromed journal of business, 5(3); 315–331 teles, c. d., j. l. d. ribeiro, m. a. c. tinoco, and c. s. ten caten (2015). characterization of the adoption of environmental management practices in large brazilian companies. journal of cleaner production, 86; 256–264 tsui, c. s. (2014). a literature review on environmental management accounting (ema) adoption. web journal of chinese management review, 17(3); 1–19 voinea, c. l., b. j. hoogenberg, c. fratostiteanu, and h. bin azam hashmi (2020). the relation between environmental management systems and environmental and financial performance in emerging economies. sustainability, 12(13); 1–21 © 2022 the authors. page 41 of 41 introduction experimental section materials and method data analysis results and discussion environmental management systems (ems) waste management systems environmental reporting environmental training environmental research and development proposed ema framework to enhance waste management sustainability conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper current management of pesticides wastes in some cultivating models in vietnamese mekong delta tran thi kim hong1, nguyen thanh giao1* 1college of environment and natural resources, can tho university, can tho city 900000, vietnam *corresponding author e-mail: ntgiao@ctu.edu.vn abstract the study was carried out to evaluate the current status of use and management of waste from pesticides on some farming models in the mekong delta through interviews with 140 households cultivating triple-rice, durian ri6 and e-dor longan. the results of the study showed that 130 types of pesticides and 99 active ingredients were used on three farming models. the study also discovered that five banned active ingredients are still used in the triple-rice practice and four banned substances in the durian ri6 cultivation. the proportions of toxic groups (according to who’s classification) at levels ii, iii, iv were 33.3%, 29.3% and 37.4%, respectively. the triple-rice crop model used the most pesticides, but the frequency of spraying was only in the range of 6.48±1.72 to 7.33±1.82 times/crop. meanwhile, the durian ri6 model, although using fewer pesticides, the frequency of spraying was very high (about 61.8±9.1 times/crop), 9 times higher than a rice crop. the cultivation of e-dor longan uses the least amount of pesticides as well as a very low frequency of spraying. the methods of handling pesticidal wastes are mainly burning, burying and these practices are not meeting the requirements for protecting health and the environment. the study provides important information for decision-making to choose a farming model and the accompanying environmental protection solutions to minimize the adverse effects of the use of pesticides. keywords pesticides, triple-rice, e-dor longan, durian ri6, mekong delta received: 14 june 2022, accepted: 4 september 2022 https://doi.org/10.26554/ijems.2022.6.3.98-103 1. introduction the mekong delta is known as the largest producer and exporter of food and fruit trees in vietnam. in which, the rice cultivation area accounts for 54.5% of the country’s cultivated area and accounts for more than 90% of the exported rice. along with that, the rice industry in the mekong delta has always improved and bred many new rice varieties with more advantages such as increased yield, increased quality of commercial rice grains and increased adaptability for rice in the future of climate change conditions. therefore, rice production is the main livelihood of many households today. however, the current rice farming model does not guarantee economic benefits for farmers’ livelihoods because many factors such as dikes reduce the amount of silt in the fields, land degradation due to continuous cultivation with high density and heavy use of fertilizers (duyen and tri, 2015). according to the report of an giang department of agriculture and rural development in the period 2016-2018, production costs for plant protection accounted for 21.2% and chemical fertilizers were 27.7%, accounting for 48.9% of total costs in rice cultivating. nam et al. (2021) reported that the profit of the three-crop rice model in tri ton, an giang in the pre-flood season is only 11.4 million vnd/ha/crop and 15.8 million vnd/ha/crop after the flood season. the three-rice crop model in thanh phu, ben tre only got 9.04 million vnd/ha/crop and two-rice crop also reached 13.03 million vnd/ha/crop (linh et al., 2021a). thereby, as can be seen that the current traditional rice farming model has not brought high efficiency. the models of fruit cultivation with new plant varieties that are said to be highly effective are now being converted by many households from rice or other crops with low economic efficiency to mass planting such as durian ri6, green grapefruit, king orange, e-dor longan. an giang province alone has converted more than 10,000 hectares of inefficient rice farming land to fruit trees (ministry of agriculture and rural development , 2022). these models hold many positive hopes to improve the economy as well as the lives of people in the mekong delta. however, with the current production habits associated with the use of pesticides, the current value of agricultural products is not high. along https://doi.org/10.26554/ijems.2022.6.3.98-103 hong et. al. indonesian journal of environmental management and sustainability, 6 (2022) 98-103 with the selling price of the product, the cost of pesticides always affects the profit of farmers in agricultural production. accompanying that is the unreasonable use of pesticides, especially intensive use, exceeding the recommended level, spraying with high frequency, using pesticides on the list of not allowed and untreated excess amount of pesticides, waste from pesticides, especially the management of pesticide packaging after use (toan, 2013; nhan et al., 2015). these things have caused the environment in the area to become increasingly polluted. the use of pesticides and chemical fertilizers in the mekong delta has been increasing in recent years. the report on the current state of the environment in 2018 showed that the issue of agricultural wastewater is currently a topic worthy of attention in the mekong delta, of which it is estimated that every year there are about 70,000 kg of fertilizer, more than 40,000l pesticides and about 70 thousand kg of untreated chemical packaging enter the environment, especially groundwater and surface water, increasing pollution levels (ministry of natural resources environment, 2018). this study was conducted to investigate the current status of pesticide use and waste management in some farming models in the mekong delta, vietnam. the results provide important information on environmental aspects of agricultural production restructuring in the mekong delta. 2. materials and methods 2.1 data collection the study collects data through the process of field survey and direct interview with 140 households cultivating triplerice (30 households), durian ri6 (70 households) and e-dor longan (40 households) in a rural areas of can tho and vinh long province in the mekong delta, vietnam (figure 1). the collected data includes information about types of pesticides, frequency of use, level of knowledge about pesticides, methods of handling pesticidal wastes after use. the active ingredients of pesticides are used to classify the degree of toxicity according to who’s classification. in this study, the active ingredients of pesticides were searched on the software of the department of plant protection in vietnam and the website of the united states environmental protection agency based on the names of the pesticides examined. potential impacts of pesticides on environment and human health are evaluated using toxicity data reported by the pesticide’s producers and environmental toxicity database. 2.2 classification of pesticide toxicity according to the world health organization (who), the toxicity of pesticides is expressed in terms of ld50 (lethal dose 50) which is the lethal dose for 50% of the experimental animals, expressed in milligrams (mg) of the active ingredient of the drug/kg of experimental body weight (on mice). the lower the ld50 value of a drug, the higher the acute toxicity to warm-blooded animals. this means that the drug is more dangerous and potentially deadly to humans and animals. this classification helps to identify and distinguish toxicity among pesticides on products consumed in vietnam (table 1). 3. results and discussion 3.1 current use of pesticides in some agricultural cultivating models the survey results in figure 2 showed that triple-rice cultivation have been detected about 65 pesticides with 54 active ingredients, including pesticides, fungicides, herbicides, raticides and growth stimulants. the model of durian ri6 were found 59 pesticides used with 41 active ingredients. meanwhile, the e-dor longan model has only detected six pesticides with 4 active ingredients which is much lower than the other two cultivating models. the cultivation of triple-rice is often affected by erratic weather, harmful diseases and intensive farming; therefore, the use of chemical fertilizers is increasing sharply. farmers cultivating triple-rice tended to abuse pesticides and growth stimulants, which leads to increased frequency of application and spraying, with an average value of about 6.48±1.72 to 7.33±1.82 times/crop (figure 3). this result was similar to the previous studies of nhan et al. (2015), reaching 7.1±1.4 to 7.9±1.5 times/crop in the period 2011-2014. in addition, the study of nga et al. (2013) and linh et al. (2021b) for the triple-rice was reported that the frequency was about 7 – 10.2 times/crop in districts of hau giang and an giang provinces. farmers often change the pesticides after each crop, pesticides are provided based on the staff’s experience. this can lead to farmers using pesticides that are not recommended or abused, leading to many risks of pollution to the soil and water environment. durian ri6 is a tree with strong growth ability, giving fruit after about 4 years of planting, good branching, large fruit. however, this plant is often difficult to flower and susceptible to diseases and insect attacks, especially in the period from june to october when heavy rains appear (hau and hieu, 2019). durian ri6 also encounters many kinds of pests (fruit borers, planthoppers, cotton worms) and diseases (leaf burn, pink fungus, flower rot, anthracnose). besides, durian farmers handle the reverse season to solve the problem of “good harvest” with current technical advances (thao et al., 2014), so the use of pesticides in the cultivation of durian has a very high frequency. therefore, although the pesticides and active ingredients were recorded lower than that of triple-rice, the frequency of spraying reached the threshold of 61.8±9.1 times/crop which was nearly 9 times higher than that of the triple-rice model. in which, the group of pesticides that are used the most are insecticides, insecticides and fungicides, micro-organisms with the rate of 47% and 37%, respectively. other pesticides were also used, but to a lesser extent, at the same rate of 8%. the model of durian ri6 brings a lot of economic value but causes a lot of damage to environmental issues and especially to the © 2022 the authors. page 99 of 103 hong et. al. indonesian journal of environmental management and sustainability, 6 (2022) 98-103 figure 1. map of research location table 1. classification of pesticide toxicity according to who toxic group ld50 (mg/kg) oral dermal solid liquid solid liquid group i (ia, ib) ≤50 ≤200 ≤100 ≤400 group ii >50-500 >200–2000 >100–1000 >400–4000 group iii 500–2000 >2000–3000 >1000 >4000 group vi >2000 >3000 >1000 >4000 figure 2. types of pesticides and active ingredients used in production models health of producers and applicators (tuan and diem, 2018; shrestha et al., 2018; utami et al., 2020; pibul and jawjit, 2021). e-dor longan grows strongly, is easy to set fruit, has high figure 3. average frequency of spraying pesticides in triple-rice model yield, has few diseases, is easy to handle flowering and is less susceptible to insect damage (tan, 2018). the e-dor longan variety suffers only from mild broom disease, which can be handled manually, pruning infected crowns, and properly handled. the time from flowering to harvesting only takes © 2022 the authors. page 100 of 103 hong et. al. indonesian journal of environmental management and sustainability, 6 (2022) 98-103 about 126 days (hau and huan, 2011), so farmers can improve, process and cultivate two crops per year. for that reason, e-dor longan growers must ensure that the technical requirements for care and necessary nutrition are essential, so they do not have to use too many pesticides during their cultivation. farmers cultivating the e-dor longan only use pesticides when there are insects and pests that currently exceed the allowable threshold and use the correct dosage of the pesticides as recommended on the product packaging. in general, the number of active ingredients found in this study was lower than that of some previous studies (giang, 2010; tung, 2013; toan, 2013). the triple-rice farming model uses a lot of pesticides, but the level of use is much lower than the model of durian ri6. the fruit cultivation models often use a lot of pesticides in the flowering stage and especially in the reverse season. however, the e-dor longan model uses very few active ingredients and pesticides, which is consistent with current production trends and easy to meet export standards. the limited use of pesticides not only increases the value of agricultural products due to the absence of pesticide residues, ensures the health of farmers and has a positive effect on the environment. farmers may consider switching to a more suitable model to balance economic, environmental and household health factors. 3.2 the level of toxicity of the pesticides used according to the classification of the world health organization (who), the toxicity of active pesticides is divided into 4 groups, including group i (very toxic), group ii (high toxicity), group iii (danger) and group iv (carefully). in the present study, the pesticides were classified into three groups (figure 4). the result of study showed that there was no occurrence of toxic group i in the cultivation models. the toxic group iv accounted for the highest rate among the remaining groups with the rate of 37.4%, followed by the toxic group ii (33.3%) and the lowest was the toxic group iii (29.3%). in which, in the triple-rice cultivation model, there are 16 active ingredients in group ii, 15 active ingredients in group iii and the remaining 23 active ingredients in group iv. durian ri6 model recorded 15 active ingredients in group ii, 12 active ingredients in group iii and 14 active ingredients in group iv. for the e-dor longan model, the two active ingredients were classified into two different groups (group ii and group iii). compared to circular 10/2020/tt-bnnptnt on the list of pesticides allowed to be used in vietnam (ministry of agriculture and rural development , 2020), there are five banned active ingredients in the triple-rice model, namely 2.4d, paraquat, carbosulfan, trichlorfon and glyphosate. besides that, the durian ri6 model also found that the pesticides used contained banned active ingredients, including acephate and carbofuran. in addition, chlorpyrifos ethyl, fipronil has been banned under decision 501/qd-bnn-bvtv dated february 12, 2019 of the (ministry of agriculture and rural development, 2019). therefore, there were a total of four banned active ingredients in the durian ri6 model. the active ingredients used in the e-dor longan model are on the permitted list. the use of banned active ingredients will violate the regulations of the state and will cause a lot of harm to the environment and especially to human health. figure 4. classification of toxicity groups of pesticides in the study areas according to phong and thong (2018), the exposure rate of pesticides when spraying on fruit cultivation models is always higher than in rice and crop models, the vast majority of participants sprayed pesticides that are not fully equipped with protective equipment have symptoms such as fatigue, heat and itching, dizziness. at the same time, workers working at pesticide factories also contain activities toxic substances in the blood (dasgupta et al., 2007). these things show that the potential danger of pesticides to human health is very alarming. not only that, pesticides have a strong and especially serious impact on water resources (tuan and diem, 2018; shrestha et al., 2018; utami et al., 2020; pibul and jawjit, 2021; giao, 2021). along with the production area, agricultural farming models are the main and leading in the country, the mekong delta faces many problems of water pollution stemming from agricultural production activities because of the amount of pesticides used. the uses of pesticides in agricultural activities and untreated residues are easily dispersed, diluted and released into water sources (ministry of natural resources environment, 2018; selvarajah and thiruchelvam, 2007). 3.3 current management of pesticidal wastes the results indicated that about 55% of people have built warehouses to store agricultural materials for production. however, the warehouses are often built temporarily in near houses or in cultivated garden. more than 38% of people have stored pesticides at home, which have many potential risks to the environment and directly affect health. especially active ingredients that are highly toxic and difficult to decompose. approximately 22% of the remaining households use the pesticides directly after buying it or leaving it outdoors. © 2022 the authors. page 101 of 103 hong et. al. indonesian journal of environmental management and sustainability, 6 (2022) 98-103 the pesticide packaging after use was usually treated by burning or burying, selling bottles, and a small number of wastes being mixed with domestic waste (nhan et al., 2015; toan, 2013). according to the survey results, there was about 75% and 50% of farmers treated the wastes by burning and burying, respectively. these two methods were reported to be unreasonable and cause many environment consequences; however, it accounted for the highest percentage. about 22.5% of pesticide bottles and packages were collected and sold as scrap by local people and 17.5% were directly discarded into the environment without any treatment methods. the collection of pesticidal bottles has been done through local programs and companies. however, the level of effectiveness and popularity has not met expectations in many localities. for the use of pesticides left over after spraying, the majority of interviewed farmers choose to use it up and leave no residue (accounted for 70%). a small number of farmers choose to store for the next spraying (accounted for 18.3%), about 5% choose to throw away and discharge into ditches and canals. the inappropriate handling of residual pesticides by farmers leads to pesticide residues being dispersed in surface water, leading to impacts on aquatic organisms and pesticides exposure when using water for daily activities (toan, 2013; tuan and diem, 2018; shrestha et al., 2018; utami et al., 2020). 4. conclusions the triple-rice was recorded to use kind of pesticides more than that of durian ri6 and e-dor longan. in which, there were five banned active ingredients in each triple-rice and durian ri6 model. the frequency of pesticide use in the durian ri6 model was recorded the highest, followed by triple-rice and e-dor longan. the proportions of groups at levels of high toxicity, danger and carefully were about 33.3%, 29.3% and 37.4%, respectively. the methods of handling pesticidal wastes are mainly burning and burying; these practices were not meeting the requirements for protecting health and the environment. therefore, it is necessary to propagate and raise people’s awareness when using, managing and handling pesticides. 5. acknowledgment the authors gratefully appreciate the time and effort of the respondents, students and staff participating in completing the study. the opinions presented in this study are the scientific views of the authors only. references dasgupta, s., c. meisner, d. wheeler, k. xuyen, and n. t. lam (2007). pesticide poisoning of farm workersimplications of blood test results from vietnam. international journal of hygiene and environmental health, 210(2); 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(2013). evaluation of the current status of using agro-pharmaceuticals in rice production in three ecological regions of kien giang province. graduate thesis. can tho university utami, r. r., g. w. geerling, i. r. salami, s. notodarmojo, and a. m. ragas (2020). agricultural pesticide use in the upper citarum river basin: basic data for model-based risk management. journal of environmental science and sustainable development, 3(2); 235–260 © 2022 the authors. page 103 of 103 introduction materials and methods data collection classification of pesticide toxicity results and discussion current use of pesticides in some agricultural cultivating models the level of toxicity of the pesticides used current management of pesticidal wastes conclusions acknowledgment title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper evaluating groundwater quality in bac lieu province using multivariate statistical method and groundwater quality index nguyen thanh giao1*, phan kim anh1, huynh thi hong nhien1 1college of environment and natural resources, can tho university, can tho, 94000, vietnam *corresponding author e-mail: ntgiao@ctu.edu.vn abstract this study aimed to evaluate groundwater quality in bac lieu province, vietnam using multivariate statistical methods and groundwater quality indices (gwqi). eleven groundwater quality parameters including ph, chloride (cl−), total dissolved solids (tds), nitrate (n-no−3 ), ammonium (n-nh + 4 ), sulfate (so 2− 4 ), iron (fe), manganese (mn), arsenic (as), hardness and coliforms were collected at seven monitoring sites in may 2020. these parameters were compared with the national technical regulation on groundwater quality (qcvn 09-mt:2015/btnmt). cluster analysis (ca) and principal component analysis (pca) were used to elaborate on the groundwater quality variation and pollution sources. the results indicated that groundwater in the study area was polluted by n-nh+4 while other parameters were within the national regulatory limits. the high concentration of n-nh+4 could be attributed to intensive agricultural practices, especially fertilizer usage. ca results divided the monitoring sites into three clusters by the parameters of ph, n-no−3 , cl −, tds, so2−4 , fe, mn, and hardness. the results of pca revealed that the groundwater quality variation could be caused by four potential sources. the main parameters that influenced groundwater quality were ph, cl−, tds, n-no−3 , n-nh + 4 , fe, and mn. the gwqi values were in the range of 2.0-12.6, which means that groundwater quality at all studied sites is of excellent quality. preventive measures should be strictly implemented to avoid groundwater pollution since this water source is more pivotal under the effects of surface water pollution and climate change. keywords ammonium, cluster analysis, groundwater, principal component analysis received: 9 august 2021, accepted: 23 november 2021 https://doi.org/10.26554/ijems.2021.5.4.129-135 1. introduction bac lieu province, a coastal province of the mekong delta, is located in the east of the ca mau peninsula, vietnam. the province has a natural area of 266,900.08 ha. while the terrain is relatively flat and mainly situated at an altitude of about 1.2 m above sea level, the rest are dunes and some low-lying areas flooded all year round (bac lieu’s people committees, 2020). the terrain tended to slope from the coast to the inland, from the northeast to the southwest. this area has a tropical monsoon climate with two distinct seasons: the rainy season from may to november and the dry season from december to april. the hydrographic regime is directly influenced by the east sea tides that are irregular semi-diurnal tides, and part of the west sea tidal regime and the mekong river flood. the regional economic growth rate continuously increases with the average rate of 8.35%/year from 2016 to 2020. advanced technologies have been applied to local agricultural practices to improve productivity. moreover, industry and construction are also promoting their potentials and strengths to develop the regional economy, especially in renewable energy and clean energy (bac lieu’s people committees, 2020). urbanization has led to considerable population growth in urban areas, namely bac lieu city. as a result, this socio-economic growth has put great pressure on environmental quality by increasing waste generation from domestics, industries and other activities (bac lieu’s people committees, 2020). groundwater is the primary source of freshwater supply for domestic activities and industrial production in bac lieu province (bac lieu’s people committees, 2020). the province has about 104,601 drilled wells with an exploitation flow of about 257,918 m3/day. the socio-economic development will put great pressure on groundwater resources. this water source plays an even more critical role in the current context of surface water pollution and climate change impacts such as saltwater intrusion and drought (bac lieu’s people committees, 2020). therefore, groundwater quality https://doi.org/10.26554/ijems.2021.5.4.129-135 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 129-135 assessment is of great concern to scientists. for example, groundwater quality in dong thap province was evaluated, and it was found that this water source was slightly polluted in the shallow layers due to domestic activities (chan and hoa, 2005). groundwater quality in can tho city was contaminated by cod and coliform (vinh, 2018). ammonium and arsenic contamination of groundwater has been reported in an giang province (stanger et al., 2005; thu et al, 2011; phan and nguyen, 2018). nitrate was found the groundwater pollutants in china (zhang et al., 2019), india (raju and singh, 2017). previous studies have employed the national groundwater quality standards to evaluate groundwater quality. however, only a few studies have applied multivariate statistical approaches for the assessment of groundwater quality. this study assesses groundwater quality in bac lieu using multivariate statistics, including cluster analysis and principal component analysis, to determine groundwater quality characteristics and key criteria affecting groundwater quality. the current results could provide scientific information on the status of groundwater quality for management. 2. experimental section groundwater samples were collected at nine locations in bac lieu province in may 2020. these sampling locations were water supply stations in bac lieu city, chau hung town vinh loi district, hoa binh town hoa binh district, phuoc long townphuoc long district, ngan dua town hong dan district, ward 1 gia rai town, and ganh hao town dong hai district. the physio-chemical parameter of groundwater including ph, chloride (cl−), total dissolved solids (tds), arsenic (as), nitrate (n-no−3 ), ammonium (nnh+4 ), sulfate (so 2− 4 ), iron (fe), manganese (mn), hardness and coliforms were analyzed. symbols and brief descriptions of sampling locations are shown in table 1. the methods of collecting and analyzing groundwater quality samples are presented in table 2. the analysis results of groundwater quality parameters were compared with the national technical regulation on groundwater quality (qcvn 09-mt:2015/btnmt). limit values of water quality parameters are presented in table 2. the data after measurement and analysis were synthesized and processed using primer 5.2 software (primer-e ltd, plymouth, uk). based on the results of eleven groundwater parameters, monitoring sites shared with groundwater quality criteria are grouped using cluster analysis (ca) method. the principal component analysis (pca) technique identified important groundwater quality parameters by reducing the contribution of less important variables without loss of information (hajigholizadeh and melesse, 2017; varol, 2020). the groundwater quality index (gwqi) is an assessment technique that provides the aggregate influence of each quality parameter on the entire water quality. gwqi is a quantitative description of water quality and usability, expressed through a scale, which is an important parameter for zoning groundwater quality. the study calculated the gwqi values using the following equation (1): gwqi = ∑10 n=1 (qnwn)∑10 n=1 wn (1) where qn is the sub-assessment quality index corresponding to the nth parameter; vn is the test result of the nth parameter of a particular sample. wn is the weight of the nth parameter which is presented in table 3. sn is the limit values of groundwater quality specified in qcvn 09mt:2015/btnmt. gwqi classifies groundwater into five levels. gwqi from 0-20 indicates excellent (level a); from 26-50 indicates good (level b); from 51-75 indicates poor (level c); from 76-100 indicates very poor (level d) and >100 indicates inappropriate for drinking (level e). 3. results and discussion as indicated in table 4, the ph in groundwater at the survey sites ranged from 7.16 to 8.20, which was within the allowable limits of qcvn 09-mt:2015/btnmt (ph 5.58.5). previous studies showed that the ph in groundwater in an giang ranged from 6.6-7.1 (phan and nguyen, 2018), ph in groundwater in vinh chau (soc trang province, 2010) ranged from 6.9-7.7 (giao et al, 2021). this fluctuation of ph value in the study area has not adversely affected human activities and the reactions with other toxic substances. in the aquatic environment, ph affects the solubility, dilution, and activity of toxic substances (manahan, 2017). high ph is a necessary condition for arsenic to seep into groundwater (an giang people’s committees, 2015). in natural water, the ph is usually in the range of 6.0-8.5 (unicef, 2008). ammonium in groundwater at the study sites in bac lieu province was in the range of 0.4-2.7 mg/l (table 4). ammonium at all locations exceeded the allowable limit of qcvn 09-mt:2015/btnmt (1 mg/l) from 1.8 to 2.7 times, with the exception of gw5 and gw6. ammonium concentration in groundwater in an giang ranged from 0.07-2.55 mg/l (giao, 2021); in vinh chau, soc trang was 0.76-5.3 mg/l (giao et al, 2021). at monitoring wells in tra vinh, ammonium concentrations ranged from 0-7 mg/l (van be, 2007). in an giang, ammonium concentration in groundwater was detected up to 4 mg/l in some certain places where pig carcasses were buried due to african swine fever (giao, 2021). furthermore, ammonium concentration in groundwater is high due to influence from poultry, livestock, domestic waste, septic tank, and aquaculture activities (danh, 2008). mainly, in agricultural activities, fertilizer application for soil improvement and nutrient supply for plants also contributes to an increase in ammonium in groundwater. nitrate in groundwater at bac lieu ranged from 0.41-1.91 mg/l (table 4). nitrate at observation wells gw5, gw6, gw7 was significantly higher than that of other wells. it can be seen that most of the nitrogen present in groundwater in the study area is in the form of ammonium which may be © 2021 the authors. page 130 of 135 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 129-135 table 1. groundwater sampling locations code sampling sites gw1 water plant no. 1 ward 1, bac lieu city gw2 concentrated water supply station in chau hung town vinh loi district gw3 centralized water supply station in hoa binh town hoa binh district gw4 centralized water supply station phuoc long town phuoc long district gw5 concentrated water supply station in ngan dua town hong dan district gw6 centralized water supply station in ward 1 gia rai town gw7 centralized water supply station in ganh hao town dong hai district table 2. sample analysis methods and limit values of groundwater parameter unit analytical methods limit value* ph tcvn 6492:2011 5.5-8.5 cl− mg/l tcvn 6194:1996 250 tds mg/l smeww 2540b:2017 1500 as mg/l spectrophotometer 0.05 n-no−3 mg/l smeww 4500-no − 3 .e:2017 15 n-nh+4 mg/l smeww 4500nh3b&f:2017 1 so2−4 mg/l smeww 4500-so 2− 4 .e:2017 400 fe mg/l tcvn 6177:1996 5 mn mg/l hach method 8149 0.5 hardness mg/l smeww 2340c:2017 500 coliforms mpn/100 ml tcvn 6187-2:1996 3 table 3. the weight factor of groundwater parameters parameter sn 1/sn wn ph 5.5-8.5 0.12 0.0051 hardness 500 0.002 0.00008 tds 1500 0.0007 0.00003 n-no−3 15 0.067 0.03 n-no−2 1 1 0.04 fe 5 0.2 0.008 mn 0.5 2 0.08 as 0.05 20 0.8 so2−4 400 0.0025 0.0001 coliform 3 0.33 0.01 due to the lack of dissolved oxygen to convert ammonium to nitrate. the allowable limit of nitrate in groundwater is 15 mg/l according to qcvn 09-mt:2015/btnmt. the nitrate concentration in groundwater in vinh chau district, soc trang province ranges from 0.008-0.047 mg/l (giao et al, 2021). in groundwater wells in an giang, nitrate nitrogen ranged from 0.51 ± 0.42 to 1.55 ± 2.15 mg/l (giao, 2021). in monitoring wells in tra vinh province, nitrate was up to 30 mg/l (van be, 2007). nitrate in groundwater at the burial site of sick death pigs ranged from 0.011 to 2.96 mg/l (giao, 2021). the nitrate concentration in groundwater in pleiku city, gia lai is very high, in the range of 0.09-95.96 mg/l (vinh, 2018). the results indicate that groundwater in many places in vietnam has been polluted due to nutrient compounds. total dissolved solids (tds) concentrations ranged from 286 to 715 mg/l (table 4). tds at all survey sites is within the allowable limit of qcvn 09-mt:2015/btnmt (1500 mg/l). tds in groundwater in an giang fluctuated greatly, especially some wells up to 4516 mg/l (phan and nguyen, 2018), which is much higher than that found in the study area in bac lieu. the high level of tds in groundwater are mainly due to the presence of sulfate ions, iron and sometimes dissolved arsenic. © 2021 the authors. page 131 of 135 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 129-135 table 4. groundwater quality in bac lieu province parameter gw1 gw2 gw3 gw4 gw5 gw6 gw7 ph 7.99 7.16 8.11 7.25 7.35 8.03 8.2 cl− 130.5 73.7 98 175.8 221.2 22.7 65.2 tds 608 599 655 508 715 286 773 as 0 0 0 0 0 0 0 n-no−3 0.48 0.53 0.52 0.41 1.91 1.06 1.86 n-nh+4 2.7 1.9 2.2 2.2 0.7 0.4 1.8 so2−4 122.42 137.6 97.95 54.13 99.08 36.9 111.18 fe 0.094 0.062 0.041 0.109 0.084 0.063 0.119 mn 0.063 0.041 0.028 0.052 0.035 0.01 0.03 hardness 125 134 98 172 166 105 117 coliforms 0 0 0 0 0 0 0 gwqi 12.6 8.5 9.9 10.1 3.5 2 8.7 the cl− concentration in groundwater in the study area varied from 22.7 mg/l (gw6) to 221.2 mg/l (gw5) (table 4). at all locations, cl− concentration was within the allowable limit of qcvn 09-mt:2015/btnmt (250 mg/l). in vinh chau, soc trang, this concentration in groundwater ranged from 115.7 to 171.5 mg/l (giao et al, 2021). besides, cl− concentration in groundwater between 35-135 mg/l can be considered normal, when the concentration of 250-400 mg/l water will have a salty taste (unicef, 2008). therefore, the water quality in the study area is almost unaffected by salinity. however, in the gw4 and gw5 wells, the chloride concentration has exceeded the standard threshold, making it difficult to use. the sulfate concentration in groundwater ranged from 36.9 (gw6) to 137.6 mg/l (gw2) (table 4). sulfate concentration has a large variation between the study sites but is still within the allowable limit of qcvn 09-mt:2015/btnmt (400 mg/l). groundwater in locations with high chloride and sulfate concentration often leads to high tds and high hardness. the hardness in groundwater at the study area ranged from 98 mg/l (gw3) to 172 mg/l (gw4) (table 4). the hardness in groundwater wells of an giang province ranged from 220.15 ± 128.20 to 1262.5 ± 1.13 mg/l (giao, 2021). in general, the hardness in groundwater in this study is still within the allowable limit of qcvn 09-mt:2015/btnmt (500 mg/l). the hardness of water is determined by the mineral concentration in the water, mainly ca2+ and mg2+. high hardness in groundwater would degrade water quality, hence unsuitable water source for domestic purposes and costly to treat before use. the results showed that the fe concentration in groundwater ranges from 0.041 mg/l (gw3) to 0.119 mg/l (gw7) (table 4) and had considerable variation among monitoring wells. fe concentration in monitoring wells at vinh chau, soc trang ranged from 0.81 to 2.19 mg/l (giao et al, 2021); fe at wells in an giang was 0.07-2.16 mg/l (phan and nguyen, 2018). in some groundwater wells in an phu district, an giang province, fe concentration was up to 4.62 ± 6.48 mg/l (giao, 2021). fe concentration in groundwater at tra vinh ranged from 1.5 to 10 mg/l (van be, 2007). the results present that fe concentration in groundwater in bac lieu province is much lower than previous studies and still within the allowable limit of qcvn 09-mt:2015/btnmt with the permissible value of 5 mg/l. however, regular use of iron-contaminated water will cause accumulation, gradually causing significant impacts on health. fe element is often present in groundwater as soluble or complex salts due to dissolution from mineral deposits in rocks or contamination of the water surface by wastewater (manahan, 2017). the mn concentration in groundwater in the study area ranged from 0.01 mg/l (gw6) to 0.063 mg/l (gw1) (table 4). mn at all locations has a very significant difference, however, it is within the allowable limit of qcvn 09-mt:2015/btnmt (0.5 mg/l). arsenic in groundwater at monitoring wells of bac lieu province was below the detection limit. previous studies have shown that toxic metal as often occurs in groundwater. some groundwater wells in tra vinh province had as concentrations up to 60 µg/l (van be, 2007). the mean arsenic concentration in groundwater in an giang province was up to 0.55 ± 1.21 mg/l (phan and nguyen, 2018). groundwater contaminated by as has been becoming a major health risk in the mekong delta, vietnam (berg et al, 2007; winkel et al., 2011). according to berg et al (2007), arsenic concentrations in groundwater in the mekong delta ranged from 1 to 845 µg/l and averaged at 39 µg/l. this concentration was higher than the safety level for arsenic concentration in drinking water as recommended by world health organization (2008) and the vietnamese government. the occurrence of as in groundwater study in an giang province could cause carcinogenic risk for the human in which the cancer risks ranged from medium (8.66 x 10−4) to high (8.26 x 10−2) for both children and adults (phan and nguyen, 2018). as regulated by qcvn 09-mt:2015/btnmt, as is still per© 2021 the authors. page 132 of 135 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 129-135 mitted in groundwater for drinking level at 50 µg/l. due to its being highly toxic, this level is reduced to 10 µg/l for drinking water according to regulations of the eu and who. in this study, arsenic is still within the permissible limit of qcvn 09-mt:2015/btnmt. coliform was not detected in groundwater in the study area (table 4). the average coliform density in wells in an giang during the period 2006-2016 was about 693.9 mpn/100 ml (phan and nguyen, 2018). the density of coliforms at the monitoring wells of vinh chau town in 2016 and 2018 was less than 3 mpn/100 ml, but in 2017 the observed concentration of coliforms was 5 mpn/100 ml, higher than the permitted limit of qcvn 09-mt:2015/btnmt. the density of coliform in well water samples in the area affected by burying death pigs due to the epidemic (african swine fever) fluctuated considerably from 9 to 9,300 mpn/100 ml (giao, 2021). coliform in groundwater samples in 07 districts of hanoi in 2018 ranged from 0-1,100 mpn/100 ml (binh et al, 2019). according to research by sánh et al. (2010), coliforms in well water in tra vinh province were contaminated with coliform with high density from 4 to 2,400 mpn/100 ml. microbial contamination in groundwater is quite common in the mekong delta (unicef, 2008; world health organization, 2008; hoa, 2016) mainly because wells are improperly preserved (unicef, 2008; an giang people’s committees, 2015). microbiological contamination in groundwater is one of the significant risks to human health during domestic uses. the calculated gwqi in table 4 showed that groundwater quality at all sampling locations is in excellent quality, with values ranging from 2.0 to 12.6. the groundwater quality in gw1, gw2, gw3, gw4, and gw7 was worse than in gw5 and gw6. the sources of groundwater pollution in bac lieu province include over-exploitation, which contributes to the saltwater intrusion into aquifers; activities of illegally converting forest agricultural land to aquaculture land, causing salinization of land resources, pulling the saline boundary deep into the underground water exploitation zone; surface water pollution due to domestic and industrial wastewater, and aquaculture wastewater; residues of pesticides and antibiotics in agricultural and aquaculture activities accumulate for a long time in the soil according to water sources, causing impacts on underground water resources; leachate from domestic waste, outdoor areas containing waste, industrial and handicraft production waste, livestock waste that have not been thoroughly treated (bac lieu’s people committees, 2020). seven monitoring sites were divided into three clusters at the euclid distance of 4, as illustrated in figure 1. cluster 1 comprised only gw6, central water supply at ward 1, gia rai town, bac lieu province. in this cluster, ph and nitrate were found to be higher compared to the other clusters (table 5). however, the water quality in the cluster 1 was within the limit values of qcvn 09-mt:2015/btnmt. cluster 2 only included the sampling site gw4 where is figure 1. clustering groundwater quality in the study area in the central water supply at phuoc long town, phuoc long district, bac lieu province. this cluster was polluted by n-nh+4 and the groundwater quality parameters of cl −, tds, so2−4 , fe, mn, hardness were much higher than the cluster 1 (table 5). cluster 3 included the monitoring sites gw1, gw2, gw3, gw5, gw7. this cluster was polluted by n-nh+4 , and the groundwater quality parameters of cl −, tds, n-no−3 , so 2− 4 , hardness were higher than those in cluster 1 and 2 (table 5). the pca revealed that 6 pcs could explain 100% of the variation of groundwater quality in the study area (table 6). pc1, pc2, pc3, pc4 significantly caused changes in groundwater quality by 37.8%, 24.1%, 19.9% and 11.4%, respectively. pc5 and pc6 only contributed to the change in groundwater quality in the study area by 5% and 1.8%, respectively. four potential groundwater polluting sources were identified as pc1-pc4 since their eigenvalues were greater than 1 (kale et al., 2020). the weighted correlation coefficient of each pcs is used to provides information regarding the correlation between the groundwater quality variables and the potential polluting sources, hence becoming the main factors influencing groundwater quality in the study area. the weighted correlation coefficient is considered strong, moderate, and weak if the absolute value is > 0.75, 0.75-0.50 and 0.50-0.30, respectively (chounlamany et al., 2017). pc1 was weakly correlated with cl−, tds, mn and hardness (table 6). pc2 was also weakly correlated with ph, n-no−3 , so 2− 4 , hardness and moderately correlated with n-nh+4 (table 6). pc3 was weakly correlated with ph and moderately related to tds and n-no−3 . pc4 was weakly impacted by ph and so2−4 while it was moderately controlled by fe. pc5 was moderately correlated with cl− while weakly correlated to ph, so2−4 and fe. pc6 was weakly influenced by tds, n-nh+4 , so 2− 4 while it was moderately modified by mn (table 6). moreover, ph was influenced by pc1-pc5. cl− was weakly and moderately impacted by pc1 and pc5, respectively. tds was weakly correlated with pc1 and pc6 while moderately correlated with pc3. n-nh+4 was moderately influenced by pc2 and weaky influenced by pc6. so2−4 was weakly modified by © 2021 the authors. page 133 of 135 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 129-135 table 5. groundwater quality in the clusters parameters cluster 1 cluster 2 cluster 3 limit values ph 8.03 7.25 7.76 5.5-8.5 cl− 22.7 175.8 117.7 250 tds 286 508 670 1500 as 0 0 0 0.05 n-no−3 1.06 0.41 1.06 15 n-nh+4 0.35 2.15 1.82 1 so2−4 36.9 54.13 113.6 400 fe 0.06 0.11 0.08 5 mn 0.01 0.052 0.04 0.5 hardness 105 172 128 500 coliforms 0 0 0 3 table 6. key parameters influencing groundwater quality in bac lieu province parameters pc1 pc2 pc3 pc4 pc5 pc6 ph 0.31 0.324 0.305 0.409 0.455 -0.29 cl− -0.424 -0.273 0.003 -0.109 0.679 -0.179 tds -0.309 0.203 0.52 -0.218 0.188 0.482 n-no−3 0.046 -0.319 0.654 -0.004 -0.059 -0.16 n-nh+4 -0.29 0.521 -0.145 0.232 0.094 0.417 so2−4 -0.255 0.408 0.268 -0.445 -0.374 -0.379 fe -0.286 -0.134 0.257 0.7 -0.37 0.049 mn -0.472 0.206 -0.195 0.178 0 -0.542 hardness -0.415 -0.423 -0.108 0.004 -0.083 0.113 eigenvalues 3.41 2.17 1.79 1.02 0.45 0.16 %variation 37.8 24.1 19.9 11.4 5 1.8 cum.%variation 37.8 62 81.8 93.2 98.2 100 pc2, and pc4 to pc6. fe was weakly controlled by pc5, moderately correlated with pc4. mn was weakly influenced by pc1 while moderately impacted by pc6. hardness was weakly affected by pc1 and pc3. in this study, the parameters of ph, cl−, tds, n-no−3 , n-nh + 4 , fe, and mn were the main parameters influencing groundwater quality in the study area. 4. conclusions the results of this study revealed that groundwater in all sampling sites was polluted by n-nh+4 . high n-nh + 4 concentration was found in water plant no. 1, bac lieu city (gw1), chau hung town water supply center, vinh loi district (gw2), hoa binh town water supply center, hoa binh district (gw3), concentrated water supply station in phuoc long town, phuoc long district (gw4) and concentrated water supply station in ganh hao town, dong hai district (gw7). it is the result of agricultural activities, namely the overuse of fertilizers to improve the soil and provide nutrients for plants. however, the values of gwqi (2.0-12.6) showed that groundwater quality at all sampling locations is of excellent quality. ca results divided the monitoring sites into three clusters. in cluster 1, ph and nitrate were higher than those in other clusters. cluster 2 was polluted by n-nh+4 , and the parameters of cl−, tds, so2−4 , fe, mn, and hardness were much higher than cluster 1. cluster 3 was also polluted by n-nh+4 , and the groundwater quality parameters of cl−, tds, n-no−3 , so2−4 , and hardness were higher than those in clusters 1 and 2. pca revealed that 6 pcs explained 100% of the variation of groundwater quality in the study area in which pc1, pc2, pc3, pc4 significantly caused changes in groundwater quality. the main parameters influencing groundwater quality in the study area were ph, cl−, tds, n-no−3 , n-nh + 4 , fe, and mn. 5. acknowledgement the authors would like to express our sincere attitude toward the department of natural resources and environment bac lieu province for data provision. the scientific and personal views presented in this paper do not necessarily reflect the views of the data provider. © 2021 the authors. page 134 of 135 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 129-135 references berg, m., c. stengel, p. t. k. trang, p. h. viet, m. l. sampson, m. leng, s. samreth, and d. fredericks (2007). magnitude of arsenic pollution in the mekong and red river deltas-cambodia and vietnam. science of the total environment, 372(3); 413–425 binh, p.t.x, quynh, l.t.p., huong, p.t.m (2019). initial survey of microbial density in domestic 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shallow groundwater in hcmc pleiku, gia lai. journal of science and technology university of danang, 3; 116–118 winkel, l. h., p. t. k. trang, v. m. lan, c. stengel, m. amini, n. t. ha, p. h. viet, and m. berg (2011). arsenic pollution of groundwater in vietnam exacerbated by deep aquifer exploitation for more than a century. proceedings of the national academy of sciences, 108(4); 1246–1251 zhang, q., p. xu, and h. qian (2019). assessment of groundwater quality and human health risk (hhr) evaluation of nitrate in the central-western guanzhong basin, china. international journal of environmental research and public health, 16(21); 4246 © 2021 the authors. page 135 of 135 introduction experimental section results and discussion conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper energy conversion of industrial wastewater on microbial fuel cell (mfc)-based with biocatalysts and pretreatments: a review iva yenis septiariva1, i wayan koko suryawan2*, ariyanti sarwono2 1sanitary engineering laboratory, study program of civil engineering, universitas sebelas maret, jalan ir sutami 36a, indonesia 2department of environmental engineering, faculty of infrastructure planning, universitas pertamina, komplek universitas pertamina, jalan sinabung ii, terusan simprug, jakarta 12220, indonesia *corresponding author e-mail: i.suryawan@universitaspertamina.ac.id abstract the purpose of this review is to provide current information regarding industrial wastewater treatment with microbial fuel cell (mfc) technology with the addition of biocatalysts and pretreatments. moreover, this review also updates on industrial waste treatment technology with mfc technology in indonesia. industries produce waste with relatively high organic content. however, this organic material is not easily degraded by biological treatment. instead of reusing, wastewater treatment, presently, aims merely to meet standards quality. in indonesia, the reuse processes which generate energy are still rare. industries that can process and convert wastewater to energy can help the government implement sustainable development in the energy sector. one of the technologies is mfc. mfc uses anode in wastewater as a substrate source and generates electrons under anaerobic conditions. electron formation could be accelerated by adding biocatalysts such as enzymes and specific microorganisms. the process occurred in an anaerobic anode could be enhanced by increasing the substrate’s biodegradability in waste. the biodegradability can be improved by pretreatment with ozone or ultrasonic technology. in indonesia, research on industrial wastewater treatment with mfc as well as biocatalyst and pretreatment is limited. keywords mfc, waste to energy, industrial wastewater, electrochemical, anaerobic, biocatalyst received: 25 october 2020, accepted: 28 november 2020 https://doi.org/10.26554/ijems.2020.4.4.102-109 1. introduction urbanization and industrialization in developing countries like indonesia create problems in the treatment and disposal of wastewater and energy needs. this situation causes severe problems of public and environmental health, especially in the aspect of sustainable development. the sustainable development goals (sdgs) are access to clean, affordable, and sustainable energy. stakeholders need to minimize the use of fossil fuel energy and its resulting pollution. the need for fuel energy and depletion of fossil fuels has resulted in the demand for alternative energy in various research fields to find potential, economical, and the manufacture of renewable energy sources.. renewable energy development is expected to reduce the dependence on fossil fuels and to increase energy independence in each country (kaygusuz, 2012). indonesian government regulation no.79/2014 concerning national energy policy is a clear form of the government’s efforts to achieve sustainable development goals in the energy sector. this policy aims to reduce fossil fuel used by less than 25% and to increase renewable energy use by more than 23% (ramadan, 2017). renewable energy has provided great benefits, especially for electricity, including increasing economic, social, and public health value. some areas in indonesia are not entirely self-sufficient, therefore they are not covered by electricity in rural areas and, even, in urban areas. this concern could accelerate the development of alternative energy sources, such as fuel cells (sivagami, 2015; martinez-duart et al., 2015; salvi and subramanian, 2015; guo et al., 2014). in indonesia, industries is one of the largest energy users and producers of waste that are not environmentally friendly. the reduction of ecosystems and the health impacts of industrial pollutants have necessitated the development of various advanced processing technologies. processing technology applications are still limited due to high energy requirements and other chemical consumption and complex operations and maintenance. industrial waste such as agricultural, plantation, palm oil, textiles, pier, and household are ideal substrate for the production of alternative energy because it was rich with organic content. organic materials in this https://doi.org/10.26554/ijems.2020.4.4.102-109 septiariva et. al. indonesian journal of environmental management and sustainability, 4 (2020) 102-109 wastewater were highly considered in waste to energy technology. the treating process of wastewater with the method of (feng et al., 2008) microbial fuel cell (mfc) emerged as an alternative in the late 1990s. the history of this technology began in 1912, with potter as the founder (potter, 1911) . mfc is a methodology that reuses and reduces energy demand. recently, the production of valuable energy and other by-products were more critical. mfc is a system in which chemical energy is converted into electrical energy or bio-electrochemical systems (bes) by catalytic reactions of microorganisms (kondaveeti et al. (2014); logan et al. (2006)) . other bes have been developed to produce useful products, such as hydrogen (santoro et al. (2017);escapa et al. (2016)), methane (babanova et al. (2016); villano et al. (2011);van eerten-jansen et al. (2012)), or desalinated water (cao et al., 2009). many things need to be conducted before reaching the industrialization of mfcs (trapero et al. (2017); rahimnejad et al. (2015)). the implementation of industrial waste is more complicated because it has to work in more complex conditions (pant et al. (2010);pandey et al. (2016)). several innovations that can be combined are the addition of biocatalysts and pretreatments. this innovation can be used as a reference of a starting point for mfc industrialization growth, especially in indonesia. this review aims to identify the type of mfc use in the wastewater industry and the challenge of using biocatalyst waste and pretreatment in mfc applications. 2. experimental section 2.1 methods this study uses a review obtained from the google scholar database. identification was carried out using the keyword of microbial fuel cell (mfc). the data used were data from journal sources, proceedings, and dissertations. data were analyzed using descriptive. previous research results from journals, proceedings, and dissertations were compared. 3. results and discussion 3.1 previous research the mfc research that has been conducted currently focuses more on laboratory scale reactors while the application in the field is required to use a relatively large scale. several laboratory-scale research results on industrial waste have resulted in developments that have the potential to be applied in the field. the summary of this study are described in table 1. researches on the addition of the catalyst shown in table 2 are quite potential. pretreatment also has the potential to increase the value of energy conversion and waste treatment as shown in table 3. 3.2 develops scale of mfc reactor several groups have examined mfc as a reactor for wastewater treatment from the lab scale to pilot scale. upscaling to a volume of 1 m3 aimed at treating the wastewater of a brewery in yatala, queensland, australia has been carried out with satisfactory results (logan, 2010). a 105 l mfc unit pilot system was also recently implemented (zhang and he, 2015). in these examples, the primary objective is to detect compounds or degradation of organic and energy potential. the forecast for cheap electricity prices grow as the use of mfc will be a promising alternative. mfc reactor performance from operating variables such as cod, flow rate, or reactor volume might vary depending on the application and wastewater, and making it a useful tool for future assessment by potential investors in this technology (trapero et al., 2017). applications of mfc have been reported to meteorological power buoys (tender et al., 2008) and wireless temperature sensors (dewan et al. (2014);ewing et al. (2014)). other types of mfc have also demonstrated the capability of turning on environmental sensors (schievano et al. (2017);khaled et al. (2016);pietrelli et al. (2014)). several other applications have been reported, including charging mobile phones (ieropoulos et al., 2013) and on smartphones (walter et al., 2017) as well as leds for lightning (gajda et al., 2015). this particular application has been developed for trials in refugee camps and slums (ieropoulos et al., 2016). 3.3 administration of biocatalysts in mfc currently, mfc research commonly uses artificial wastewater instead of actual wastewater ( pant et al. (2010);pandey et al. (2016)). the use of mfc reactors for research was limited to a laboratory scale with a volume of less than 1 l. large scale mfc reactor has also been conducted, but the reactor with such volume only potentially degrades organic compounds in waste ( zhang and he (2015);ge et al. (2015)). in general, waste has low biodegradability but high organic content,particularly for some industries such as textiles and even metals (apritama et al., 2020). much industrial wastewater is treated in conventional ways (suryawan et al., 2019). some industrial waste, which cannot be treated conventionally, utilizes organic material contained in the waste. the conversion of waste energy could be accelerated by adding a biocatalystsuch as microorganisms (bioaugmentation). this review focuses on the addition of the enzyme from agricultural waste into the mfc reactor. agricultural wastes such as straw, rice husk, and corn could potentially produce specific enzymes that were able to accelerate the substrate degradation rate in waste. the high organic content and low bod content in industrial waste cause a low biodegradability value and leads to biological processing difficulty. thus, preliminary processing (pretreatment) are needed to increase the biodegradability of the waste. some of the mfc reactor integrated pretreatments were carried out such as ozone and ultrasonic (yusoff et al., 2013) . there was still a © 2020 the authors. page 103 of 109 septiariva et. al. indonesian journal of environmental management and sustainability, 4 (2020) 102-109 table 1. laboratory scale mfc research on industrial waste no mfc system types of industrial waste ref 1 dual-chamber with aeration and composite industrial wastewater (mohan et al., 2009) addition of potassium ferricyanide (18.6 g cod/l; 56.8 g tds/l). catholyte 2 dual-chamber mfc with the addition h2o2 added in colored wastewater and (fu et al., 2010) of the fenton system anode chamber in sequential operation. 3 mfc with dual-chamber with ozone polymer wastewater with a 165 ml volume (li et al., 2017) membrane (0.08–0.12 g/l) with a cathode of 1 m hcl and 1 m naoh. 4 dual-chamber mfc with a substrate and anodes from leather, dairy, (aswin et al., 2017) volume of 500 ml and domestic industrial wastewater. 5 single chamber with batch the substrate from the oil refinery (srikanth et al., 2016) and continuous conditions with wastewater is processed continuously. the volume of 0.25/0.20 l 6 single chamber in batch condition pharmaceutical wastewater was obtained (velvizhi and mohan, 2012) with volume 0.5/0.43 l from the massive drug manufacturing unit. 7 the anaerobic consortium obtained from a single mfc (nonmediator; full-scale anaerobic sludge blanket reactor (goud and mohan, 2011) non-catalytic graphite (uasb) operating with composite chemical electrode; open-air cathode). wastewater used as a biocatalyst in the mfc anode chamber. 8 pre-fermentation & ubfc with the waste substrate from biodiesel (sukkasem, 2013) the addition of a biocatalyst wastewater, palm oil, and seafood. 9 single chamber mfc reactor with petroleum refinery wastewater (mohanakrishna et al., 2018a)a total and working volume used as a substrate of 350 and 300 ml, respectively. and alkalinity. 10 the 4l anoxic aerobic mfc reactor (fazli et al., 2018) was used for this study. the mfc used caustic wastewater is industrial reactor was inoculated with aerobic wastewater with high cod concentration sludge and operated in continuous influenced by high sulfur content, salinity, hrt and srt mode for 20 days. 11 both the anode and cathode electrodes (jiang et al., 2011) plexiglas dual-chamber mfc pressed consist of graphite fiber brushes and to both sides of the proton exchange titanium wires that collects electrons for membrane (pem) without tubes. the external circuit.the anodic compartment of mfc is inoculated with activated sludge. 12 pome (palm oil mill effluent) organic (yogaswara et al., 2017) the design type of dual-chamber waste in the anode compartment with mfc has two chambers consisting of variations addition of escherichia coli anode and cathode compartments. and saccharomyces cerevisiae (10% v/v). each volume was 500 ml. the cathode compartment contains 200 ppm kmno4 solution and aerobically conditioned with the aid of an aerator. © 2020 the authors. page 104 of 109 septiariva et. al. indonesian journal of environmental management and sustainability, 4 (2020) 102-109 small number of research that focused on mfc substrates pretreatment and needs to be studied further, especially in the field of industrial wastewater. 3.4 mfc integrated waste pre-treatment ultrasonic waves are longitudinal mechanical waves with frequencies above 20 khz. these waves could propagate in solid, liquid, and gas mediums due to interaction with molecules and the inertia properties of the medium passed through (ramadan, 2017). industrial wastewater usually has a very low biodegradability index thereforeprocessing applications using microorganisms is a major challenge. some pretreatments are important to increase the biodegradability index (bod5/cod). the higher biodegradability index is a measure for the biodegradability increase of organic pollutant degradation. this biodegradability increase could be achieved when the cod removal is moderate, and the ozonation time is short. besides, the pretreatment process was suitable for a biodegradability index of less than 0.3 and increased it to be greater than 0.4. several studies have also shown the ozonation success in increasing the industrial wastewater biodegradability (suryawan et al. (2019); suryawan et al. (2020)). 3.5 wastewater treatment industry development with mfc along with the times, the population in the world, including indonesia, is increasing. the existence of rapid population growth demands living facilities used to meet various needs. therefore, more and more industries are being built and operating to meet people’s needs in indonesian and the world. the development of industrial centers could be followed by higher waste generation, one of which is wastewater. this industrial wastewater needs to be treated beforehand to comply with quality standards if discharged into a water body. this domestic liquid waste could be processed using the mfc system to reduce organic contaminants by degrading this organic material into electricity. for high concentration of cod, the longer the degradation process, the greater the anode compartment of the proton ions (h+) and electrons (e−) would be (haslett, 2012). various utilization of mfc technology in indonesia still focuses on domestic wastewater and leachate water. meanwhile, the utilization of industrial wastewater is still low. table 4 shows various research that utilizes industrial waste for mfc technology. dual chamber modifiedmfc technology generally dominates industrial wastewater conversion to energy. there are few reported literature on mfc using catalysts for industrial wastewater media, thus it is necessary to conduct further research using biocatalysts such as bioaugmentation with microorganisms. the findings will undoubtedly offer economic, social and environmental benefits. 4. conclusions mfc technology for wastewater treatment has not been widely developed. waste could be generated from domestic activities along with non-domestic activities, such as industries. research in mfc is mostly limited to the laboratory scale. studies using both biocatalysts and pretreatments can be potentially developed to improve the mfc technology. in indonesia, mfc work has been carried out in several industries and has produced acceptable results. however, mfc technology development needs to be furtherexplored, using biocatalysts, ozone, and ultrasonic pretreatment to compromise the challenges in current treatment technology using microorganisms. the pretreatments can improve biodegradability index (bod5/cod). microbial fuel cell technology utilizes microorganism toreduce the organic contaminants by degrading this organic substances and converting into electricity. mfc treatment uses anode in wastewater as a substrate source and generates electrons under anaerobic conditions. electron formation could be accelerated by adding biocatalysts such as enzymes and specific microorganisms. the anodic compartment of mfc technology is inoculated with activated sludge from biological treatment. references ali, m. and a. a. widodo (2019). biokonversi bahan organik pada limbah cair rumah pemotongan hewan menjadi energi listrik menggunakan microbial fuel cell. envirotek: jurnal ilmiah teknik lingkungan, 11(2); 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(2016) electron transfer mechanisms to the electricity production in microbial fuel cells was demonstrated by the physically maintaining of shewanella shewanella oneidensis oneidensis using a dialysis strain 700-550. membrane and immobilizing cells in alginate. 66-74% of the transferred electrons could be attributed to direct electron transfer. the research results that could be increasing direct electron transfer in shewanella spp are suggested as future mfc processing. 7 saccharomyces cerevisiae addition to (yogaswara et al., 2017) the pome substrate decreased the microorganisms added mfc’s performance, seen from to the pome waste a decrease in the value of substrate were electric current, electric voltage, saccharomyces cerevisiaefungi resulting in adecrease in the and escherichia coli bacteria. resulting power density. © 2020 the authors. page 106 of 109 septiariva et. al. indonesian journal of environmental management and sustainability, 4 (2020) 102-109 table 3. previous mfc research with pretreatment no type of pretreatment result ref 1 ultrasound pretreatment mfc with an electrical load > 0.6 w / ml (jiang et al., 2011)increased the total cod removal rate from 11.3% to 19.2% 2 ozone pretreatment pretreatment was carried out using ozone (yusoff et al., 2013) and microwave. ozonation was carried out for 2 and 4 hours. when 2and 4-hour samples of ozonation were introduced in the mfc reactor, the voltages were increased to more than 150 mv and 120 mv respectively. ewing, t., j. t. babauta, e. atci, n. tang, j. orellana, d. heo, and h. beyenal (2014). self-powered wastewater treatment for the enhanced operation of a facultative lagoon. journal of power sources, 269; 284–292 fapetu, s., t. keshavarz, m. clements, and g. kyazze (2016). contribution of direct electron transfer mechanisms to overall electron transfer in microbial fuel cells utilising shewanella oneidensis as biocatalyst. biotechnology letters, 38(9); 1465–1473 fazli, n., n. s. a. mutamim, n. m. a. jafri, and n. a. m. ramli (2018). microbial fuel cell (mfc) in treating spent caustic wastewater: varies in hydraulic retention time (hrt) and mixed liquor suspended solid (mlss). journal of environmental chemical engineering, 6(4); 4339– 4346 feng, y., x. wang, b. e. logan, and h. lee (2008). brewery wastewater treatment using air-cathode microbial fuel cells. applied microbiology and biotechnology, 78(5); 873– 880 fu, l., s.-j. you, g.-q. zhang, f.-l. yang, and x.-h. fang (2010). degradation of azo dyes using in-situ fenton reaction incorporated into h2o2-producing microbial fuel cell. chemical engineering journal, 160(1); 164–169 gajda, i., j. greenman, c. melhuish, and i. ieropoulos (2015). simultaneous electricity generation and microbially-assisted electrosynthesis in ceramic mfcs. bioelectrochemistry, 104; 58–64 ge, z., l. wu, f. zhang, and z. he (2015). energy extraction from a large-scale microbial fuel cell system treating municipal wastewater. journal of power sources, 297; 260–264 goud, r. k. and s. v. mohan (2011). pre-fermentation of waste as a strategy to enhance the performance of single chambered microbial fuel cell (mfc). international journal of hydrogen energy, 36(21); 13753–13762 guo, w. q., q. l. wu, s. s. yang, s. m. peng, and h. c. luo (2014). the promising resource utilization methods of excess sludge: a review. in applied mechanics and materials, volume 507. trans tech publ, pages 777–781 ibrahim, b., a. m. soleh, et al. 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an economic answer towards industrial commercialization. applied energy, 185; 698–707 van eerten-jansen, m. c., a. t. heijne, c. j. buisman, and h. v. hamelers (2012). microbial electrolysis cells for production of methane from co2: long-term performance and perspectives. international journal of energy research, 36(6); 809–819 velvizhi, g. and s. v. mohan (2012). electrogenic activity and electron losses under increasing organic load of recalcitrant pharmaceutical wastewater. international journal of hydrogen energy, 37(7); 5969–5978 villano, m., g. monaco, f. aulenta, and m. majone (2011). electrochemically assisted methane production in a biofilm reactor. journal of power sources, 196(22); 9467–9472 walter, x. a., a. stinchcombe, j. greenman, and i. ieropoulos (2017). urine transduction to usable energy: a modular mfc approach for smartphone and remote system charging. applied energy, 192; 575–581 yogaswara, r. r., a. s. farha, k. khairunnisa, m. d. pusfitasari, and a. gunawan (2017). studi penambahan mikroorganisme pada substrat limbah pome terhadap kinerja microbial fuel cell. jurnal teknik kimia, 12(1); 14–18 yusoff, m. z. m., a. hu, c. feng, t. maeda, y. shirai, m. a. hassan, and c.-p. yu (2013). influence of pretreated activated sludge for electricity generation in microbial fuel cell application. bioresource technology, 145; 90–96 zhang, f. and z. he (2015). scaling up microbial desalination cell system with a post-aerobic process for simultaneous wastewater treatment and seawater desalination. desalination, 360; 28–34 © 2020 the authors. page 109 of 109 introduction experimental section methods results and discussion previous research develops scale of mfc reactor administration of biocatalysts in mfc mfc integrated waste pre-treatment wastewater treatment industry development with mfc conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper assessment of air quality in can tho city, vietnam using cluster analysis nguyen thanh giao1* 1college of environment and natural resources, can tho university, can tho, 94000, vietnam *corresponding author e-mail: ntgiao@ctu.edu.vn abstract the study was conducted to assess the air quality of can tho city. data including meteorological factors (wind direction, wind speed, temperature, humidity) and air pollutants (tsp, so2, no2 and noise) of air quality were collected from the department of natural resources and environment of can tho city at 15 monitoring locations (kk01-kk15) in 2020. the air quality parameters were compared with qcvn 26:2010/btnmt for noise and qcvn 05:2013/btnmt for ambient air quality. the results wind speeds ranged from 0.28±0.26 to 0.83±0.59 m/s, temperature from 30.13±2.12 to 31.70±2.48 °c, and humidity from 64.16±9.13 to 78.95±3.88%. tsp, so2, no2 and noise were 171.99±44.86-265.81±18.75 µg/m 3, 15.01±2.14-45.23±5.39 µg/m3, 11.78±1.87-37.64±5.02 µg/m3, 68.73±2.48-79.54±1.95 dba, respectively. in general, air quality parameters were still within the allowable limits, except for noise. all air quality variables in the dry season were higher than those in the wet season except for humidity and wind speed. the air quality in can tho city is affected by emissions from vehicles and factories in which intersection locations, major traffic routes and industrial production areas often have higher concentrations of pollutants and noise. spatial and temporal cluster analysis showed that air quality in can tho city was spatially and seasonally changed. air monitoring should also focus on toxic air pollutants in future monitoring. the current results provide a scientific basis for future air quality management. keywords air quality, air pollutants, nitrogen dioxides, sulfur dioxides, cluster analysis received: 4 september 2021, accepted: 8 december 2021 https://doi.org/10.26554/ijems.2021.5.4.154-161 1. introduction currently, air pollution is not only a problem of a country, a region but a global problem. the health and longevity of people depend a lot on the freshness of the surrounding air, in all kinds of daily material needs for human life, air is a special necessity (chan and yao, 2008). however, the speed of urbanization along with rapid population growth has led to more pollutant emissions that affect the surrounding environment and human health (srivastava and pawaiya, 2020; guttikunda et al., 2014). human exposure to polluted air is one of the causes of serious health effects, especially in urban areas with relatively high levels of pollution (ali and athar, 2008). according to hung et al. (2018), air pollution not only affects people (especially causing respiratory diseases) but also affects ecosystems and climate change such as greenhouse effect, acid rain and ozone layer depletion, etc. urban air pollution sources arising from different sources such as traffic, industry, etc. are dominated by population growth and urbanization (özden et al., 2008). the main urban air pollutants include suflur dioxide (so2), nitrogen dioxide (no2), carbon dioxide (co), fine dust particles (pm), total suspended particulates (tsp), and ozone (o3), volatile organic compounds (vocs) (özden et al., 2008; bhanarkar et al., 2005; zhang et al., 2016). the dispersion and dilution of air pollutants are strongly influenced by meteorological conditions, especially wind speed, wind direction, temperature, humidity and barometric pressure (bridgman et al., 2002; santacatalina et al., 2011; luvsan et al., 2012). can tho is a city directly under the central government of vietnam, the most modern and developed city in the mekong delta. in addition, can tho is currently a grade i city, the economic, cultural, social, health, educational and commercial center of the mekong delta region, a central city at regional and national level join with da nang and hai phong. in the past 10 years (2009-2020), the process of urbanization has taken place rapidly and widely in can tho city. the city’s economic structure is shifting towards gradually reducing the proportion of agriculture forestry fishery, increasing industry construction and services. with the current growth rate, transportation activities, industries, handicrafts and construction activities are considered as the main sources of air pollution in can tho city. according https://doi.org/10.26554/ijems.2021.5.4.154-161 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 154-161 to bang et al. (2015), the whole city of can tho has about 8 industrial zones/clusters distributed mainly in cai rang, o mon and ninh kieu districts and traffic hotspots with large and frequent traffic which are negatively affecting the air quality of can tho city. according to shrivastava et al. (2013), air pollution caused by transportation activities accounts for about 70%. besides, chakraborty et al. (2014) also said that the leading cause of air pollution is transportation (51.4%), followed by industry (24.5%). the process of combustion of fuel creates harmful gases that affect the air such as co2, co, so2, nox, pb, ch4. this study is to assess the current state of environmental air quality in can tho city. the results provide scientific basis for the management as well as the identification of the main sources of pollution in the area. 2. materials and methods 2.1 site description can tho city has a central geographical position in the mekong delta, is the main exchange gateway of the southwest region of hau river with the long xuyen quadrangle and the southern key region between a network of rivers, interlaced canals, 75km from the east sea, 1,877 km from hanoi capital and 169 km from ho chi minh city (by road). geographic coordinates 9055’08” 10019’38” north latitude; 105013’38” – 105050’35” east longitude with contiguous position. total area of can tho city with 140,849.9 ha, accounting for 3.5% of the total area of the whole mekong delta region; the city has 09 districts, including 05 city districts (ninh kieu, binh thuy, cai rang, o mon and thot not) and 04 rural districts (phong dien, co do, thoi lai and vinh thanh) including 85 communes, wards and town with 644 hamlets. can tho has a flat topography that is slightly inclined in all directions: the height from the northeast is lower to the southwest and the height from the banks of the hau river is lower to the inland. can tho city is under the influence of tropical monsoon climate, with two distinct seasons including the rainy season (from may to november) and the dry season (from december to april next year). the average temperature at the roadside points of can tho city in 2020 ranges from 26.5-35.80 °c and the average humidity varies between 46.1-85.2%. the highest number of sunshine hours is near the end of the dry season. the highest rainfall falls in september, october and the lowest in march. 2.2 air sampling and analysis data on the air environment used in the study were collected from the department of natural resources and environment of can tho city. assessment of air quality in can tho city in 2020 through 15 monitoring locations representing areas with high traffic density and relatively large industrial scale (kk01-kk15) (table 1). specifically, including 04 traffic hotspots: nguyen van linh intersection 3/2 street, luu huu phuoc intersection hoa binh boulevard, vo van kiet nguyen van cu intersection, highway 1 – can tho bridge intersection; 02 environmental monitoring points in the inner city: le hong phong street in front of the entrance to binh thuy district administrative area, o mon district people’s committee; 04 industrial park monitoring positions: tra noc 1 and 2 industrial park, hung phu industrial park and thot not industrial park; 05 locations for monitoring the air environment in the suburbs: thot not district people’s committee, the intersection of the administrative area phong dien market, the market center of thoi lai town; people’s committee of co do district and the junction of national highway 80 provincial road 922, vinh thanh district. monitoring the composition of the air environment with a frequency of 04 times/year, corresponding to the dry season (march, december) and the rainy season (may, september). in each monitoring period, samples were collected with 3 repetitions. the air and meteorological factors used in the study included noise, total suspended particulates (tsp), suflur dioxide (so2) and nitrogen dioxide (no2), wind direction, temperature, humidity and wind speed. the criteria of meteorological factors and noise are measured directly at the field with standard methods by corresponding measuring devices (table 2). the remaining parameters such as tsp, so2 and no2 were analyzed in the laboratory of can tho city environmental and natural resources monitoring center by standard methods (table 2). 2.3 data analysis data of air environment were statistically processed by ibm spss 20.0 windows software to determine mean ± std, max, min values, comparing statistically significant differences (p<0.05) between locations and time of monitoring (dry season, rainy season). values of air environment monitoring indicators in can tho city in 2020 are compared with the national technical regulation on ambient air quality – qcvn 05:2013/btnmt and the national technical regulation on language noise (from 6 a.m. to 9 p.m.) – qcvn 26:2010/btnmt (table 2). cluster analysis is a classification method used to divide data into classes or clusters. in which, subjects with similar air characteristics are in the same group, different objects are located in different clusters (lu et al., 2011; pires et al., 2008; saksena et al., 2003). cluster analysis in the study uses the average value of the air parameters values in 4 monitoring periods at each location to group air quality by observation space. at the same time, the average value of environmental air parameters at each monitoring time (march, may, september, december) is also used to analyze the air quality cluster according to the monitoring time. the classification of objects was represented by a dendrogram. objects with smaller distances will be classified into a similarity group by ward method and euclidean distance. cluster analysis (ca) using primer 5.2 software for windows (primer-e ltd, plymouth, uk). © 2021 the authors. page 155 of 161 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 154-161 table 1. can tho city’s air environment monitoring locations no. site code coordinates brief descriptionx y 1 nguyen van linh intersection 3/2 street kk01 583123 1107986 impact from traffic activities 2 the intersection of luu huu phuoc hoa binh boulevard kk02 585624 1108981 impact from traffic activities 3 vo van kiet nguyen van cu intersection kk03 583846 1110357 impact from traffic activities 4 le hong phong street in front of the entrance to binh thuy district administrative area kk04 578877 1110649 impact from traffic activities 5 tra noc industrial park 1 kk05 577292 1117654 impacts from industrial activities, transport 6 highway 1 junction can tho bridge kk06 582666 1105618 impact from traffic activities 7 hung phu industrial park kk07 586960 1106187 impacts from industrial activities, transport 8 o mon district people’s committee kk08 568245 1117538 impact from traffic activities 9 tra noc industrial park 2 kk09 576059 1118546 impacts from industrial activities, traffic 10 people’s committee of thot not district kk10 557949 1135937 impact from traffic activities 11 thot not industrial park kk11 553246 1141021 impacts from industrial activities, transport 12 the intersection of administrative area phong dien market kk12 572485 1105667 impact from traffic activities 13 hoi lai town market center kk13 562448 1113684 impact from traffic activities 14 co do district people’s committee kk14 547156 1116105 impact from traffic activities 15 highway 80 junction provincial road 922 kk15 543400 1130102 impact from traffic activities 3. results and discussion 3.1 air quality in can tho city in 2020 3.1.1 wind direction and wind speed wind is a particularly important factor in diffusing particulates and chemical vapors in the air. according to zhang et al. (2015), the wind plays a role in transporting pollutants, the wind determines which direction the pollutant will move, making the concentration of pollutants in the upwind location higher than in the downwind position. through the monitoring process, the main wind direction in can tho city is the southeast wind (se) mainly in march and the southwest wind (nw) in may, september, and december. the results showed that the wind speed of can tho city in 2020 fluctuates from 0-1.80 m/s with the average value in four monitoring periods ranging from 0.28±0.26-0.83±0.59 m/s, respectively the lowest at position kk09 and highest at position kk03. through statistical analysis, the wind speed changes according to the observed locations with four groups of different locations with statistical significance (p<0.05) (table 3). wind speed variation over time (dry season, rainy season) is statistically significant (p<0.05) with wind speed in dry season lower than in rainy season 0.40±0.41 m/s and 0.56±0.33 m/s, respectively (table 4). according to turalıoğlu et al. (2005), wind speed is inversely proportional to the concentration of air pollutants, when the wind speed is higher, the air pollutants will be diluted by dispersion. another study by verma and desai (2008) also suggested that wind speed is the main factor governing the dispersion of pollutants in the air, when the wind speed is high, the dispersion of pollutants in the air. the air pollution is also large and when the wind speed is lower, the dispersion of air pollutants is also less. © 2021 the authors. page 156 of 161 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 154-161 table 2. methods of measurement and allowable limits of air quality parameters no. parameters analytical methods limit values qcvn 05:2013/btbnmt qcvn 26:2010/btnmt 1 temp qcvn 46:2012/btnmt 2 humidity 3 wind speed 4 noise tcvn 7878-2:2010 70 dba 5 tsp tcvn 5067:1995 300 µg/m3 6 so2 tcvn 5971:1995 350 µg/m 3 7 no2 tcvn 6137:2009 200 µg/m 3 3.1.2 temperature temperature of can tho city in 2020 ranges from 26.5035.80 °c with the average value in four monitoring periods did not much change from 30.13±2.12-31.70±2.48 °c, corresponding to the lowest temperature at kk03 and the highest at kk01. spatial temperature variation in can tho city in 2020 was not statistically significant (p>0.05) (table 3). according to table 4, the environmental temperature in can tho city has a difference between the time of monitoring in the dry and rainy seasons (p<0.05). in the dry season, the temperature is about 31.60±2.45 °c, higher than that in the rainy season 30.17±2.03 °c. in the dry season, the sun is hot, the number of hours of sunshine is more, the air temperature is higher than the rainy season. according to verma and desai (2008) reported that the difference in pollutant concentration between monitoring stations has the contribution of temperature conditions, high temperature and increased pollutant concentration. according to akpinar et al. (2008) found that there was the correlation between temperature and so2 and tsp concentrations, temperature also affects the concentration of air pollutants but it is not the main parameter affecting the diffusion of pollutants. 3.1.3 humidity in conditions of high humidity, particulate matters will stick together into large particles and fall quickly to the ground. however, microorganisms in the air grow rapidly, following dust particles that diffuse widely downwind. the results showed that the air humidity in can tho city in 2020 fluctuates relatively large from 46.10 to 85.60% with the average values in four monitoring periods was 64.16±9.1378.95±3.88%, the lowest and the highest were at kk14 and kk06, respectively. spatial humidity evolution in can tho city formed three groups of locations with statistically significant differences in humidity (p<0.05) (table 4). air humidity evolution over time (table 4), the dry season air humidity (67.93±9.09%) was lower than that in the rainy season (71.18±8.01%). in the rainy season, the temperature is low, the rainfall is high, the humidity is high. according to akpinar et al. (2008) humidity is directly proportional to the pollutant concentration, the higher the humidity, the higher the air pollutants. another study on the effect of humidity on dust concentration in baghdad city also showed that air humidity is positively correlated with pollutant concentration (al-taai and al-ghabban, 2016). conversely, humidity is also thought to be negatively correlated with pollutant concentrations because it controls the absorption of pollutants (kartal and özer, 1998). 3.1.4 noise noise in the study area of can tho city in 2020 ranges from 64.80-82.90 dba with an average of four monitoring periods at about 68.73±2.48-79.54±1.95 dba, respectively. the lowest at kk09 and the highest at kk01 and kk01 nguyen van linh intersection with 3/2 street were having many moving vehicles. there were 08/15 monitoring locations with noise exceeding the permissible limit of qcvn 26:2010/btnmt, 1.00-1.14 times. noise was divided into 7 groups of locations where it has been fouud statistical significance (p<0.05) (table 3). noise in dry season was 72.13± 3.87 dba while it was 71.05±3.67 dba in rainy season (table 4). noise in can tho city in 2020 by seasons is not statistically significant (p>0.05). former study in lao cai province also reported that noise generated by means of transport at peak hours or vehicles ranged from 66.04 to 74.63 dba (hung et al., 2018). hoa et al. (2020) revealed that noise is the main cause of air pollution in son la city at the junctions and intersections of main roads, bus stations, market gates, hospital gate or where large construction activities take place. duyen et al. (2014) showed that noise in the urban and production areas is much higher than that in the rural mountainous area. 3.1.5 total suspended particulates tsp concentration in the study area of can tho city in 2020 fluctuates in the range of 93.30-293.20 µg/m3 with the average ranging from 171.99±44.86-265.81±18.75 µg/m3. tsp was the lowest at site kk15 (the suburban area of can tho city where being less affected by means of transport and industrial and handicraft production activities than other locations) and the highest at kk01 (the intersection nguyen van linh with 3/2 street, the area with the number of vehicles moving frequently). the concen© 2021 the authors. page 157 of 161 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 154-161 table 3. mean values of air quality parameters site temp humidity wind speed noise tsp so2 no2 (°c) (%) (m/s) (dba) (µg/m3) (µg/m3) (µg/m3) kk01 31.70±2.48a 66.56±9.55ab 0.43±0.23ab 79.54±1.95g 265.81±18.75g 45.23±5.39f 37.64±5.02f kk02 30.39±2.66a 73.03±8.03bc 0.76±0.36cd 75.77±2.71f 254.49±25.01g 30.73±4.36d 25.26±3.88cd kk03 30.13±2.12a 73.07±7.35bc 0.83±0.59d 75.32±1.76f 250.94±28.01fg 29.48±8.98d 24.91±8.34cd kk04 30.79±2.35a 69.77±5.53ab 0.44±0.25abc 73.07±1.92de 231.78±56.13cdefg 32.89±19.09de 27.66±15.12cd kk05 31.02±2.50a 65.91±9.00ab 0.36±0.23ab 69.58±1.98ab 245.89±30.79efg 41.66±11.74ef 30.34±9.90cde kk06 30.46±2.34a 78.95±3.88c 0.68±0.29bcd 73.23±2.21e 216.37±57.80bcdef 28.68±8.88cd 23.53±8.01bc kk07 30.68±2.26a 67.70±7.21ab 0.55±0.40abcd 69.35±1.78ab 205.03±35.23bc 20.33±6.80abc 16.88±5.91a kk08 30.53±2.09a 71.41±9.55ab 0.43±0.39abc 71.17±1.95bcd 236.23±37.77cdefg 33.32±13.53de 25.38±9.23cd kk09 31.10±2.45a 65.44±8.37ab 0.28±0.26a 68.93±3.04a 243.26±32.66defg 40.78±14.95ef 31.62±8.33def kk10 30.91±2.81a 68.11±9.43ab 0.48±0.32abcd 71.99±1.45cde 255.85±33.72g 34.25±8.25de 27.25±7.16cd kk11 31.17±2.41a 71.63±7.23ab 0.41±0.29ab 70.33±2.92abc 244.40±28.46defg 43.22±8.61f 34.77±8.37ef kk12 30.85±2.20a 70.32±8.22ab 0.42±0.41abc 68.76±1.46a 189.65±38.91ab 17.34±5.57ab 11.78±1.87a kk13 31.07±2.35a 65.48±10.19ab 0.33±0.30a 69.36±2.30ab 209.84±38.57bcd 16.41±4.65a 13.06±2.24a kk14 31.58±2.60a 64.16±9.13a 0.46±0.36abcd 68.76±2.89a 214.94±46.46bcde 25.34±13.20bcd 17.79±8.24ab kk15 30.89±2.51a 71.81±7.06ab 0.43±0.54abc 68.73±2.48a 171.99±44.86a 15.01±2.14a 12.44±1.77a min 30.13±2.12 64.16±9.13 0.28±0.26 68.73±2.48 171.99±44.86 15.01±2.14 11.78±1.87 max 31.70±2.48 78.95±3.88 0.83±0.59 79.54±1.95 265.81±18.75 45.23±5.39 37.64±5.02 qcvn 70 dba 300 µg/m3 350 µg/m3 200 µg/m3 tration of tsp is spatially fluctuated by forming 7 groups of different positions the values of tsp statistically significantly different (p<0.05) (table 3). tsp concentration between the dry season (229.64±44.94 µg/m3) and the rainy season (228.56±45.46 µg/m3) was not statistically significant (p>0.05) (table 4). in tien yen district, quang ninh province, tsp concentration of 62-282 µg/m3 is generally lower than that in the present study. duyen et al. (2014) pointed out the particulates matters in the rural area is relatively low ranges from 62-125 µg/m3, while it was high in the crowded production activities and vehicles (105-282 µg/m3). in summary, the concentration of tsp in the study area of can tho city in 2020 is still within the allowable limit qcvn 05:2013/btnmt. 3.1.6 sulfur dioxide the so2 concentration in the study area of can tho city in 2020 varied from 11.20 to 65.50 µg/m3, the average so2 concentration in four monitoring periods ranged from 15.01±2.14-45.23±5.39 µg/m3. as showed in table 3, so2 concentration fluctuates according to the observation space with 6 groups of different positions with statistical significance (p<0.05). the so2 concentration between the dry season and the rainy season was significantly different (p<0.05) with the dry season so2 concentration (33.90±14.60 µg/m 3) was higher than the rainy season (26.72±11.71 µg/m3) (table 4). the main source of so2 emissions comes from the combustion of all sulfur-containing fuels such as oil and diesel (chen et al., 2016; wakamatsu et al., 2013). bhanarkar et al. (2005) indicated that so2 emissions from industrial sources account for about 77% of the total emissions. the daily so2 concentration in urban and industrial areas of mongolia in the period 1996-2009 was from 27.30±24.70 to 37.33±35.42 µg/m3 (luvsan et al., 2012). in the southwestern region of chengdu, china, so2 emissions are mainly from industries and thermal power plants with an average daily value of 5-61 µg/m3. so2 could be decreased due to the fuel conversion process from coal to natural gas and restrictions on the construction of houses cement machinery, ceramics and glassware factories (xiao et al., 2018). in this study, so2 concentration in the study area of can tho city in 2020 is still within the allowable limit qcvn 05:2013/btnmt. 3.1.7 nitrogen dioxide no2 concentration in the study area of can tho city in 2020 fluctuated between 9.50-52.70 µg/m3 and the mean no2 concentration in four monitoring periods ranging from 11.78±1.87 to 37.64±5.02 µg/m3. ca results showed that the no2 concentration in the study area formed 6 groups of different locations with statistical significance (p<0.05) (table 3). no2 concentration in the dry season (25.62±11.54 µg/m3) is higher than that in the rainy season (22.42±9.79 µg/m3). no2 emitted from fuel combustion, gasoline and diesel-powered vehicles, and industrial boilers (wakamatsu et al., 2013). in the kuwait region, the source of no2 emissions related to traffic activities contributes approximately 25% of the total pollution, the increase in the number of motor vehicles has caused the increase of no2 in the region. industrial activities, power plants also contribute to the trend of increasing no2 concentration (al-anzi et al., 2016). in the large city, for example hangzhou area, china, no2 concentration was found to be much higher (118.5±39.3 µg/m3) than that found in the current study area (yu et al., 2014). in short, no2 concentration in the study area of can tho city is still within the allowable limit qcvn 05:2013/btnmt. 3.2 spatial and temporal clustering air quality in can tho city the results of spatial cluster analysis in figure 1 showed that air quality in can tho city was clustered into four groups. group i include 2 monitoring locations in suburban areas (kk12 – intersection of the administrative area with phong dien market, kk15 – intersection of national highway 80 with provincial road 922) with the lowest air pollutants in the 4 groups (table 5). group ii include many locations with the most similar air quality with 7 locations (kk01 nguyen van linh intersection with 3/2 street, kk04 le hong phong street in front of the entrance to binh thuy district administrative area, kk05 tra noc 1 industrial zone, kk08 – o mon district people’s committee, kk09 © 2021 the authors. page 158 of 161 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 154-161 table 4. seasonal variation of air quality parameters parameters unit season qcvndry wet temperature °c 31.60±2.45a 30.17±2.03b humidity % 67.93±9.09a 71.18±8.01b wind speed m/s 0.40±0.41a 0.56±0.33b noise dba 72.13±3.87a 71.05±3.67a 70 tsp µg/m3 229.64±44.94a 228.56±45.46a 300 so2 µg/m 3 33.90±14.60a 26.72±11.71b 350 no2 µg/m 3 25.62±11.54a 22.42±9.79a 200 table 5. the mean values of the identified clusters parameter spatial seasonal qcvngroup i group ii group iii group iv group i group ii group iii temp. 30.87 31.03 31.11 30.33 32.3 30.9 29.85 humidity 71.06 68.4 65.78 75.01 65.4 70.47 70.39 wind speed 0.42 0.4 0.44 0.76 0.29 0.52 0.56 noise 68.75 72.09 69.16 74.77 72.41 71.85 70.28 70 tsp 180.82 246.17 209.94 240.6 239.5 219.78 226.06 300 so2 16.18 38.76 20.69 29.63 39.07 28.74 26.42 350 no2 12.11 30.67 15.91 24.57 29.05 22.19 22.17 200 figure 1. spatial clustering air quality in can tho city – tra noc 2 industrial park, kk10 – thot not district people’s committee, kk11 – thot not industrial park), these are locations with many means of transportation, including traffic routes. due to the locations in the industrial zone, most of the air pollutants in group ii are highest among all groups (table 5). group iii include 3 locations (kk07 – hung phu industrial park, kk13 – thoi lai town center, kk14 – co do district people’s committee), the area with the second lowest air environment composition after group i. group iv includes 3 locations. location (kk02 – intersection of luu huu phuoc with hoa binh boulevard, kk03 – intersection of vo van kiet with nguyen van cu and kk06 – junction of national highway 1 with can tho bridge, area with relatively high meteorological factors) compared to the rest of the groups and is the area affected figure 2. temporal clustering air quality in can tho city by vehicle noise (table 5). in general, air pollutants are affected by the size, number of vehicles and production. industrial and handicraft production in the area. figure 2 presented the results of cluster analysis of air quality over time of observation periods. the air quality formed three groups. group i (march), monitoring time at the end of the dry season, the highest temperature resulted in the lowest air humidity in the 3 groups and the highest air pollutants in all groups (table 5). group ii (december), the monitoring time is at the beginning of the dry season, the temperature is somewhat lower than the last month of the dry season, due to the influence of late-season rains and a decrease in pollutants compared to march which is still higher than that in the rainy season (table 5). group ii © 2021 the authors. page 159 of 161 giao et. al. indonesian journal of environmental management and sustainability, 5 (2021) 154-161 include the months in the middle of the rainy season (may, september), high rainfall makes the ambient temperature lower than the dry season months, the humidity is high, the pollutants are somewhat lower than the other groups (table 5). 4. conclusions the results showed that the area of can tho city is influenced by two wind directions, southwest and southeast, with wind speeds ranging from 0.28±0.26 to 0.83±0.59 m/s. the temperature in can tho city ranged from 30.13±2.12 to 31.70±2.48 °c and the humidity ranged from 64.16±9.1378.95±3.88%. in general, most of the meteorological factors in the rainy season had higher values than in the dry season, except that the temperature in the dry season is higher than in the rainy season. the air pollutants in can tho city in 2020 including tsp, so2 and no2 were still within the allowable limits of qcvn 05:2013/btnmt. noise in some locations exceeded the allowable limit of qcvn 26:2010/btnmt. the causes of noise pollution as well as some locations with high air pollutant content are concentrated at intersections, main traffic routes with many motor vehicles moving as well as industrial parks. the results of spatial cluster analysis showed that air quality in can tho city formed four groups mainly affected by traffic activities, industrial production. cluster analysis 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899–905 © 2021 the authors. page 161 of 161 introduction materials and methods site description air sampling and analysis data analysis results and discussion air quality in can tho city in 2020 wind direction and wind speed temperature humidity noise total suspended particulates sulfur dioxide nitrogen dioxide spatial and temporal clustering air quality in can tho city conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper effect of pomegranate (punica granatum l.) fraction in reducing total blood cholesterol levels and triglyceride in mice (mus muscullus l.) nurlaily agustini1*, arum setiawan2, salni2 1department bioscience program, faculty of science, sriwijaya university, jalan padang selasa 524, palembang, sumatera selatan 30139, indonesia. 2department of biology, faculty of mathematics & natural sciences, sriwijaya university. jalan raya palembang-prabumulih km 32, indralaya, indonesia. *corresponding author e-mail: laily1708@yahoo.com abstract pomegranate (punica granatum l.) will be examined by looking at the ability between pomegranate extracts or fractions, which are more effective in lowering total blood cholesterol and triglyceride levels in mice. this study aims to determine the effect pomegranate fraction of methanol water from several concentrate that can reduce the total cholesterol levels and triglyceride in mice. the research method used was an experimental method with a completely randomized design (crd) pattern. the research used 6 treatment groups, and test animals divided into 6 treatment groups namely negative control given aquades, positive control fed a high-fat diet, given simvastatin, given 25 mg/grbb pomegranate fraction of methanol water, given 50 mg/grbb pomegranate fraction of methanol water, given 100 mg/grbb of pomegranate fraction of methanol water, each treatment group will be divided into 4 male mice. based on the results of this study, the active fraction that has an effect on reducing blood cholesterol and triglyceride levels with a percentage reduction about 48% and the significance value of 0,000 <α = 0.05 is the treatment given 100mg/grbb pomegranate fraction of methanol water. keywords pomegranate, total cholesterol, and triglyceride received: 28 february 2020, accepted: 20 march 2020 https://doi.org/10.26554/ijems.2020.4.1.14-22 1. introduction along with the development of times and changes in unhealthy lifestyles ranging from unbalanced eating patterns, consumption of foods high in fat and carbohydrates, to the lack of doing sports activities, many suffer from hypercholesterolemia. increased levels of cholesterol and triglycerides in the blood increased levels of cholesterol and triglycerides in the blood cause the formation of free radicals. high cholesterol and triglyceride levels are also closely related to the increased incidence of cardiovascular disease (budiyono and candra, 2013; roslizawaty et al., 2016). hypercholesterolemia is an increase in cholesterol levels in the blood that exceeds the limits needed by the body. someone said to suffer from hypercholesterolemia when total plasma cholesterol levels exceed normal conditions, ie above 200 mg / dl. cholesterol is one part of fat as one of the nutrients the body needs and the highest calorie producer (wirawan, 2018). hypercholesterolemia is a trigger for coronary heart disease because high cholesterol causes blockages in peripheral vessels that reduce blood supply to the heart. high cholesterol can also be a trigger for hypertension and stroke (soleha, 2012). hypercholesterolemia is a trigger for coronary heart disease because of high cholesterol causes blockages in peripheral vessels that reduce blood supply to the heart. high cholesterol can also be a trigger for hypertension and stroke (alwan et al., 2009). dietary management and diet modification is one way to help reduce blood lipid levels. the recommended dietary arrangement is by limiting the consumption of foods that contain high cholesterol and fat, especially saturated fat. in addition to limiting foods that are high in cholesterol and fat, consuming foods that have benefits for lowering cholesterol levels (sundari and dieny, 2013). medicinal plants have been used a lot by humans since ancient times. the development of the times is also increasing human knowledge about pharmacology and medical science, many people turn to chemical drugs that have been tested for laboratory efficacy. over time with the development of public knowledge and awareness of the dangers posed by chemicals contained in medicines, people are encouraged to return to using traditional medicines with technological developments. more and more plants have been proven to have https://doi.org/10.26554/ijems.2020.4.1.14-22 agustini et. al. indonesian journal of environmental management and sustainability, 4 (2020) 14-22 laboratory efficacy and are guaranteed safe for consumption and cure diseases without causing side effect (aseptianova, 2019). indonesia as a country that has developed modern health services but the number of people who use traditional medicine remains high. according to the 2001 national socioeconomic survey 57.7% of the population of indonesia treated themselves without medical assistance, 31.2% of them used traditional medicinal plants and 9.8% chose other traditional methods of treatment (novitasiah et al., 2012).who recommends the use of traditional medicines in the maintenance of public health, prevention and treatment of diseases, especially for chronic diseases, degenerative diseases and cancer. who also supports efforts to improve the safety and efficacy of traditional medicines (bustanussalam, 2016). pomegranate is a fruit that comes from the middle east. the potential for antioxidants in pomegranates is very high, which is around 92% (nge et al., 2015). the function of antioxidants to inhibit the formation of degenerative diseases such as hypercholesterolemia (mutia et al., 2018). pomegranate has several active compounds namely alkaloids, flavonoids, saponins, tannins, and triterpenoids (roswiem, 2014). based on some previous studies plants containing alkaloids and flavonoids have benefits in reducing cholesterol levels (zulviana et al., 2017). so far there has not been much research on pomegranate fractions in reducing blood cholesterol and triglyceride levels. but there have been several studies on pomegranates, one of which was conducted by wahyuni et al. (2013). in that study stated that pomegranate meat can reduce blood cholesterol levels. that is due to the presence of phytosterols and some other nutritional content found in pomegranates which are anticholesterol (wahyuni et al., 2013). based on the description above, this study aims to determine the effect of pomegranate fraction in reducing blood cholesterol levels and triglyceride in mice. 2. experimental section 2.1 materials the tools used in this study are blenders, filters, measuring cups, mortars, maceration containers, rotary evaporators, separating funnels, animal cages, wood chips, animal drinking bottles, analytical scales, oral needles, sonde, paper labels, blood vessels, surgical scissors, cotton swabs, masks, rubber gloves, blood cholesterol levels and the nesco multicheck brand striptest. the materials used in this study were fresh pomegranate, 48 male strain mice, distilled water, 96% ethanol, n-hexane, ethyl acetate, used cooking oil, quail eggs, 1% cmc na, simvastatin, 70% alcohol . 2.2 experimental animals the experimental animals used were 48 male swiss webster strain mice. the mice used are around 2-3 months old and weigh about 25-40 grams originating from livestock farming in the bogor agriculture department. rat cages are first sterilized by drying them in the sun, then given wood dust as the base of the cage. after the sterile cage, male rats were immediately placed and fed with pellets and drinking distilled water ad libitum (to taste). the cage was also given a woven wire as a cover and then the rats were acclimatized for 7 days. the cage is cleaned and the sawdust is replaced every 3 days. 2.3 methods 2.3.1 sampling samples to be used are pomegranates taken from pomegranate farmers weighing 10 kg in situbondo, central java and then processed into extracts and fractions at the genetic laboratory of the faculty of mathematics and natural sciences, sriwijaya university. 2.3.2 making pomegranate ethanol extract (punica granatum l.) this study used pomegranates, sorted and washed, drained and dried for 2-3 days. after drying, simplicia is then made into powder using a blender, and sieved to get the powder. the extraction process uses maceration method which is pomegranate powder weighed then immersed with 96% ethanol for 2x24 hours then filtered and obtained liquid extract. the liquid extract obtained was concentrated by distillation using arotary evaporator at a temperature of 80 c at a speed of 30 rpm so that it is free of ethanol and produces a thick concentrated extract. then the ethanol that has been separated and then soaked again with pomegranate powder for 2 days then do it the previous way using a rotary evaporator until it gets the second concentrated extract. the second concentrated extract is then dried with a hairdryer until later the extract will be more concentrated like a paste. 2.3.3 making a pomegranate fraction (punica granatum l.) concentrated pomegranate extract was fractionated with 1 liter of n-hexane, shaken for 5 minutes. after that it is allowed to form 2 layers namely the n-hexane layer and the water layer. this treatment is repeated several times until the n-hexane layer looks clear so that the n-hexane fraction is obtained. the water layer is then fractionated with 1 liter of ethyl acetate, repeated several times as in the above treatment so that the water fraction and ethyl acetate fraction are obtained. then the water fraction is mixed with 100 ml of methanol, shaken for 5 minutes and the water methanol fraction is obtained. all n-hexane, ethyl acetate and methanol water fractions were evaporated with a rotary evaporator until a thick fraction was obtained. after getting the concentrated fraction, dry it using a hairdryer until a concentrated fraction of paste is obtained. © 2020 the authors. page 15 of 22 agustini et. al. indonesian journal of environmental management and sustainability, 4 (2020) 14-22 2.3.4 classification and induction of experimental animals the animals used in this study were 48 male swiss webster strain mice aged around 2-3 months and weighing around 25-40 grams. the experimental animals will be divided into 6 groups for preliminary tests namely negative control treatment (a0), positive control (a1), pomegranate extract (a2), pomegranate n-hexane fraction (a3), pomegranate acetate fraction (a4), water methanol fraction pomegranate (a5) and 6 groups for further tests namely negative control treatment (p0), positive control (p1), pomegranate water methanol fraction (p3), pomegranate water methanol fraction (p4), pomegranate water methanol fraction (p5). each group consists of 4 mice each. in the positive control group quail yolk was induced by 1% body weight of mice and high-fat diet foods were added. 2.3.5 dosage planning the dosages used in the preliminary test were 25 mg/grbb each in pomegranate extract, n-hexane fraction, ethyl acetate fraction, and pomegranate water methanol fraction. the treatment between the extract and the most effective fraction will be carried out further tests on the fraction that is most effective in reducing blood cholesterol levels and mice triglycerides. the dose of simvastatin for humans is 20 mg/day so the dose must be converted to mice . the dose of simvastatin for mice is 0.0026 x 20mg / x / tail = 0.052 mg / x / tail. two 10 mg simvastatin tablets were crushed until smooth and parchment paper was given 1% cmc na, pitch and measured to obtain 1 g cmc na. then give cmc na 1 g of warm water then crushed with crushed simvastatin and add 100 ml of distilled water (artha et al., 2017). 2.3.6 research test stage in the preliminary test conducted to determine the effective fraction in reducing blood cholesterol levels in mice. provision of treatment in this test will be carried out for 7 days, then only found the most effective fraction in reducing total blood cholesterol levels and the most effective fraction is what will be used for further testing stages in reducing blood total cholesterol levels and mice triglycerides. animal mice will be divided into 6 groups. each group will be divided into 4 mice and given the treatment as in table 1. the follow-up test used was the active fraction in reducing blood cholesterol levels and mice triglycerides. the active fraction used will be increased to 1, 2, and 4 times the initial test dose (25, 50, 100 mg/grbb). the treatment group in this follow-up test is the same as the treatment group in the preliminary test, which is 6 groups each divided by 4 mice. further testing was carried out for 14 days. on the 14th day the mice measured blood cholesterol levels, and on the 14th day the triglycerides were measured. further grouping of tests as in table 2. 2.3.7 measurement of total blood cholesterol levels and triglycerides measurements were made using the nesco multicheck gauge . this tool will automatically turn on when the strip is inserted and will die when the strip is removed. after the blood enters the strip, the reaction from the strip container will automatically absorb blood into the strip through the capillaries. when the striptest is filled with blood, the device will process the blood for 150 seconds to get the results of measurements of the body’s blood cholesterol levels. triglycerides measurements will be performed at the center laboratory kesahatan (bblk) palembang with sampel blood of mice. the method used is the chod-pap method. previously, the blood of mice was collected first in a test tube, then let stand for 20 minutes. after that the blood is centrifuged for 20 minutes at 3000 rpm then the serum is taken as much as 10 µl and then put into a test tube, added as much as 1000 triglyceride reaction solution and mix well using vortex. let stand for 20 minutes at room temperature and measure the absorption at a wavelength of 500 mm against the blank. standard absorption measurements are carried out in the same way as sample absorption measurements. 2.3.8 data analysis this study used a completely randomized design (crd) divided into 6 treatment groups with 4 replications. the data obtained will then be tested for normality with the kolmogorov-smirnov test , homogeneity test with levene’s , and quantitative tests for total blood cholesterol and triglyceride levels obtained by the one way anova test , if there are significant differences between treatments followed by the duncan multiple area test (wbd). 3. results and discussion 3.1 normality test and homogeneity test based on the results of the normality test using the kolmogorovsmirnov test and homogeneity test using the leven’s test that the results of the study reduced blood cholesterol levels in mice in the preliminary test that is normally distributed and homogeneous data (p> 0.05). in further tests the decrease in blood cholesterol and triglyceride levels in mice also had normal distribution and homogeneous data (p> 0.05). the results of the normality test and homogeneity test are presented in table 3 and table 4. 3.2 effectiveness of active fractions on pomegranate (punica granatum l.) in reducing total blood cholesterol levels in mice (mus muscullus l.) based on the preliminary test results, it can be seen that the effect of treatment on extracts and fractions with the avarage in the decrease in total blood cholesterol levels of mice is a0 = 165.65 mg / dl, a1 = 208.30 mg / dl, a2 = 170.91 mg / dl a3 = 177.58 mg / dl, a4 = 189.75 mg / dl, a5 = 169.65 mg / dl. then he analyzed the significance of © 2020 the authors. page 16 of 22 agustini et. al. indonesian journal of environmental management and sustainability, 4 (2020) 14-22 table 1. dose of treatment in the preliminary test group treatment treatment days 1-5 days 6-10 a0 distilled water distilled water 0.1ml/10grbb 0.1ml/10grbb a1 mdlt distilled water 0.1ml/10grbb 0.1ml/10grbb a2 mdlt 25 mg/grbb of 0.1ml/10grbb pomegranate extract a3 mdlt 25 mg/grbb of n-hexane 0.1ml/10grbb pomegranate fraction a4 mdlt 25 mg/kg body weight of 0.1ml/10grbb pomegranate ethyl acetate fraction a5 mdlt 25 mg/kgbb of pomegranate 0.1ml/10grbb water methanol fraction table 2. dose of treatment in advanced tests group treatment treatment days 1-7 days 8-14 p0 distilled water distilled water 0.1ml / 10grbb 0.1ml / 10grbb p1 mdlt distilled water 0.1ml / 10grbb 0.1ml / 10grbb p2 mdlt simvastastin drug 0.1ml / 10grbb p3 mdlt 25 mg/kgbb of pomegranate 0.1ml / 10grbb water methanol fraction p4 mdlt 50 mg/kgbb of pomegranate 0.1ml / 10grbb water methanol fraction p5 mdlt 100 mg / kgbb of pomegranate 0.1ml / 10grbb water methanol fraction table 3. normality test result of total blood cholesterol levels and triglyceride in the preliminary and advanced test research variable n p distribution total cholesterol preliminary test 24 0.18 normal advanced test 24 0.363 normal triglycerides advanced test 24 0.209 normal the data with the one way anova test which showed that the value of f = 26.316 and the value of p = 0,000. this means that the mean total cholesterol in the blood group after treatment was highly significant (p <0.05). data on the results of the study of the differences in the average reduction in total blood cholesterol levels of mice and their graphs in the preliminary test are shown in table 5 and table 4. homogenity test result of total blood cholesterol levels and triglyceride in the preliminary and advanced test research variable f p information total cholesterol preliminary test 1,508 0.237 homogeneous advanced test 0.521 0.757 homogeneous triglycerides advanced test 0.284 0.916 homogeneous figure 1. preliminary test results showed that the treatment given 25 mg/grbb of pomegranate fraction of methanol water was more effective in reducing total blood cholesterol levels in mice compared to other treatments. therefore, the study continued with increasing the dose of active fraction that is the pomegranate fraction of water methanol to 2 5, 50 and © 2020 the authors. page 17 of 22 agustini et. al. indonesian journal of environmental management and sustainability, 4 (2020) 14-22 table 5. preliminary test results of total blood cholesterol levels in mice treatment group n average ± sd a0 ( negative control ) 4 165.65 ± 5.70 a1 ( positive control ) 4 208.30 ± 7.70 a2 ( pomegranate 4 170.91 ± 4.95 extract 25 mg / grbb ) a3 ( fraction of n-hexane 4 177.58 ± 4.02 25 mg / grbb ) a4 ( 25 mg / grbb 4 189.75 ± 9.41 ethyl acetate fraction ) a5 ( 25 mg / grbb 4 169.65 ± 3.72 water methanol fraction ) figure 1. graph of average differences blood total cholesterol levels of mice after being treated in a preliminary test note: a0; negative control (not treated), a1; positive control (mdlt-induced), a2; mdlt + pomegranate extract 25 mg / grbb, a3; mdlt + n-hexane fraction 25 mg / grbb, a4; mdlt + ethyl acetate fraction 25 mg / grbb, a5; mdlt + methanol water fraction 25 mg / grbb. 100 mg / grbb then compared with the antihypercholesterol drugs namely simvastatin. 3.3 effects of pomegranate ( punica granatum .l) active fraction in lowering total blood cholesterol levels and triglycerides in mice ( mus muscullus l.) 3.3.1 total blood cholesterol levels the results of the study after the administration of the treatment with various concentrations in the treatment groups p0, p1, p2, p3, p4, and p5 showed a difference in the average amount of total cholesterol in the blood of mice after treatment. the average total cholesterol level of men cit blood is p0 = 167.69 mg / dl, p1 = 215.48 mg / dl, p2 = 166.12 mg / dl, p3 = 182.15 mg / dl, p4 = 175, 82 mg / dl, p5 = 166.71 mg / dl. the avaragetotal cholesterol level in blood of mice can be seen in table 6 and the graph in figure 2. after he analyzed the significance with the one way anova test showed that the value of f = 26.825 and the value of p = 0.000. this means that the total cholesterol in the blood of the six groups after treatment was significantly table 6. result of total blood cholesterol levels of mice after being given treatment treatment group n average ± sd p0 (negative control) 4 167.69 ± 5.87 p1 (positive control) 4 215.48 ± 10.98 p2 (simvastatin) 4 166.12 ± 5.14 p3 ( 25 mg / grbb 4 182.15 ± 6.85 water methanol fraction ) p4 ( 50 mg / grbb 4 175.82 ± 5.11 water methanol fraction ) p5 ( 100 mg / grbb 4 166.71 ± 8.14 water methanol fraction ) figure 2. graph of differences in mean levels total cholesterol of the blood of mice after treatment note: p0; negative control, p1; positive control (mdlt-induced), p2; mdlt + simvastatin, p3; mdlt + methanol water fraction 25 mg / grbb, p4; mdlt + mehanol water fraction 50 mg / grbb, p5; mdlt + methanol water fraction 100 mg / grbb different (p<0.05). in the post hoc duncan test, it was shown that the p2 treatment given simvastatin when compared with p5, p0, and p4 was not significantly different in reducing total blood cholesterol levels in mice. whereas p2, p5, po, and p4 were significantly different from the decrease in total cholesterol levels in mice. in the treatment of p5 given 100 mg/grbb of methanol waterfraction, almost comparable to the treatment of p2 given antihypercholesterolemia drugs simvastatin in giving the effect of reducing total cholesterol levels in blood of mice. pos hoc duncan’s test can be seen in table 7. based on the results above shows that the mice given 100 mg/grbb of pomegranate water methanol fraction has the effect of reducing total blood cholesterol levels which is almost comparable to the blood given simvastatin. this is because 92% of pomegranates have antioxidant content (nge et al., 2015). the presence of antioxidant compounds such as flavonoids, alkaloids, and saponins. in other treatment groups such as at doses of 25 and 50 mg / grbb the pomegranate water methanol fraction also had a decrease but this was not significant. the treatment group gave a dose of 100 mg / grbb of pomegranate water methanol fraction was able to reduce the maximum and is a dose which is appropriate compared to other doses, this reduction is almost comparable to the decrease in the treatment © 2020 the authors. page 18 of 22 agustini et. al. indonesian journal of environmental management and sustainability, 4 (2020) 14-22 table 7. post hoc duncan test effectiveness of pomegranate fraction (punica granatum l. ) againts decreased total blood cholesterol levels in mice (mus muscullus l.) treatment group n subset for alpha = 0.05 1 2 3 p2(simvastatin) 4 166 12a p5(100mg/grbb water 4 166 71a methanol fraction) p0(positive control) 4 167 69a p4(50mg/grbb water 4 175 82ab 175 82b methanol fraction) p3(25mg/grbb water 4 182 12b methanol fraction) p1 (negative control) 4 215 48c sig. 0.101 0.237 1,000 group given simvastatin which if consumed continuously has adverse side effects for the body. mechanism of flavonoid compounds can reduce total cholesterol levels by inhibiting 3hydroxy -3methyl-glutaryl-coenzymea (hmg-coa) reductase that causes a decrease in cholesterol synthesis and increases the number of ldl receptors contained in the liver cell membranes and extrahepatic tissue so that levels total cholesterol will decrease, with a decrease in total cholesterol levels, ldl which functions as a means of transporting lipids in the blood will decrease in levels (nge et al., 2015). saponins form a complex that is insoluble with cholesterol, thereby preventing the absorption of cholesterol in the small intestine. in addition, saponins reduce the absorption of bile sap by forming micelle complexes that cannot be absorbed because the molecular weight is too large (matsui et al., 2009). tannins will bind to the body’s protein and will coat the intestinal wall, so that fat absorption is inhibited. tannins in plants inhibit the absorption of cholesterol in the surface of the small intestine by reacting with mucosal protein and intestinal epithelial cells and increase the formation of gallbladder acid from cholesterol and then excreted through feces so that it will reduce cholesterol levels (mu’nisa et al., 2014). pomegranates also contain fiber and vitamin c (wahyuni et al., 2013). fiber can inhibit the absorption of cholesterol in the small intestine and ultimately will reduce the concentration of cholesterol in plasma and increase cholesterol synthesis by the liver, bile synthesis, and excretion of cholesterol through feces. therefore, food fiber has been widely used and recommended to maintain blood cholesterol concentrations to remain normal while vitamin c is mentioned that plants that have vitamin c have the potential to reduce cholesterol (hernawati, 2015; wahyuni et al., 2013). besides flavonoids, saponins, and tannins, in some literature pomegranates also contain alkaloids, and triterpenoids (roswiem, 2014). giving 100 mg/grbb of pomegranate water methanol fraction in mice is almost comparable to hypercholesterol mice given antihypercholesterol drugs in the form of simvastatin. simvastatin is a statin antihypercholesterol drug which causes side effects such as diarrhea, nausea, vomiting, headaches and body aches. while pomegranates are an alternative in reducing total blood cholesterol levels because the nutritional content of pomegranates is quite adequate as a source of vitamins. so that white pomegranate meat is safer to be used as a blood cholesterol-lowering drug compared to simvastatin drug (wahyuni et al., 2013). 3.4 triglycerides the results of the study after the administration of treatments with various concentrations in the treatment groups p0, p1, p2, p3, p4, and p5 showed that there were differences in the average amount of mice triglycerides after treatment. the average triglyceride men cit are p0 = 101.63 mg/dl, p1 = 153.02 mg/dl, p2 = 90 mg/dl, p3 = 82.48 mg/dl, p4 = 77.08 mg/dl, p5 = 74.61 mg/dl. the average of mice triglycerides can be seen in table 8 and the graph in figure 3. table 8. result of triglycerides in mice after being treated treatment group n average ± sd p0 ( negative control ) 4 101.63 ± 5.32 p1 ( positive control ) 4 153.02 ± 6.36 p2 (simvastatin) 4 90.00 ± 8.82 p3 ( 25 mg / grbb 4 82.48 ± 10.29 water methanol fraction ) p4 ( 50 mg / grbb 4 77.08 ± 8.77 water methanol fraction ) p5 ( 100 mg / grbb 4 74.61 ± 8.95 water methanol fraction ) figure 3. graph of differences in mean triglyceride of mice after treatment note: p0; negative control, p1; positive control (mdlt-induced), p2; mdlt + simvastatin, p3; mdlt + methanol water fraction 25 mg / grbb, p4; mdlt + mehanol water fraction 50 mg / grbb, p5; mdlt + methanol water fraction 100 mg / grbb. after he analyzed the significance with the one way anova test, it showed that the value of f = 50.522 and p = 0.000. this means that the mean total cholesterol in the © 2020 the authors. page 19 of 22 agustini et. al. indonesian journal of environmental management and sustainability, 4 (2020) 14-22 table 9. post hoc duncan test effectiveness of pomegranate fraction (punica granatum l. ) againts decreased triglyceride in mice (mus muscullus l.) treatment group n subset for alpha = 0.05 1 2 3 4 p5 (100mg / grbb water methanol fraction) 4 74 6175a p4 (50mg / grbb water methanol fraction) 4 77 0825a p3 (25mg / grbb water methanol fraction) 4 82 4875ab 82 4875b p2 (simvastatin) 4 90 0000bc 90 0000c p0 (positive control) 4 101 63c p1 (negative control) 4 153 02d sig. 0.218 0.215 0.62 1,000 blood of the six groups after treatment was significantly different (p<0.05). in the post hoc duncan test, it was shown that the p2 treatment given simvastatin when compared with p5, p0, and p4 was not significantly different in reducing total blood cholesterol levels in mice. whereas p2, p5, po, and p4 were significantly different from the decrease in total cholesterol levels in mice. post hoc duncan test results showed that the treatment of p5 given a pomegranate fraction of methanol water 100 mg/grbb when compared with the treatment of p4, and p3 were not significantly different to the decrease in triglyceride in mice. whereas p5, p4, and p3 were significantly different compared to treatments p2 and p0. in the treatment given pomegranate water methanol fraction from several concentrations is comparable to the decrease in the treatment given simvastatinn can be seen in table 9. based on the results of the above study, it is known that 92% of pomegranates contain powerful antioxidants (nge et al., 2015). the benefits of pomegranates in the fight against free radicals that can cause degenerative diseases have been widely studied by scientists (muflihunna et al., 2014). an increase in cholesterol levels in the blood can cause formation. free radicals are compounds that are very reactive and have unpaired electrons in their outer skin. free radicals can come from pollution, dust and can be produced from metabolic processes that can be bad (yuliani and dienina, 2015). free radicals will complement their unpaired electrons by attracting nearby macromolecular electrons such as proteins, nucleic acids and dna. macromolecules in cells if oxidized and degraded can cause damage to cells (astuti, 2012). therefore, the formation of free radicals due to oxidation of triglycerides and cholesterol can damage endothelial cells causing atherosclerosis (jufri et al., 2015). chemical content of pomegranates, namely flavonoids, palifenol and catechins as well as vitamin a and vitamin c. where compounds -this compound is a powerful antioxidant that is useful to prevent the development of free radicals in the body and repair damaged body cells (muflihunna et al., 2014). from the results of research that has been done shows that mice given 100 mg / grbb are more effective in reducing triglycerides. this is caused by the presence of antioxidant compounds such as flavonoids, alkaloids, and saponins. in other treatment groups such as at doses of 25 and 50 mg / grbb the pomegranate water methanol fraction also had a decrease but this was not significant because the treatment group gave a dose of 100 mg / grbb of pomegranate water methanol fraction was able to reduce the maximum and is a dose which is appropriate compared to other doses, this reduction is almost comparable to the decrease in the treatment group given simvastatin which if consumed continuously has adverse side effects for the body. the mechanism of flavonoid compounds can reduce triglyceride levels through increased activity of the lpl enzyme, with the increase in the enzyme vldl that carries triglycerides will hydrolyse into fatty acids and glycerol. the released fatty acids will be absorbed by muscles and other tissues, then oxidized to produce energy and adipose tissue will store them as energy reserves (mu’nisa et al., 2014). the flavonoids can inhibit fatty acid synthase (fas), which is a very important enzyme in the metabolism of fat. barriers to fas can directly reduce the formation of fatty acids, thereby reducing the formation of triglycerides (zhang et al., 2009). saponin mechanism can reduce triglyceride levels, namely by inhibiting the absorption of cholesterol and triglycerides in the intestine and increasing the reaction of bile acid formation from cholesterol then excreted through feces (arauna and aulanni’am, 2016). saponins bind with bile acids and cholesterol (from food), then form micelles that cannot be absorbed by the intestine and also inhibit the work of the lpl enzyme (rahmawati et al., 2016). saponins can inhibit the absorption of cholesterol and triglycerides in the intestine by forming insoluble complex bonds in cholesterol, binds to bile acids to form micelles and increases binding of cholesterol and triglycerides by fiber (ekananda, 2015). while tannin compounds can reduce triglyceride levels by reducing the absorption of cholesterol and triglycerides in the small intestine and increasing the excretion of bile acids (cahaya and ayu, 2017). © 2020 the authors. page 20 of 22 agustini et. al. indonesian journal of environmental management and sustainability, 4 (2020) 14-22 4. conclusions the 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(2018). uji efektivitas fraksi daun salam terhadap kadar kolesterol total tikus. jurnal mandala pharmacon indonesia, 4(1) yuliani, n. n. and d. p. dienina (2015). uji aktivitas antioksidan infusa daun kelor (moringa oleifera, lamk) dengan metode 1, 1-diphenyl-2-picrylhydrazyl (dpph). jurnal info kesehatan, 13(2); 1060–1082 zhang, s.-y., x.-f. ma, c.-g. zheng, y. wang, x.-l. cao, and w.-x. tian (2009). novel and potent inhibitors of fatty acid synthase derived from catechins and their inhibition on mcf-7 cells. journal of enzyme inhibition and medicinal chemistry, 24(3); 623–631 zulviana, e., n. rahman, and s. supriadi (2017). pengaruh pemberian ekstrak buah kelor (moringa oleifera) terhadap penurunan kadar kolestrol pada darah hewan mencit (mus musculus). jurnal akademika kimia, 6(1); 15–20 © 2020 the authors. page 22 of 22 introduction experimental section materials experimental animals methods sampling making pomegranate ethanol extract (punica granatum l.) making a pomegranate fraction (punica granatum l.) classification and induction of experimental animals dosage planning research test stage measurement of total blood cholesterol levels and triglycerides data analysis results and discussion normality test and homogeneity test effectiveness of active fractions on pomegranate (punica granatum l.) in reducing total blood cholesterol levels in mice (mus muscullus l.) effects of pomegranate ( punica granatum .l) active fraction in lowering total blood cholesterol levels and triglycerides in mice ( mus muscullus l.) total blood cholesterol levels triglycerides conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper bioremediation techniques for contaminated land: focusing on land contaminated by petroleum hydrocarbon pollutants wahyu dian silviani1 1faculty of mathematics and natural science, university of mataram, jl. majapahit no. 62 mataram *corresponding author e-mail: silviani.wahyu@gmail.com abstract oil spills on land is one of major environmental issues. the spills have been known to affect not only environment but also human health. certain bioremediation techniques, biostimulation, bioaugmentation, and land farming, have been widely applied to solve the problem. approaches using these methods, over the years, have given varying result and rate of success. generally, biostimulation and bioaugmentation are preferred since they are more practical and cost effectives compared to land farming. however, geographical structure of subsurface and competition among indigenous microorganism are of major concerns when applying biostimulation. for bioaugmentation, the ability of the new engineered microorganisms to survive the new environment and to find its way to the pollutant are also big challenges. therefore, finding the best bioremediation methods that effectively can degrade oil spill must be done carefully. in this paper, advantages, disadvantages, and limitation of the methods when applied will be discussed. keywords biostimulation, bioaugmentation, land farming, oil spill received: 21 august 2020, accepted: 26 september 2020 https://doi.org/10.26554/ijems.2020.4.3.70-77 1. introduction land contaminated by petroleum hydrocarbon is one of environmental problems that have been long causing serious impacts to both environment and human. numerous cases of oil spills containing petroleum hydrocarbons on land have been reported consistently from many countries in the world. newer cases usually occur in oil producing countries, such as in mexico where 1284 ha of soil is contaminated [1]. in nigeria, over 13 million tonnes of oil has been spilled in niger delta and contaminating food chain in the area (sam and zabbey, 2018). similar cases are also reported in libya alzien et al. (2019), kuwait mostagab et al. (2018), iraq (arbili and karpuzcu, 2018). various methods, like chemical and mechanical treatment methods have been developed over the years to find the best way to deal with the problem (okoh et al., 2019). however, the outcome of those methods applications is often environmentally unsustainable and not cost effective. as a result, alternative methods which are more economically and environmentally sustainable are preferred. bioremediation is one of them (okoh et al., 2019). this method utilizes microbes, plants, and earthworms ability to degrade various types of contaminants sinha et al. (2009). the method is economically profitable since the treatment cost is generally lower compared to other treatment methods megharaj et al. (2011). another advantage of the method is it does solve the contamination problem permanently, unlike the conventional method which usually moves the problem to other places gordon et al. (2018). this method also does not harm environment for there is no involvement of hazardous chemical (perelo, 2010a). simple maintenance and “applicable over large areas” are other factors that make bioremediation more attractive to be implemented (perelo, 2010b). in this review, focus of the discussion will be on bioremediation techniques that utilize microorganisms that already live in the soil. the techniques are biostimulation, bioaugmentation, and land farming. the techniques will be discussed using land contaminated by petroleum hydrocarbon pollutant cases. this review will be divided into three parts of discussion. the first part will discuss both environmental and health impacts of petroleum pollutants on soil. it will be followed by discussion of bioremediation methods that could work to resolve the contamination of petroleum hydrocarbon on land. advantages and disadvantages of each proposed treatment will be discussed in this part. lastly, a conclusion of this review is presented. https://doi.org/10.26554/ijems.2020.4.3.70-77 wahyu dian silviani indonesian journal of environmental management and sustainability, 4 (2020) 70-77 2. results and discussion 2.1 environmental and health effects of petroleum hydrocarbon pollutants 2.1.1 environmental effects impacts that petroleum hydrocarbon spills caused to the environment is profound. the impacts may vary depending on the amount and types of petroleum hydrocarbon contaminating the land (baker, 1970). external factors, such as time of spills as well as weathering degree, also determine level of damage petroleum hydrocarbon left on soil (baker, 1970). once petroleum hydrocarbon contaminates soil, it can damage soil properties, chemically and physically (wang et al., 2013). according to sutton et al. (2012), the presence of petroleum hydrocarbon stimulates formation of anaerobic environment in soil (sutton et al., 2012). this can happen because petroleum hydrocarbons are able to smother soil particles by preventing soil pores from getting air diffusion (sutton et al., 2012). furthermore, the hydrocarbons film can also be formed when oil is spilled on the soil (gordon et al., 2018). in addition, the presence of petroleum hydrocarbon also increases oxygen demand needed by microorganisms to decompose the oil (de jong, 1980). this could lead to the decrease number of microbial community that presents in the soil (sutton et al., 2012). petroleum hydrocarbon spills also causes soil ph rise from acidic to alkaline (yu et al., 2020). all of these factors result in the decrease of concentration level of important nutrients for plants, such as phosphorus and nitrogen, while there is possibility of concentration level of toxic compound such as mn increases de jong (1980). eventually, this could deteriorate soil physical properties and fertility, adversely harming plants living on the soil. real example of this case is when crude oil spilled in arctic region (raisbeck and mohtadi, 1974). growing tissue in this area was entirely dead and various plants and trees, like sedge and mosses, could not recover as well (raisbeck and mohtadi, 1974). de jong also finds that cereal yield decreases significantly when oil contaminated wheat field in moose jaw, saskatchewan, canada (de jong, 1980). for the cereal case, the decrease of yield specifically happened because other than factors mentioned previously; oil also prevents water from being taken up by wheat (de jong, 1980). 2.1.2 health effects studies over the years have found that petroleum hydrocarbon spills indeed cause negative impacts to human health. for example, spilled petroleum hydrocarbon on land, after contaminating top soil (gay et al., 2010), is highly possible to find its way to enter groundwater which often is source of drinking water (duffy et al., 1980). on top of that, the spills could contaminate air and live stock as well (gay et al., 2010). all these possibilities lead to the greater chance for human’s health to be affected. a number of serious illnesses have been recorded in some areas which are exposed to spilled petroleum hydrocarbon. palinkas finds that the impacts of the spills on the psychosocial environment are just as bad as the impacts on the environment (palinkas et al., 1993). people, who were exposed to the spills, were found to have higher possibility, up to 3.6 and 2.9 times to have generalized anxiety disorder and post-traumatic stress disorder (ptsd) respectively (palinkas et al., 1993). studies by lyons et al. reports that people live in the area contaminated by crude oil spills are associated with “higher depression and anxiety, self reported headache, and worse mental health” (lyons et al., 1999). other studies by campbell et al., morita et al., and janjua et al. also presents similar findings in which oil spills do worsens psychological condition of people who are exposed to the spills [campbell et al. (1994), morita et al. (1999), janjua et al. (2006)]. in addition to psychological condition, physical illnesses also are a threat in the oil contaminated places. studies done by zock et al. (2007). and rodriguez-trigo et al. show that people exposed to petroleum hydrocarbon may have higher chance to experience lower respiratory tract symptoms [zock et al. (2007), rodŕıguez-trigo et al. (2010)]. people aged between 40 and 60 have higher chance to suffer from stomach and skin cancer (gay et al., 2010). children under 10 years old are found to have higher chance to suffer hematopoietic cancers and leukemia as well (gay et al., 2010). this could be because petroleum hydrocarbon exposure to human body could induce the increase of genotoxic effects, a damaging effect on dna/rna (pérez-cadah́ıa et al., 2008). miscarriage rates are also found more significant in the area that is close to the contamination area gay et al. (2010). sam and zabbey (2018) also notes other numerous health illnesses human could suffer from oil contamination, such as genetic mutation and reproductive defects, birth defects, and many other diseases (sam and zabbey, 2018). 2.2 bioremediation technique basically bioremediation is an effort to enhance hydrocarbondegrading microorganisms’ activities in soil so the rates of natural degradation could increase to significant higher rates (atlas and cerniglia, 1995). the method is believed to be environmentally friendly, for in the right circumtances, eventually, majority petroleum hydrocarbon spilled on the soil will be degraded by the microorganism. the degradation process provides energy they need to grow and to reproduce (xu et al., 2018). some examples of native microorganism that have been identified in oil contaminated soil and are potential to be used for degradation process are acetobacteria, plantomycetes, bacteriodetes, actinobacteria, chloroflexi, pseudomonas, collimonas sp, rhodococcus coprophilus, nocardioides albus, and rhodococcus erythropolis [peng et al. (2015), saadoun et al. (2008), hamamura et al. (2006)]. however, generally, the number of these indigenous microorganisms that naturally exist in soil is less than 1% of total microbial communities (atlas and cerniglia, 1995). as a result the rate of natural degradation process by these microorganisms is very low, especially when the amount of © 2020 the authors. page 71 of 77 wahyu dian silviani indonesian journal of environmental management and sustainability, 4 (2020) 70-77 petroleum that needs to be degraded is high. there is possibility that the number of the indigenous microorganisms to increase, up to 10%, with the presence of bigger oil amount (atlas and cerniglia, 1995). nonetheless, the percentage increase does not always directly translate into higher degradation rate by the microorganism for the ratio of the oil and the microorganism will be still too low. in addition, bioremediation process always depends on various factors supporting microorganism functions, including site characteristics, moisture content, temperature, nutrients, redox potential, oxygen content, contaminant bioavailability and contaminant concentrations (adams et al., 2015). therefore, various techniques have been developed to increase the natural degradation rates of the hydrocarbon-degrading microorganisms. below, a more detailed discussion of three bioremediation methodologies, biostimulation, bioaugmentation, and land farming are provided. 2.2.1 biostimulation biostimulation is one of in situ bioremediation processes. this method tries to increase the indigenous microorganism activities by adding nutrient benyahia and embaby (2016), water, acceptors or donors of electron (megharaj et al., 2011), and oxygen (malina and zawierucha, 2007). generally, nutrient is the one that most often added. the addition of nutrient is important, especially n since it works as limiting nutrient (agamuthu et al., 2013) during bioremediation. nutrition addition is also needed since with the increase number of carbon from petroleum contaminant, nutrient concentration in the soil will also deplete faster (margesin and schinner, 2001). this means less source of food for the microorganism. less source of food means less enzyme production that is needed to degrade the contaminants (vidali, 2001). according to atlas, this method successfully increases rate of biodegradation up to three to five times compared to without the addition of nutrients (atlas and cerniglia, 1995). in addition, tyagi et al. (2010). report a better result in which degradation rate increases up to 96% when nutrient, biosolid and commercial fertilizer, are added tyagi et al. (2010). tangahu et al. also report that the use of another commercial fertilizer, npk, manged to reduce total petroleum hydrocarbon value from 8,37% tph to 4.23% (tangahu et al., 2017). however, unwanted side effects, such as euthropication, could occur. nonetheless, this method has been proven successful to enhance microorganism activities to break down hydrocarbon pollutants faster (megharaj et al., 2011), such as for alaskan oil spill in alaska in 1989 (atlas and cerniglia, 1995). the main advantage of having this method implemented is because bioremediation process utilizes the indigenous microorganisms that are already compatible with their environment and evenly distributed “within the subsurface” (adams et al., 2015). moreover, nutrients added in this method could be from both organic and inorganic substances (tyagi et al., 2010), meaning more options available to produce the nutrients. on the other hand, the main challenge when implementing this method is it relies heavily on geological structure of subsurface where the indigenous microorganisms live (jayaprakash et al., 2019). this factor should not be overlooked as the geology structure will affect whether the additives could reach the microorganisms or not. for example, impermeable and tight subsurface, like clays, will be a constraint to distribute the additives evenly in the contaminated area (adams et al., 2015). another challenge is the additives might not only promote indigenous microorganisms’ growth that can degrade petroleum hydrocarbon pollutants, but also other microorganisms which have nothing to do with the biodegradation process (adams et al., 2014). as a consequence, a competition between these two types of microorganisms often could not be avoided. 2.2.2 bioaugmentation this is a bioremediation process that utilizes non-indigenous microorganisms that is known to have the ability to break down the contaminants (megharaj et al., 2011). the microorganisms come from either genetically modified microorganisms or isolated microorganisms from the contaminated areas (tyagi et al., 2010). the addition of these microorganisms also aims to increase contaminant biodegradation rate (abdulsalam and omale, 2009). the reason is because there is possibility that the indigenous microorganism species that are available in the contaminated area cannot degrade the complex mixtures of petroleum hydrocarbon pollutant since metabolic capacities of the microorganisms is different one from another (tao et al., 2017). another reason is because the indigenous species might not work optimally due to stress triggered by the petroleum hydrocarbon contaminants (adams et al., 2015). the low number of the indigenous microorganisms could be the factor as well (adams et al., 2015). therefore, the introductions of the non-indigenous species could be a support to the indigenous species which could lead to the increase of biodegradation rate (perelo, 2010a). in order for this method to be successful, the non-indigenous species must able to degrade the petroleum hydrocarbon contaminant and make this process faster than natural decontamination rate (perelo, 2010b). the non-indigenous species should also able to survive the new harsh environment and compete with the indigenous species, as well as able to find its way to the contaminants (adams et al., 2015). this method works well to degrade petroleum contaminant having complex mixtures. with the addition of more microorganisms groups or consortia, the wider the range of hydrocarbon substrates that could be degraded. usually one group of microorganism can only degrade limited type of hydrocarbon substrates (adams et al., 2015). for instance, alcanivorax degrade linear alkanes harayama et al. (2004) and mycobacterium degrade alfalfa (shi et al., 2020). in addition, it is possible to choose exactly the right microorganisms that can work optimally to break down appropriate © 2020 the authors. page 72 of 77 wahyu dian silviani indonesian journal of environmental management and sustainability, 4 (2020) 70-77 petroleum pollutants since nowadays the microorganisms are studied well first before they are applied (shi et al., 2020). tao et al. (2017). report that a consortium consisting mainly “burkholderials order (98.1%) for degrading crude oil” [2017]. another study cited in tyagi et al. (2010) give similar result in which the use of a microbial consortium degrades diesel oil completely. however, this method also has limitations. vidali notes that usually non-indigenous microorganism fails to compete with the indigenous microorganism, leading to the failure of developing sufficient populations that can degrade the contaminant (vidali, 2001). vidali also highlights the fact that soil that has been long exposed to biodegradable organic waste, including petroleum, usually has indigenous microorganisms that can effectively degrade the waste (vidali, 2001). this means, for such a case, the addition of non-indigenous microorganisms will be futile. another challenge of using non-indigenous and engineered microorganism is there are many aspects that have yet to be fully understood when the microorganisms are released to the environment (benjamin et al., 2019). 2.2.3 land farming this method is a simple bioremediation technique which requires the excavation of contaminated soil (vidali, 2001). after the contaminated soil is excavated the soil is spread on a thin surface (dzionek et al., 2016). this soil then tilled or plowed time to time to prompt the biodegradation process aerobically (pavel and gavrilescu, 2008). by doing this, it is expected that indigenous microorganism that already exist in the contaminated soil could work on degrading the contaminants (vidali, 2001). to stimulate activities of the indigenous microorganism, nutrients and minerals are added as well (wang et al., 2016). the addition of additives in this method making this method is not that different from biostimulation method, except this method is conducted not in the original contaminated sites. in practice, this method usually is only to treat superficial soil (dzionek et al., 2016). soil must be graded and cleared first before treatment using this method is run, according to the us environmental protection agency (epa). this is done by building treatment system, placing leachate collection and installing vapor treatment facilities (pavel and gavrilescu, 2008). land farming could be an effective solution for contaminated land located in the remote areas which are far away from residential areas, for soil having “low concentration of volatile compound”, and for area that can manage all potential emission to water, air, and land (epa, 2014). to implement this method properly there are a lot of factors that must be considered, including concentration, volume and characteristic of the contaminants, area and duration for treatment, and criteria of remediation to be achieved (epa, 2014). as a result, this method would be more costly when it is done properly relative to other in situ bioremediation techniques (vidali, 2001). however, nowadays, this method is quite popular as it works well for contaminants with low concentration (dzionek et al., 2016) and cost for maintenance, monitoring and clean-up liabilities is not as expensive as it was in the past (vidali, 2001). 2.3 overall evaluation generally, in situ bioremediation process is more preferred than ex situ process. the reason is usually because cost needed for in situ treatment is lower than that of ex situ (vidali, 2001). there will be no excavation fee for in situ methodologies as the treatment is conducted on site. moreover, on site treatment could prevent the spread of pollutants to other areas because there is no excavation as well as transportation process. considering these factors, among the three methods discussed, biostimulation and bioaugmentation are the more desirable option compared to land farming. biostimulation is also well preferred since us epa has recognised it as an effective method to be implemented in the field (malina and zawierucha, 2007). ex situ method such as land farming is difficult to apply when the area contaminated by petroleum is wide and deep and located in non-remote area. thus, it can be said that in situ treatments are more beneficial in term of practicality and cost effectiveness. for biostimulation and bioaugmentation cases, both methods are effective in their own way. there are many factors that can affect the final result of these methods. numerous studies have been done over the years using these methods which give various results from time to time. for example, a study carried out by bento et al. which aims to compare bioremediation techniques, biostimulation, bioaugmentation, and natural attenuation, to remediate soil contaminated by diesel oil, shows that the three treatments give different result after 12 weeks of incubation (perelo, 2010b). soils used in this study come from california and hong kong. bioaugmentation works the best for soil from long beach, california, with the degradation rate is up to 72.7% in the light (c12–c23). biostimulation, however, does not give better result or even an equivalent result like bioaugmentation according to (perelo, 2010b). other studies using bioaugmentation to degrade petroleum contaminant gives varying result of total petroleum hydrocarbon (tph) removal from 32% to 83% (adams et al., 2015). this indicates that other factors play a significant role in determining the final result of tph removal. on the other hand, a study by xu and lu indicates that biostimulation is a better choice for bioremediation of soil contaminated by crude oil (xu and lu, 2010). they find that biostimulation treatment gives up to 61% of tph removal. wu et al. also reports that biostimulation promotes 60% tph removal compared to 34% of bioaugmentation (wu et al., 2016). similar findings is also revealed by haleyur et al., wu et al., and ortega et al. with removal efficiency of 99%, 28%, and 49-62% respectively using biostimulation technique [haleyur et al. (2019), wu et al. (2019), ortega et al. (2018)]. according to adams et al., other biostimu© 2020 the authors. page 73 of 77 wahyu dian silviani indonesian journal of environmental management and sustainability, 4 (2020) 70-77 lation studies that use tph removal rate to measure the success of bioremediation process also show a promising removal rate with tph removal from 25% up to 100% (adams et al., 2015). because biostimulation and bioaugmentation techniques give varying result, an approach to combine biostimulation and bioaugmentation to achieve better result is proposed by (sun et al., 2012). sun et al. (2012). finds that dry soil containing 375 mg of total pah in each kg could be cleaned more effectively using combination of these two techniques (sun et al., 2012). it was found that 43.9% of total pah and 55% of 4-6 ring-pah can be degraded using the combination techniques. this is far higher than degradation rate when using biostimulation and bioaugmentation separately (sun et al., 2012). safdari et al. (2018). also report combination of biostimulation and bioaugmentation gives highest tph degradation rate (89,7±0.3%) compared to individual treatment (safdari et al., 2018). however, other study carried out by abdulsalam and omale give opposite result. in their study, they measure tph removal in soil which is contaminated by motor oil (abdulsalam and omale, 2009). concentration of the oil is 40.000 ppm. they found that combination of biostimulation and bioaugmentation gives a little bit lower tph removal rate (65.2±0.25%) compared with biostimulation tph removal rate (69.2±0.05%). based on the various result given by bioaugmentation and biostimulation above, it is clear that there are various factors that affect the final result of these two techniques. concentration of contaminants is one of them. contaminants concentration in each study is different. adams et al. (2015). points out that when contaminant concentration still can be tolerated by microorganisms, biodegradation process will be more optimum and faster (adams et al., 2015). but when the concentration of contaminants is beyond “microbial tolerable limit” the rates of biodegradation will be slower and will take longer times to finish (adams et al., 2015). other factors, such as soil characteristic, scale of studies, length of studies as well as various different controls applied during studies will definitely affect how well biodegradation process proceed (perelo, 2010b). thus, comparing result of bioaugmentation and biostimulation directly cannot be done without the same condition of study. comparing one study result with others also should be done carefully by observing factors and parameters affecting the studies. 2.4 limitations due to many benefits bioremediation offers, this methodology seems like a promising way to resolve land contamination because of petroleum hydrocarbon. however, this method still has its own limitations. one of them is there is no clear bench-marking value that can be used as a standard to determine whether a bioremediation process is a success or not (megharaj et al., 2011). different studies gives different tph removal rate. some gives impressive number, up to 90% but there are other studies that give less than 50% of tph removal rate. furthermore, every study uses different contaminant concentration and length of study. therefore, it is hard to compare the success of one study to others. if there was a definite number to measure the efficacy of bioremediation technique, for example a success is when tph removal rate is x% for every y ppm of contaminants in z days, it would be easier to determine goals and process that need to be done to achieve such results. another limitation is lack of understanding regarding contaminants bioavailability (megharaj et al., 2011). this is an important factor that still needs better understanding. once pollutants enter soil, there will be sorption process, precipitation and complexation processes that determine how the pollutants will interact with soil. sorption process by soil will determine pollutants’s “susceptibility to microbial degradation”, therefore affecting how effective the process of bioremediation will run (megharaj et al., 2011). the next limitation is lack of knowledge of whether there will be impacts in the future from the addition of nutrients and genetically-engineered microorganisms to the soil (benjamin et al., 2019). the knowledge of how the addition of nutrients and geneticallyengineered microorganisms will affect ecology in the future is yet fully understood. having this kind of knowledge fulfilled will be a great advantage in improving bioremediation techniques in the future. 3. conclusions in conclusion, bioremediation technique is one of promising the solutions that can be applied to remedy land contaminated by petroleum hydrocarbon. there are two types of bioremediation, in situ and ex situ. both of these methods have been proven to be more environmentally friendly and more cost effective to solve the problem compared to technical and chemical methods. however, when in situ and ex situ methods are compared, currently in situ methods are thought as the better methodology. that is why methodology such as biostimulation and bioaugmentation are widely used in the studies that aim to degrade petroleum hydrocarbon pollutants. using these two methodologies will save more money for operational cost as well as will prevent possibilities of pollutants to spread. however, there are many factors that need to be considered in order to achieve best result of tph removal when applying biostimulation and bioaugmentation techniques. these factors include contaminant concentration and characteristics, length of study, soil condition, and many other factors. these factors also make contribution to the fact that result achieved using biostimulation should not be compared directly to result achieved using bioaugmentation. in addition taking into account these factors, to get the best rates of tph removal, limitations of bioremediation methodologies, such as the absence of bench-mark value to measure the success of tph removal, the lack of understanding of contaminant bioavailability and fate of additives and genetically-engineered microorganisms added to the soil should be recognized as well. © 2020 the authors. page 74 of 77 wahyu dian silviani indonesian journal of environmental management and sustainability, 4 (2020) 70-77 references abdulsalam, s. and a. b. omale (2009). comparison of biostimulation and bioaugmentation techniques for the remediation of used motor oil contaminated soil. brazilian archives of biology and technology, 52(3); 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tian, w. wang, q. qi, p. jiang, x. gao, f. li, h. li, and h. yu (2018). petroleum hydrocarbon© 2020 the authors. page 76 of 77 wahyu dian silviani indonesian journal of environmental management and sustainability, 4 (2020) 70-77 degrading bacteria for the remediation of oil pollution under aerobic conditions: a perspective analysis. frontiers in microbiology, 9 xu, y. and m. lu (2010). bioremediation of crude oilcontaminated soil: comparison of different biostimulation and bioaugmentation treatments. journal of hazardous materials, 183(1-3); 395–401 yu, y., y. zhang, n. zhao, j. guo, w. xu, m. ma, and x. li (2020). remediation of crude oil-polluted soil by the bacterial rhizosphere community of suaeda salsa revealed by 16s rrna genes. international journal of environmental research and public health, 17(5); 1471 zock, j.-p., g. rodŕıguez-trigo, f. pozo-rodŕıguez, j. a. barberà, l. bouso, y. torralba, j. m. antó, f. p. gómez, c. fuster, and h. v. and (2007). prolonged respiratory symptoms in clean-up workers of theprestigeoil spill. american journal of respiratory and critical care medicine, 176(6); 610–616 © 2020 the authors. page 77 of 77 introduction results and discussion environmental and health effects of petroleum hydrocarbon pollutants environmental effects health effects bioremediation technique biostimulation bioaugmentation land farming overall evaluation limitations conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper the statues, plants and animals in the region of bumiayu temple tanah abang sub district, penukal abab ilir regency sondang m. siregar1* 1 the center of archaeological research south sumatera *corresponding author e-mail: siregarsondang@yahoo.com abstract the area of bumiayu temple dates from the 9th century ad. inside the site there are 5 temples that have been restored (shown) that are temples 1,2,3,7 and 8 and 6 temples are still buried in the soil that is temple 4,5,6,8,9,10, 11. bumiayu temple has foot of the temple, although with the findings of roof components and body of the temple around the temple yard show bumiayu temple 1, 2 and 3 was once a complete building consisting of the roof, body and foot of the temple. in bumiayu temple 1 and 3 illustrated fauna in the form of statues and reliefs. while the picture of the flora found in the temple reliefs 1.3 and 8. the problems that arise are the types of flora and fauna of what is described on the statue and reliefs in the area bumiayu temple and whether the flora and fauna describes the environmental settings bumiayu site. the purpose of writing is to know the types of flora-fauna described on the statue and reliefs in the area bumiayu temple and knowing the environmental conditions in the area of bumiayu temple. the method used is qualitative method with descriptive-explanative analysis especially to analyze flora-fauna shape which is depicted on statue and relief in bumiayu temple area. the results showed that the area of bumiayu temple belong to mixed dipterocarp forests which belong to the rain forest biomes which are always wet to dry with sub-biomes of dry land rain forest. the depiction of flora reliefs such as kalpataru trees and lotus flowers and relief fauna such as snakes, parrots, monkeys, crocodiles and turtles show the ancient forest ecosystem of bumiayu and the flora and fauna are still found in the forest of bumiayu until now keywords statue, relief, flora, fauna, temple received: 29 february 2018, accepted: 6 may 2018 https://doi.org/10.26554/ijems.2018.2.2.54-63 1. introduction the temple area contained temple buildings that served as a place of religious activity of hindust and buddhist. the region are not only as a place of religious activity but also the residential location of the inhabitants, in which the community activities. the sites of hinduism and buddhism located on musi river watersheds. one of the temple located in the branch of the musi river namely lematang river that surrounded bumiayu temple, it has 75 hectares. in the area of bumiayu temple only found the leg of temple building now. formerly, bumiayu temple had body and roof of the temple but has collapsed. the ruins of bumiayu temple had body components and roof of the temple that was found around the temple grounds. in the body component and foot of the temple that was depicted a relief �ora and fauna, especially in bumiayu temple 1, 3, and 8 and also was depicted animals statues (fauna). statue is an object was made by a religious media for hinduist and buddhist. the statues of animals in bumiayu temples 1, and 3 were carved in 3 dimension forms that made of clay material. relief is paint on the panel or wall of the temple building that have 2 dimensions form. the relief contained ornaments as decoration which is a symbolic value for the community maker. ornaments derived from latin language is ornare (to adorn), while in english is an ornament obtained by imitating or developing forms. ornaments consisted of 2 types ornaments/decorative ornaments and decorative decoration. decorative architecture is an ornament that must exist in the temple, because if no one can disturbed the temple building structures such as niches, ante�ks, makara, kala while decorative ornaments are functioning to give the beauty and symbols. the statues of animals and the reliefs of �ora and fauna in the region of temple bumiayu not only have a religious-related meaning but can also give an overview of the environment at that time. the problems that arise are the types of �ora and fauna of what is described in the statue and reliefs in the region temple bumiayu, how the statue and reliefs depict the environmental conditions in the region temple bumiayu. the purpose of this study is to a) identifying �ora-fauna depicted https://doi.org/10.26554/ijems.2018.2.2.54-63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 on the statue and reliefs in the area of temple bumiayu, b) knowing environmental conditions included the �ora-fauna that grow in the complex of bumiayu temple and c) knowing environmental conditions in the area of temple bumiayu. while the bene�ts of this research are a) data donation for the science of �ora-fauna living in temple bumiayu area, b) development of environmental-archeology study in indonesia and c) reference for research of endemic �ora-fauna in south sumatra. so far, research in the region of temple bumiayu focuses on the architecture of the temple building and the identi�cation of the statues of the gods connecting the temple as a hindu worship building. while this research focuses on semiotic study of the reliefs of �ora and fauna that become ornaments on the reliefs of temple panels 1 and 3 bumiayu. by studying semiotics was expected known setting of environment of temple bumiayu. 2. experimental section the method used in this research is qualitative method with explanative study especially using semiotic study. semiotic study is to review data based on markers and markers. the marker is the real meaning that the data describes while the marker is the symbolic meaning of the data. the research steps are data collection, processing and interpretation. stage of data collection by collecting data of books both books, journals and previous research reports. in addition, the recording, measurement and documentation of artifact are panels of bumiayu temple containing relief �ora and fauna. the �rst research data source is artifact, while the second data source is the environment of bumiayu village, which the area of bumiayu temple that supported the existence of the research site. furthermore, the data processing stage is descriptive and describes the data. the source of artifact data is the identi�cation of the name of the �ora and fauna described in the relief panels. while the environmental data source, referring to environmental information, made by bapeda pali is in the book of penukal abab lematang ilir (pali) in the number of year 2015. after identi�cation of data then comparated between data artifacts and environmental data so that drawn conclusion from result of comparison. this method is a combination of two disciplines into environmental archeology in particular examines the environment and culture supported by artifact and environmental sources. the tools used in the research are stationery, global position system (gps) to know the position of the �ndings in the map, measuring instruments (roll meters), and documentation tools (camera, handycam) and computer. 3. results and discussion 3.1 the region of bumiayu temples the region of bumiayu temples located in bumiayu village, tanah abang sub district, regency of penukal abab ilir. this area is now proposed to be a national heritage area. inside the area there are temples 1,2,3,4,5,6,7,8,9,10,11. among figure 1. lotus flower (variation 1) from bumiayu temple 1 figure 2. lotus flower (variation 2) from bumiayu temple 3 the 11 temples, there are 3 complexes of complexes, namely complexes of bumiayu 1, 2 and 3. regimental areas of bumiayu have long been studied by both domestic researchers and overseas researchers with various studies. e.p. tombrink �rst reported on the existence of the bumiayu site in 1864 in hindoe monumenten in de bovenlanden van palembang. in his report he mentioned that in the area of lematang ulu found the remains of 26 statues of trasit shaped nandi. in the area of lematang ilir found the ruins of the temple near the tanah abang sub district is also a relief of the parrots kept now in the national museum (tombrink, 1864). furthermore the dutch controller named a.j. knaap in 1904 reported that in the area of lematang found the ruins of brick buildings as high as 1.75 m (knaap, 1904). based on information the building is allegedly former palace of kedebong invite © 2018 the authors. page 55 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 figure 3. lotus flower (variation 3) from bumiayu temple 3 which has the area from babat to modong. j.l.a. brandes in 1904 conducted a research on the site of bumiayu, but did not produce anything (brandes, 1902). bosch in oudheidkundig verslag (ov) magazine reported that in tanah abang found the corner of the building with gana creature decoration from terracotta material, but also found the top of the building in the form of phallus, antephix, and a statue without head (bosch, 1930). in the 1936, f.m. schnitger conducted research and managed to �nd 3 collapsed brick buildings, shattered statues of shiva, 2 heads of kala, fragments of status of lions, and some brick that has a bird’s ornament. f.m. schnitger keeps these �ndings at badaruddin ii museum, palembang (schnitger, 1937). in the 1973 the center of archaeological research national (pusat penelitian arkeologi nasional) conducted research on the bumiayu site in collaboration with the university of pennsylvania. the study found three ruins of brick buildings. then they survey on the site of bumiayu and found 3 ruins of brick building. in 1990 the research was conducted more vigorously and established cooperation with ecole francaise d’extreme orient (efeo). in 1991 a comprehensive mapping of biological and geological research was conducted at the complex of bumiayu temple. the results show that the area of temple bumiayu is surrounded by a moat that �ows into the lematang river. meanwhile, from the observation of the estimated geological location of bumiayu enshrinement complex is on the meander lematang river, allegedly within 20 years will be lost because dragged by the river �ow. based on the results of the research, he then performed excavations at temple bumiayu 1 by the center of archaeological research national (puslitarkenas). in this study found the viewer corner of the temple building. in addition there are reported nine mounds of land that indicate therein contains a brick building collapse. puslitarkenas then gives numbering on the mounds. numbering is sorted in order of discovery and placed in the bumiayu temple complex situation map. the naming of "temple" on each mound does not indicate that the mound is a temple building, because from the results of the study note that not all ancient buildings contained in this site are sacred, but some are profane (utomo, 1993). bumiayu site was surrounded the branch of lematang river like the piyabung river, lebak jambu river, lebak tolib river, lebak panjang river, lebak siku river and the little siku river. the rivers are interconnected and form a moat surrounding the complex of bumiayu temple. next siku river empties into lematang river (purwanti, 1996). once opened mounds of soil in the area temple bumiayu, it have known to contain sacred buildings and profane buildings. the sacred building means the sacred building (temple) consists of the bumiayu 1, 2 and 3 temple complex. the profane building has the supporting building of the temple’s temples 4, 5, 6, 7, 8, 9 and 10. bumiayu temple 5 has many statues and the components of bumiayu temple than the other temple in bumiayu site (budisantoso, 2000). bumiayu temple was built in two stages. the �rst stage in the 9th century, namely the construction of bumiayu temple 1 with the statues made from white stone (tufa) and the construction of bumiayu temple 2. the second stage was built in the 13th century, namely the addition of pilasters bumiayu temple 1 and the construction of bumiayu temple 3 (satari, 2002). bumiayu site was built in the 9th century ad; this is evidenced by the relative dating of old ceramic �ndings. on the banks of the lematang river was found gold inscriptions (suwarnnapattra), the terms of paleography was estimated from the 10th-12th century (kartoatmodjo and soekarto, 1993), in that time there was a group of hinduist who worshiped to the god shiva in temple 1. then in the 13th century ad, the region temple bumiayu in�uenced the �ow of tantris, this is evidenced by the depiction of the statues of gods who adored tantris tribe in the form of giant in the form is creepy on the temple 3. in the area temple bumiayu depicted �ora on the temple reliefs at buiayu temple 1, 3 and 8 and fauna on the statues and reliefs at bumiayu temple 1 and 3. the existence of the image of �ora and fauna is very interesting to be studied because in addition to known the types of �ora-fauna that can be described also reveal the meaning of religion and the symbol of bumiayu temple region. 3.2 typesoffloraandfaunadescribedintheregiontemple bumiayu 3.2.1 flora types described on temple panels 1. kalpataru tree a frequent depiction of kalpataru trees found in the relief is composed of three branch or �ve branches and so on (ratnawati, 1989). kalpataru tree was depicted in the decorative reliefs and ante�x in bumiayu temple. bumiayu temple 3 has kalpataru tree in 4 variations: 1) variation 1 kalpataru tree became a roof ornament of the temple (ante�x) with size 22 cm, width 16 cm, thickness 14 cm. kalpataru tree is depicted in the form of a hump above which is decorated with leaf tendrils that form a triangular plane. b) variation 2 kalpataru tree became a temple roof ornament (ante�x) which is depicted with the shape of the cobs that emit the tendrils that form a �ve-inch square; size height 17 cm, width © 2018 the authors. page 56 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 16 cm, and thickness 7 cm. c) variation 3 kalpataru tree to be a roof ornament of the temple (ante�x) is a cob in which decorated with concentric decoration. from the exit stalks and then ends with a decoration of leaf tendrils that adorn the left and right side of the fault; size 18 cm high, 16.5 cm wide and 20 cm thick. d) variation 4 kalpataru tree to be a roof ornament of the temple (ante�x) is a cob that resembles a vase of �owers with a spherical-shaped basin with leaf tendrils on it; size 26 cm, width 18 cm and 14.5 cm thick. e) variation 5 kalpataru tree becomes a temple relief panel temple 3 bumiayu is a bonggol that emulates leaf tendrils on the left and right. the size is 30 cm height, 60 cm wide and 20 cm thick. f) variation 6 kalpataru tree became a temple relief panel temple 3 bumiayu is a �ower bunch of ceplok �ower on the left and right. unfortunately the picture of �owers frost on the left of the cob has broken; the size 30 cm long, 40 cm wide and 20 cm thick. g) variation 7 kalpataru tree became relief panel on bumiayu temple 3 is a tree �anked with lotus �owers on the left and right and the tree has 3 branches whose leaves stretching upwards. kalpataru tree is depicted in the decoration of (ante�x) and relief on temple 3 bumiayu. kalpataru derived from the word kalp which means want or desire, which is the tree, can grant all the wishes of humans who worship him. according to indian mythology, the kalpataru tree has green leaves, �owering beautifully and smells fragrant, fruiting, and full of various stones, has hundreds of gold chains, and a string of pearls that hangs on its branches (muhajirin, 2010). kalpataru found on written sources in indonesia as written in the inscription yupa, mentioned that relics of the king mulawarman kalpataru writing is also mentioned in the tantu story of the singing there is a place called hiranyapura many overgrown kalpataru trees. kalpataru tree depiction is also often encountered in reliefs consisting of three branches, �ve branches and even no branches (istanto, 2017). in temple 3 bumiayu found kalpataru tree on ante�x ornament and relief which still in the form of bonggol (not yet shaped tree) and ornament of relief shaped kalpataru tree �anked by lotus �ower on left and right. 2. lotus/padma flower in the area of temple bumiayu found lotus �ower relief, in the form of 3 variations. first, relief of lotus �ower inside the circle has four open �ower petals. second, the relief of the lotus �ower inside the long rectangular panel, the lotus �ower has 5 open �ower petals which are in position above the leaf tendrils. size of high relief are 24 cm, width 40 cm and thickness 20 cm. third, the lotus �ower on a square-shaped panel. the lotus �ower has 10 petals open in position over the leaf tendrils. the �ower of the padma is the designation of a red lotus plant meaning holy �owers in hindu and buddhist teachings. the designation of the padma as a sacred �ower is based on the figure 4. monkey from bumiayu temple 3 plant and �ower characteristics of the padma in such a way as to show the properties of virtue and purity. there are three types of lotus: white lotus (sanskrit: cumuda), yellow lotus (sanskrit: nyilala), and blue lotus (sanskrit: utpala). red lotus plants have roots and tubers grow in the mud underwater; the trunk grows immersed in water; while the wide leaves expanded above the surface of the water. flower buds of young padma will grow from the tubers of plants that are in the mud media at the bottom of the pond or lake. these �ower buds will grow larger and grow ascending to the surface of the water. when the �ower bud has reached its time, the �ower will bloom, burst on the surface of the water. flower padma that bloom will be seen to develop all the petal crown of red �owers that. flower buds are in the middle of the �ower, as a place of pollen and �ower pistil. the lotus grows in east asia, southeast asia, central asia, and south asia. the lotus character that grows in three di�erent media types, namely land (mud), water, and air becomes one of the basic considerations of the establishment of this freshwater plant as a plant capable of representing the three-tiered nature of the universe known in the eastern philosophy of nature, the underworld, the central realm, and the upper realm. in india the lotus is regarded as a sacred plant and therefore the �ower is believed to be a repellent of reinforcements that can give enlightenment and in indonesia the lotus �ower has the same function as in india, especially in the religious context of hinduism and buddhism. the three kinds relief can be seen in figure 1. 3.2.2 thefauna typesdescribed in thetemple panelrelief the types of fauna depicted in the area of temple bumiayu such as lion statues, nandi, turtles, snakes, parrots (ornament makara), and while in the form of reliefs are monkeys, crocodiles and parrots. 1. parrot in the area of temple bumiayu found relief parrots de© 2018 the authors. page 57 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 figure 5. parrot from bumiayu temple 1 figure 6. cow from bumiayu temple 1 figure 7. snake from bumiayu temple 3 scribed on the surface of the panel has a �at �eld rectangular. parrot reliefs were found in temple 1 and 3 bumiayu. parrot reliefs were described in 3 variations. 1). variation 1 the parrot reliefs on the panel have sized 29 cm long, 46 cm wide and 15 cm thick. the depth of sculpture relief is 4-7 cm. the parrot is drawn facing to the right in an expanding manner. the head has a crest, in a bulging, open beak and tail in an uplifted manner with the end of the distillation in the shape of a leaf. birds sit on a bow-shaped stalk. the background of the birds’ �ora is the ornamental �ora. 2) variation 2 variety of ornamental birds the second variation is the panels measuring 17 cm high, 20 cm wide, and 15 cm thick. bird in a position turned to the right, the wings depicted naturalist in a position is expanding, and tail is depicted in leaf stilts. 3) variation 3 variety of ornamental birds depicted on the panels measuring 15 cm, wide: 20 cm and 15 cm thick, the depth of the relief of about 5-8 cm. birds are portrayed forward with open wings. birds perched on the stem of a tree form arc. bird’s eyes bulging, open beaks, feet together in a standing position. the parrot has a solid, stocky and strong-winged postureespecially at the head, neck, and short tail. its beak is large, strong and curved with a pointy tip to open the hard fruits and eat its contents. the wool on the head can expand and close the body hair only one color that is white, gray or black. cockatoos are chatty and screaming. this bird likes to eat grains, fruits and insects. the distribution of cockatoos from australia to the philippines, the sub family has 17 species divided into the genus. some of the uniqueness of the parrot is a bird that is only loyal to one partner and loyal friends. based on the results of research that kakaktua is known parrots can have age of 60 years, monogamy bird that is only mate with one partner, once a year laying, have faithful mating so that if the parrot birds then the bird other parrots came. the parrot is a parrot species. there are 7 types of parrots scattered in indonesia, among others cacatua alba, cacatua galerita, cacatua sanguinea, cacatua go�ni, cacatua moluccensis, probosciger aterrimus, cacatua sulphurea. parrots are the most favored birds because they have a beautifully crafted fuzz or crown feather on their heads. this bird also has a very loud shriek sound. because of its beauty, many parrots are hunted by humans to trade so as to increase the rate of extinction of this type of bird. the yellow-crested cockatoo (cacatua sulphurea) is one of the species of the parrot (cacatua sulphurea) threatened by extinction due to overexploitation of tra�cking and high forest destruction that exacerbates the extinction of parrots. in the area of bumiayu temple found snake relief on panel bumiayu temple 3 and lion stone statue from bumiayu temple 3. relief snake made of terracotta material, size 17 cm, 16 cm thick and 22 cm thick. mouth closed limbs such as eyes, ears, mouth and nose en© 2018 the authors. page 58 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 graved with scratching techniques, cultivating the surface is rough. snake statues are also depicted in a circular position and gripped the front right leg by the statue of the lion. this seems to indicate that the lion has greater strength than the serpent. the snake is defeated by a lion, because its position is held by a lion. 2. snakes in the area of bumiayu temple found snake relief on panel bumiayu temple 3 and lion stone statue from bumiayu temple 3. relief snake made of terracotta material, size 17 cm, 16 cm thick and 22 cm thick. mouth closed limbs such as eyes, ears, mouth and nose engraved with scratching techniques, cultivating the surface is rough. snake statues are also depicted in a circular position and gripped the front right leg by the statue of the lion. this seems to indicate that the lion has greater strength than the serpent. the snake is defeated by a lion, because its position is held by a lion. snakes are a group of animals that have high adaptation levels. snakes can be found throughout the continents and small islands of the earth. snakes are classi�ed scaly reptile class orders: squamata. snakes are distinguished from other reptiles because all snakes have no legs as a means of movement. the high ability of snake adaptation is not always matched by a steady increase in the individual population. all animal species of subordo serpentes or ophidia are part of the squamata order which includes all snake species. snakes are one of the most successful reptiles in the world spread in wet/humid, tropical forests, temperate forests, deserts, grasslands, rice �elds, mountains. snakes are also found in mountains, farmlands, neighborhoods, to the ocean. many species of snakes are live on the ground or crawl under the litter and piles of rocks. while others live aquatic or semi-aquatic in rivers, swamps, lakes and seas. the many species of snakes that live in a habitat depend on the environment in which they live (wiguna, 2009). 3. turtles the turtle statue is depicted in a position under the statue of a lion. in indian mythology the story is known that turtles are animals that are often preyed on by eagles. but with the ingenuity of the tortoise can defeat the garuda in the race run so that the bound garuda no longer treat the tortoise and his descendants. the existence of a turtle under a lion statue shows that the lion has greater strength / ingenuity than the tortoise so that the turtle’s position is placed under the statue of the lion. turtles can live in freshwater (amyda cartilagineae) softshelled or often called labi-labi spread in the indo china region, malacca peninsula, indonesia namely sumatra, kalimantan, java, bali and lombok. animals including the testudinata order, suborder of cryptodira, the trionycidae family, the trionycidae subfamily are generally semi-aquatic, with habitats in calm and shallow waters, slow-moving, shallow, muddy and sandy bottom. these types of labi-labi are often consumed or become pets of the community (sentosa, 2014). another type of tortoise is the tribe’s biuku or tuntong (batagur a�nis) is a type of brackish water turtle members of the tribe geoemydidae. medium-bodied biotic turtles, carapace length 700 mm, nostrils located at the end of a slightly upward muzzle. the jaws are jagged. the skin on the back of the scaly head is small, four claws with a full membrane between the �ngers. his back shield was unpowered, not too high and dropped backwards until it was almost �at. the back is light gray or light brown to greenish black. a male animal in a lust not only has a black back shield; also his head and forelegs. plain abdominal shields are not �ecked or streaked. the turtles inhabit brackish waters and rarely ascend. biuku choose the sand of the river more fresh water. biuku (batagur amyda a�nis) spread to sumatra, malay peninsula, singapore, thailand and burma. 4. crocodile crocodile statue is found in temple 3 bumiayu. crocodile has 6 cm high, 7.5 cm wide and 14 cm thick. crocodile statue depicted in attitude languishing, some body has been lost. his eyes were bulging, mouth closed. his body is depicted in triangular scales carved with gore techniques. the sides on the crocodile’s back are scratchshaped scratches that are u-shaped. the left side foot is crouching and has 3 �ngers. indonesia has 7 (seven) species (species) of crocodiles from all species of crocodiles in the world. various species of crocodile in indonesia include crocodylus porosus, crocodylus siamensis (crocodylus novaeguineae), crocodylus raninus (tomistoma schlegelii), and crocodylus novaeguineae. crocodile is the name of indonesia to name various reptiles from the crocodylidae (tribe) family that being called a crocodile. crocodiles are primeval animals that have undergone only slight changes of evolution since the time of the dinosaurs. it may be said that the present-day crocodile of the former dinosaurs remained relatively unchanged. various species (species) of crocodiles including crocodile species in indonesia have almost the same characteristics. in general, crocodiles have habitat in freshwater waters such as lakes, swamps and rivers, but some are living in brackish water such as estuarine crocodiles. in the estuary of the river is called estuary crocodile (crocodylus porosus). crocodile estuaries also have a very wide dispersion habitat, even the broadest of all other crocodile species. crocodile estuaries can be found starting from the bay of bengal (india, sri lanka and bangladesh) to the fiji islands. indonesia became the most favorite habitat for estuarine crocodiles. the estuarine crocodile morphology character is able to adapt to water salinity, can live from high salinity water such as sea water to fresh water in the upper part of the river. 5. monkey © 2018 the authors. page 59 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 figure 8. lion from bumiayu temple 3 figure 9. lion from bumiayu temple 1 monkey reliefs are found in temple 3 bumiayu, made of terracotta material. the monkeys are depicted in an upright position inside a circle-shaped pane, the nose of a pug with its mouth, the body and legs of the monkey have been broken. long-tailed monkeys or macaca fascicularis are widely preserved by indonesians, and are scattered throughout most of indonesia and southeast asia. the physical characteristics of this monkey can be seen from its long tail, the entire body covered with graycolored fur to blackish brown. monkeys spend most of their time on trees. long-tailed monkeys live in groups, female monkey pregnant for 6 months and generally give birth to one child. long-tailed monkey habitats are tropical rain forests, and are often found near secondary forests adjacent to the inhabitants for ease of getting food. macaca fasicularis usually consume fruits, insects and enjoys exploring, socializing and feeding. macaca fasicularis can live for 31 years. the conservation status of this monkey is not protected. the spread of long-tailed monkeys includes the islands of sumatra, kalimantan, bangka, belitung and the surrounding islands of tambelan, natuna, nias, java, bali, bawean, maratua, lombok, sumba, sumbawa and flores. long-tailed monkeys have varied hair, gray to brownish, and usually to the chest until the stomach is white. the tail length is almost the same as its body length, about 38-64 cm. characteristic of this long-tailed monkey is a cheek rim and a cheek bag that serves as a temporary storage place before chewing. the weight of monkey between 4-8 kg and female rat-average 3 kg. macaca fascicularis is social and lives in a group consisting of many males and many females of 6-58 individuals (kamilah, 2013). beruk (macaca nemestrina) has brown hair that covers the entire body, and in the head there is black or dark brown hair. characteristic of the monkey is to have a short tail like a pig’s tail. posture looks stronger, and in males have long fangs. body length ranges from 46-56 cm. beruk found sumatra and kalimantan spread to india, china, thailand, cambodia, laos, and malaysia. habitat of residence are in lowland and primary forest areas. but it can be found in the forest and near the water source. monkeys and bears include herbivorous animals because 60% consume fruits, and �owers, leaves, seeds, tubers, insects, eggs, and other types of invertebrate animals. 6. beefs beef statues are found in temple 1 bumiayu, made of white stone (limestone). the statue known in indian mythology is the vehicle of lord shiva, another name of the cow is nandi. in the hindu confession, the statue of nandi is usually placed in the ancillary temple located on the north side of the main temple. the cow comes from the bovidae family such as bison, bull, bu�alo (bubalus), african bu�alo (syncherus), and anoa. domestication of cattle began to be done © 2018 the authors. page 60 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 figure 10. parrot from bumiayu temple 3 figure 11. turtle from bumiayu temple 3 about 400 years bc. cows are thought to originate from central asia. then they spread to europe, africa and throughout asia. towards the end of the 19th century, ongole cattle from india were introduced to the island of sumba and since then the island has been used as a pure breeding of pure ongole cattle. broadly speaking, the cattle (bosses) in the world are two, namely (1) zebu (bos indicus) cattle or humped cattle, originating and scattered in the tropics and (2) primus bovine cattle without humps, scattered in sub-tropical regions or known as bos taurus. along with the development of technology until now estimated there are more than 300 beef cattle nation. all domestic cattle come from (bos taurus and bos indicus). the new family includes all types of domestic cattle and the bovidae family. zoological cattle classi�cation is phylum: chordata; clas: mammals; order: artiodactyla; sub order: ruminants; family: bovidae; genus: bos and species: bos taurus and bos indicus (suripto, 2001). until now the cattle are still farmed bumiayu villagers. even some cows are allowed to roam the site and not put in the cage by their owners. in the past many people still keep cows, but since becoming a cultural heritage area, many residents have turned their livelihoods into rubber gardening. 7. lions the statue of the lion from the region temple bumiayu depicted in 3 positions. first, the statue of the lion is depicted standing with a pouncing position, tail up, there are ornaments leaf tendrils under the body. at the bottom of the lion statue is the head of the statue of a turtle. this statue is placed in the corners of the building of temple 1 bumiayu. second, the lion statue is depicted in a sitting posture on a rectangular-shaped mat. the tail up, has a mane under his neck, the left front leg is upright, while the front right leg is lifted up while gripping a snake. the face of the statue looks upward, eyes bulging, mouth open so that the tongue and teeth look. the lion statue of temple 3 bumiayu has an overall height, along with its plaster: 77 cm long, the height of statue: 68.5 cm, width: 50 cm. third, the lion statue is depicted in pairs with elephant and gana statues. the gana statue is above the lion supported by the elephant. lion statue, elephant and gana made of granite material and overall height 60 cm, width 45 cm and thickness 53.5 cm. the lion has a valiant and authoritative physics often associated with its function to alert the public of its greed. the �rst image of a lion is found in a sculpture on the walls of the ancient egyptian pyramids (susanto, 1998). in the hindu people, the lion statue is associated with a symbol of leadership, rulers and powers such as the lion statue being the guardian of the prambanan temple. the lion statue is usually placed on the right/left side of the entrance in a sitting position with a pair of front legs upright supporting the weight, the grinning mouth showing the teeth and fangs, eyes glaring fearfully, the © 2018 the authors. page 61 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 table 1. type of fauna in the region of bumiayu temples no clasis ordo familia genus/specieslocal name 1 reptile chelonia turtle 2 reptile squamata snake 3 reptile crocodilia crocodilidae crocodilus crocodile 4 aves psittacivormes psittacidae pssitacula parrot 5 mammalia carnivora felidae panthera leo lion 6 mammalia artiodactyla bovidae bos cow 7 mammalia primata cercopithecidaemacaca long-tailed monkey hair of his mane decomposing to the nape of his neck and falling beneath his chin. the statue of the lion other than embodied in the form of a statue is also depicted in the form of a relief carved on the outer wall of the temple’s cheek and found in some temples between the apit temple, brahma, prambanan complex and pawon temple, gerabak, central java. lions or panthera leo, is a family of felidae genus panthera is the largest type of cat weighing 150 kg lion and 225 kg male lion. it has a body length of 1.60-1.90 meters (female) and 1.70-2.50 meter (male). characteristics: males have a hair mane on their head. the body is covered in a short, brown coat for both sexes, pale at the bottom, without signs. the back of the ears and a bundle of hair at the end of the tail is dark brown or black. habitat lions live in savanna forests, deserts and mountains in india and africa. zoetmulder said that the lion is a beast that the name not from indonesia, so the term sinha that was interpreted/associated with heroes, warriors and bravery (zoetmulder, 1983). so the lion animal has never lived in indonesia, including in the region temple bumiayu. therefore the existence of the statue of the lion at temple 1 and 3 bumiayu has symbol meaning symbolizing the strong/mighty animal as a hero/warrior who will keep the sacred buildings. all the �gure of the animal in point a to g are described in figure 4 to 11. each �gure described one animal. table 1 explain the clasi�cation of each animal in region bumiayu temple (zoetmulder, 1995). 4. conclusions regions bumiayu temple located in penukal district abab lematang ilir is a lowland area that has a height of less than 100 meters from the sea surface and has rainfall that varies between 98.98 mm to 412.26 mm throughout the year 2013. this area has a soil alluvial, red yellow podzolic, gley association and pale yellowish brownish association. therefore the �ora and fauna in the bumiayu enshrinement area are categorized in the biomes of tropical rainforests ie forests with towering trees with canopies that have layers of tree branches along with the leaves that are formed by the meeting of trees. based on the survey results, it is known that the rubber plantation area and after this location turned into a cultural heritage area, as the rubber plantation felled. the vegetation environment in the temple bumiayu area is covered by several plant species such as rubber (hevea brasiliensis), bamboo (bambusa sp.) shrimp vegetation with melastoma, glichenia linearis, macaranga, vitis and various graminae species of imperata cylindrica and axonophus. there has been a change of vegetation environment due to forest clearing by converting forest land into rubber plantation area (hevea brasiliensis). the other plantation is oil palm (elaeis guineensis), but the main result of the region of temple bumiayu is rubber. even inside the site, until now the ongoing rubber market. rubber market activity brought the area to become dirty, so the local government tried to move the rubber market location. vegetation in the area of temple bumiayu is a vegetation of shrubs and forest vegetation. fertile soil and suitable climate is one of the supporting factors for the development of various types of plants that make this area rich in agricultural products and crops, especially rubber production plants (hevea brasiliensis), besides rubber, other plantations in the form of palm oil (elaeis guineensis ), coconut (cocos nucifera), co�ee (co�ea arabica), areca catechu, and candlenut (aleurites molucceana) besides the plant species that make up the forest vegetation ie wood of rake (aquilaria malaccensis), surian (toona sureni shorea sp.), bayur (pterispermum javanicum), petai (leucaena glauca). in addition there are crops for daily needs such as eggplant (solanum melongena), long beans (vigna sinensis), ketapang (moringa oleifera), durian (durio zibethinus), mangosteen (garcinia mangostana), pare (trichosanthes anguina), eggplant milk (solanum mammosum), cayenne (capsicum frutescens), corn (zea mays), bananas (moses hybrids). vegetation of shrubs is found such as ageratum conyzoides, ageratum conjugatum, piper aduncum, imperata cylindrica, erythrina variegata, lantana camara and others. from the survey results of plant species in this region shows the ecosystem units of this region is mixed dipterocarp forest including in the rain forest biomes are always wet to dry with sub-biomes of dry land rain forest. based on vegetation data in the form of existing plant © 2018 the authors. page 62 of 63 siregar et. al. indonesian journal of environmental management and sustainability, 2 (2018) 54-63 species, the ecosystem unit in this region is dipterocarpacacac rainforest with red yellow ultisol soil. based on the reliefs of temple 1, 3 and 8 bumiayu, there are found �oras such as kalpataru trees and lotus plants. the kalpataru tree is not found in this region, because it is a sacred tree for hindu umt and is found today in india. while lotus plants until now many found in this area as lake lebar is 1 kilometer from the site. fauna such as long-tailed monkeys, parrots, cows, snakes, turtles and crocodiles, only lions are absent because they are not habitat in the area of temple bumiayu. statue of lions and reliefs of kalpataru trees in the temple area of religious function which because the temple building was established for hindu worship. statues of lions are made as guardians of the sacred buildings that are usually placed in front of the entrance to the temple and in front of the gate of the temple. references bosch, f. (1930). verslag van een reis door sumatra. ouheidkundige verslag; 151–152 brandes, j. (1902). ouheden encylopedie van nederlandsch indie. nederlandsch indie budisantoso, t. (2000). analisis candi bumiayu 3 in berita penelitian arkeologi 5. balai arkeologi palembang istanto (2017). ragam hias pohon hayat prambanan. jurnal imajinasi, xi(1); 20–22 kamilah (2013). perilaku grooming macaca fascicularis di taman hutan raya rajolelo bengkulu. jurnal konservasi hayati, 9(2); 1 kartoatmodjo and m. soekarto (1993). temuan prasasti boom baru di sumatera selatan dan masalah taman sri ksetra dari kerajaan sriwjaya. palembang: museum negeri propinsi sumatera selatan “balaputadewa” knaap (1904). rappport van den controleur onderafdeeling lematang ilir van de in de lematang streek tuschen benaket en modong aan getro�en oudheden. notulen bataviaasch genootschaap 41. bijlage. muhajirin (2010). dari pohon hayat sampai gunungan wayang kulit purwa (sebuah fenomena transformasi budaya). jurnal seni rupa uny purwanti, r. (1996). sungai-sungai di sekitar percandiaan bumiayu, kecamatan perwakilan tanah abang, kabupaten muarenim, provinsi sumatera selatan. laporan penelitian arkeologi. palembang: balai arkeologi palembang ratnawati, l. (1989). variasi relief kalpataru pada candi prambanan. ikatan ahli arkeologi indonesia satari, s. (2002). sebuah situs hindu di sumatera selatan; temuan kelompok candi dan arca di bumiayu. jakarta: pusat penelitian dan ecole francaised’extreme-orient schnitger, f. (1937). the archaeology of hindoe sumatra. leiden: ej brill sentosa, a. (2014). habitat dan biologi labi-labi di kabupaten kutai, kalimantan timur. pengembangan teknologi terapan untuk meningkatkan produksi perikanan. seminar nasional perikanan indonesia suripto (2001). relief jenis-jenis fauna dan setting lingkungannya pada pahatan dinding candi borobudur. jurnal manusia dan lingkungan,, viii(1); 43 susanto, r. (1998). beberapa bentuk penjaga candi. berkala arkeologi sangkhakala no. iii/1998-1999. balai arkeologi medan tombrink (1864). hindoe monumenten in de bovenlanden van palembang als bron van geschiedkundieg onderzoek., volume deel xix. bataviaasch genootschap van kunsten en wetenschappen utomo, b. (1993). situs percandiaan tanah abang. laporan penelitian arkeologi. pusat penelitian arkeologi nasional: 4. wiguna, c. (2009). inventarisasi jenis ular di desa keliling benteng ilir kecamatan sungai tabuk, kabupaten banjar. jurnal wahana-bio, i; 34 zoetmulder, p. (1983). kalangwan sastra jawa selayang pandang. terjemahan: dick hartoko. jakarta: jambatan zoetmulder, p. (1995). kamus jawa kuna-indonesia. penerjemah darusuprapto dan suprayitno. jakarta: p.t. gramedia © 2018 the authors. page 63 of 63 introduction experimental section results and discussion the region of bumiayu temples types of flora and fauna described in the region temple bumiayu flora types described on temple panels the fauna types described in the temple panel relief conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper distribution of cadmium (cd) within water around the final waste disposal (fwd) of sukawinatan palembang deni julius1*, suheryanto2, laila hanum3, 1department of environmental management, school of graduate program, sriwijaya university, jalan padang selasa, palembang, indonesia 2department of chemistry, faculty of mathematics and science, sriwijaya university, jalan palembang prabumulih km 32, indralaya, indonesia 3department of biology, faculty of mathematics and science, sriwijaya university, jalan palembang prabumulih km 32, indralaya, indonesia *corresponding author e-mail: accountname@email.com abstract research has been conducted on the bioacumulation of cadmium in the leachate, sediment, sepat fish and watercress within water around the final waste disposal (fwd) of sukawinatan palembang used atomic absorption spectrophotometric (aas) analysis.this research determined the distribution of cadmium that was contained in water ecosystem within water around the final solid waste disposal (fwd) of sukawinatan, as well as bioconcentration factor (bcf) of the biotic compartement to the abiotic compartement. the way was done by wetdestruction sample. the resultant destruction solution was analyzed at a wavelength of 228.8 nm. the results showed that the concentration of cadmium in leachate inlet 0.0099 mg/l until the sedapat river 0.0010 mg/l, sediment inlet 0.0427 mg/kg until sedapat river sediment 0.0051 mg/kg, sepat fish reservoir 0.0099 mg/kg and sepat fish sedapat river 0.0096 mg/kg along watercress reservoir 0.0042 mg/kg is over sedapar river 0.0027 mg/kg. so, the distribution of cadmium for water and sediment compartment decreased from leachate inlet to sedapat river. the value of cadmium consentration in leachate is still below the threshold conformable in regulation of environment and forestry ministers no.59 of 2016 is 0.1 mg/l. distribution on the fish and watercress compartment also descreased to the sedapat river. consentration value on the fish and watercress also still below the quality standard in this sni 7378;2009 for fish 0.1 mg/kg and watercress 0.2 mg/kg, while the value of bcf fish and bcf watercress ¡100 is still in low category. keywords distribution, cadmium, bioconsentration factor received: 29 june 2018, accepted: 20 august 2018 https://doi.org/10.26554/ijems.2018.3.2.84-87 1. introduction one landfill in the city of palembang is located on an area sukawinatan sukajaya sukarame subdistrict in palembang, south sumatra. every day, the amount of waste that goes to landfill sukawinatan are ± 500-600 tonnes/day. waste composition that goes into landfill sukawinatan are food scraps, leaves and paper which is an organic material. then the solid waste and b3 which potentially contain cadmium contamination i.e. batteries, thermometers, fluorescent lights, steroform are not managed properly. according to warsinah (2015), pb heavy metal levels around the landfill leachate sukawinatan as below 0.09 mg/l, the river far as 0.025 mg/l, sediment 9.10 mg/kg, plant 1,43 mg/kg and fish 0, 94 mg/kg. based on these data, the decomposition of waste going into landfill affects the amount and type of contamination. garbage decomposition process produces two major factions, namely organic and inorganic fractions. the inorganic fraction contains a variety of minerals, including heavy metals. heavy metals was contained in the garbage decomposes and dissolves along with the formation of leachate. all results of this decomposition to form a unity with the ground. the role of land to the transport and removal of contaminants is very large. the transport process is diverse, such as the drainage, seepage, and melting. heavy metal migration more quickly when the environment around the landfill is an area of water (palar, 2008). 2. experimental section 2.1 analysis of the metal content of cadmium (cd) in water samples dilute the samples of leachate with water adjus the ph with hno3 to ph¡2 taken as many as 100 ml homogenized by means of a knot, add back in 5 ml of hno3, then heat the test sample until almost dried up, demineralized water was added back as much as 50 ml, then pour into the 100 ml volumetric flask using filter https://doi.org/10.26554/ijems.2018.3.2.84-87 julius et. al. indonesian journal of environmental management and sustainability, 3 (2018) 84-87 paper, dilute up to 100 ml with demineralized water, after that the samples are ready to be tested. 2.2 analysis of metal content cadmium (cd) in sediments, watercress and sepat fish sediment sample is cleaned of impurities, then drain and puree samples. likewise with watercress clean and cuts. sepat fish is measured in length and meat. each sample was dried in the oven for 24 hours at 60°c, and then mashed it. fine samples were drawn 2 grams and then inserted into a pumpkin, add a mixture of hno3 and hcl in the ratio (3:1) 10 ml hereinafter destruction to dissolve the sample, and then the flask removed from the heater and added h2o2 as much as 1 drop and chill. after a solution was cold, it was filtered with filter paper, andit was diluted to 50 ml with demineralized water and analysis with aas. 2.3 data analysis data analysis includes an analysis of the concentration of cadmium metal in the compartment of water, sediment, plants and fish based measurement using aas instruments. the next stage of analyzing the data descriptively compare measurement data with quality standards in accordance with regulation of environment and forestry ministers no.59 of 2016 about garbage leachate water quality standards, and sni 7387; 2009 the maximum limit of heavy metal contamination in food. 2.4 analysis bioconcentration factor (bcf) watercress and sepatfish samples calculated value of bioconcentration factor (bcf), bioconcentration factor is a parameter used to evaluate the potential of the species in the accumulating compound that is generally used for heavy metals. bioconcentration factors for biota (fish) consists of the biota and water bcf (bcfo-w), whereas for the plant consists of bcf plant to water (bcfo-w) and bcf plants against sediment (bcfos). bioaccumulation factor describes the level of metal content in the samples. bioconcentration factor formula: bcf(o − w) = corg cwater (1) bcf(o − s) = corg csed (2) note: bcf = bioconcentration factor c org = cd concentration in organisms c water = concentration of cd in water c sed = concentration of cd in sediment 3. results and discussion 3.1 cadmium concentration on compartment water and sediments concentrations of cadmium found in the water compartment was analyzed in some sampling area, covers an area inlet, leachate pool, processing pool, outlet and sedapat river show in the table 1. cadmium concentration research results showed a downward trend, both compartments of water and sediment. the highest concentration value at an leachate inlet 0.0099 mg/l and the lowest at river 0.0010 mg/l. the value of cadmium consentration in leachate is still below the threshold conformable inregulation of environment and forestry ministers no.59 of 2016 is 0.1 mg/l. the concentration of dissolved cadmium can be influenced by the distance from the source of leachate. closer distance to the source of leachate will have a greater cd levels than longer distances. the cause of this situation is the concentration of leachate is more concentrated than at large distances. so the more concentrated the leachate consentration, the level of metal cd concentration automatically is also large. likewise with cadmium concentrations of sediment showed a trend of decreasing when the distance is further away from the sources of pollution. the concentration of cadmium contained in the sediments inlet 0.0427 mg/kg and the smallest on the river far as 0.0051 mg/kg. 3.2 cadmium concentration in watercress (ipomoea aqutica) and sepat fish (trichogaster trichopterus pallas) the concentration of cadmium metal in water kangkuang was listed in table 2. the cd accumulates in the pool 4 was 0.0042 table 1. the concentration of cadmium in abiotic compartment location concentration of cadmium in abiotic compartment water water quality standard sediment sediment quality standart (mg/l) (mg/l) (mg/kg) (mg/kg) 1. inlet 0.0099 0.1 0.0427 anzecc 2. leachate pool 0.0096 0.1 isqg-low 3. pool 1 0.0075 0.1 0.0314 -1.5 4. pool 2 0.007 0.1 0.0306 5. pool 3 0.0069 0.1 0.0222 6. pool 4 0.0038 0.1 0.0143 sepa year of 2000 7. outlet 0.0035 0.1 0.0075 (≤ 0.8 -kelas 1-very low conc.) 8. sedapat river 0.001 0.1 0.0051 *regulation of environment and forestry ministers no.59 of 2016 © 2018 the authors. page 85 of 87 julius et. al. indonesian journal of environmental management and sustainability, 3 (2018) 84-87 table 2. concentrations of cadmium in biotic compartment locations concentration of cadmium in biotic compartment (mg/kg) sepat fish *quality standards watercress *quality standards 1. pool 4 0.0099 0.1 0.0042 0.2 2. sedapatriver 0.0096 0.1 0.0027 0.2 *sni 7378;2009 mg/kg whereas in rivers far as 0.0027 mg/kg. this value is still below the threshold contained in sni 7383; 2009 of 0.2 mg/kg. one factor, that accumulation of heavy metals in aquatic organisms such as watercress,was temperature. in the marine environment, the chemical reaction is very sensitive to temperature changes, besides the temperature also greatly affects the quantity of heavy metals are absorbed by plants. rising temperatures affect intake and expenditure levels of heavy metals by plants because of rising temperatures increase the rate of metabolism in aquatic plants (manahan, 2000). the concentration of cadmium in the flesh of sepat fish in the pond was 0.0099 mg/kg and rivers far as 0.0096 mg/kg. according to sni 7378; 2009 the concentration of cadmium in fish value is still below the quality standard is 0.1 mg/kg. under natural exposure conditions, prediction of toxic effects based on environmental or tissues concentrations remains difficult while many studies have examined the relationship between metal exposure, accumulation and toxicity under laboratory conditions (ali et al., 2013). 3.3 bioconcentration factor (bcf) watercress and sepat fish from the calculations, the bioconcentration fish ponds and the river far as 7.7000 1.2392. as for the pool water to water spinach (bcfo-w) on an 0.0438 and 2.7000 river, the plant against sediment bioconcentration factor (bcfo-s) 0.1892 and 0.5294 on river. bioconcentration factor is higher than the fish with watercress caused by the high mobility of fish in the water, so the fish bioconcentration against higher water. while water is just creeping watercress in pool, so the interaction watercress limited only around the edge of the pond or river. likewise watercress to sediment only interaction around the edge of the pond and river. so that the accumulation is increased through gills that interact with water and digestive organs untilfish tissue. according to van esch (amriani and hadiyarto, 2011), when the value of bcf less than 100 in the category of low accumulative value 100-1000 categories accumulative moderate and above 1000 high accumulative. overall bioconcentration factor fish and watercress to water in ponds and rivers as much as ¡100 classified as low accumulative. 3.4 distribution metal cadmium in different compartments cadmium distribution of inlet flow pattern, the leachate pond, settling ponds uotle up towards the river wherever the water and sediment compartment tends to decrease, as well as in plants and organisms tends to decrease as seen in figure 1. the highest distribution on the sediment compartment, the high metal concentrations in sediment deposition resulting from the effects of the chemical, oxidation-reduction events and acidity, adsorption phenomena of physics effects and biological effects characterized by bacterial activity. metal distribution in each compartment based on the distance from the inlet to the pond to the extent to compartments river water and sediment, the concentration of cadmium decreased. for plants and fish in the river, metal concentrations are lower than the concentration of metal in the settling ponds. the presence of cadmium in plants and fish indicate the accumulation in the compartment. in particular, bioaccumulation of cd, arsenic, manganese, figure 1. graph distribution of cadmium in all of compartments © 2018 the authors. page 86 of 87 julius et. al. indonesian journal of environmental management and sustainability, 3 (2018) 84-87 mercury, and lead in the food chain is a cause of concern because these metals have deleterious effects on human health furthermore, fish and seafood is one of the main links between heavy metal present in the environment and human exposure (fraser et al., 2012). 4. conclusions levels of cadmium in water is still below the environmental quality standard set out in the regulation of the minister of environment and forests no. 59 of 2016. bioconcentration factor of fish to water (bcfo-w) in the pool and the river, as well as bioconcentration watercress for metals in water (bcfo-w) and sediment (bcf0-s) in the pond and the river wherever ¡100 classified as low accumulative. distribution of cadmium metal for water and sediment compartment increasingly distant sources of leachate is up to the river inlet concentration decreases. in fish and watercress metal distribution in the settling ponds is higher than wherever river. references ali, a., k. said, and i. messaoudi (2013). cadmium: bioaccumulation, histopathology and detoxifying mechanisms in fish. american journal of research communication, 1(4); 60–79 amriani, b., hendrarto and a. hadiyarto (2011). bioakumulasi logam berat timbal (pb) dan kadmium (cd) pada kerang darah (anadara granosa l.) dan kerang bakau (polymesoda bengalensis l.) di perairan teluk kendari. jurnal ilmu lingkungan, 9(2); 45–50 fraser, m., c. surette, and c. vaillancourt (2012). fish and seafood availability in markets in the baie des chaleurs region,new brunswick. canada: a baseline study heavy metal contamination.environ sci pollut manahan, s. (2000). environmental chemistry.seventh edition. lewis publisher. crc press library of congress cataloging palar, h. (2008). pencemaran dan toksikologi logam berat. pt rineka cipta, jakarta warsinah (2015). kajian cemaran logam berattimbal (pb) pada kompartemen perairan di sekitar tempat pembuangan akhir (tpa) sukawinatan palembang. master’s thesis, universitas sriwijaya,palembang © 2018 the authors. page 87 of 87 introduction experimental section analysis of the metal content of cadmium (cd) in water samples analysis of metal content cadmium (cd) in sediments, watercress and sepat fish data analysis analysis bioconcentration factor (bcf) results and discussion cadmium concentration on compartment water and sediments cadmium concentration in watercress (ipomoea aqutica) and sepat fish (trichogaster trichopterus pallas) bioconcentration factor (bcf) watercress and sepat fish distribution metal cadmium in different compartments conclusions indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article doi: 10.26554/ijems.2017.1.1.15-1815 received: 2 september 2017 accepted: 30 october 2017 *corresponding author email: jehanfarhan.jl@gmail.com analysis of blasting effect to the environment around blasting areas of pt. semen baturaja persero, tbk. jihan f.lubis1 , taufik toha1, ngudiantoro2 1 mining engineering department, faculty of engineering, sriwijaya university, palembang 30319, 2 mathematics department, faculty of mathematics and natural science, sriwijaya university, palembang 30319 abstract pt. semen baturaja persero, tbk is one of the companies engaged in the production of cement that takes raw materials through limestone mining process located in baturaja city, oku regency, south sumatera province. limestone mining activities use blasting activity that produces blasting effects and flyrock. measurements of vibration and flyrock frequencies obtained a maximum value for vibration of 4.66 mm/s and predicted farthest distance of flyrock above 170 m when powder factor exceeds 0.1 kg/m3. the results of the data show that the level of emission has exceeded the standard limits for second class buildings (3 mm/s) based on (sni) 7571: 2010. blasting just 175-300 m from the nearest settlement and already exceed the save distance for equipment 300 m and 500 m for human activity based on usbm (united states bureau of mines). to reduce the vibration level, the maximum number of mass per delay is 43 kg/delay with ppv parameter 3 mm/s at 170 m distance. actual factor powder should not exceed 0.1 kg/m3 to minimize flyovers in safe zones not exceeding 150 m. keywords: blasting, flyrock, vibration, powder factor 1. introduction blasting is one of the rock excavation methods used to destroy hard materials of large size into smaller materials that can be easily transferred by heavy equipment [1]. mining activities have been recorded using millions of kilograms of explosives annually and most blasting activities are carried out in open pit operations [2]. the blasting activity will have some direct effects such as flying rock, vibration, air blast and noise. this explosive effect will cause various impacts to the environment around the blasting area, including slope instability and damage to building structures. this can occur when the high blasting frequency is accompanied by high vibration and air blast [3]. several studies have been done in analyzing and attempting to reduce the explosive effects as t.s bajpayee has conducted studies on the prevention of flyrock accident in open pit mining [4]. h.s venkatesh has analyzed the reduction of the blasting vibration level by making a trench on the open pit [5]. in this research will be analyzed the impact of explosive effect especially on vibration and flyrock which resulted from blasting activity in quarry mining of limestone pt. semen baturaja persero, tbk. this analysis needs to be done due to blasting activities that are very close to the settlement (170-300 m) which causes the level of detonation effect to be felt by the society. it is expected that through this research, can be a consideration of the company in carrying out blasting activities that pay more attention to environmental and community conditions. 2. experimental section 2.1. research sites the location of the research was conducted in quarry of limestone pt. semen baturaja persero, tbk. vibration data retrieval is done in smp 7 pusar area, the location selection is based on the consideration of the distance of the nearest building (the building of the residents) with the location of the blasting [6]. the distance of the blasting location to the nearest settlement is 180 meters while the furthest is 297 meters as seen in figure 1. 2.2. tools and materials flyrock data is taken daily by visual recording using video camera as seen in figure 2. vibration and airblast data was taken with daily frequency using vibration and noise gauge called blastmate iii [7]. 2.3. flow chart of research figure 3 described the research stages. studies data retrieval 1. operational blasting stages. 2. flyrock, vibration and airblast levels. 3. video blasting and blasting documentation. 4. blasting geometry data processing blasting effect analysis and reduction of blasting effect conclusion figure 1. research location quarry limestone at baturaja east oku lubis et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 15-18 doi: 10.26554/ijems.2017.1.1.15-1816 3. results and discussion 3.1.vibration blastmate iii will record vibrations and noise on a regular basis with a minimum limit of 0 mm/s, with a recording range of 260 m [8]. the results of recording data of april to october are summarized in the maximum limit of 2 mm/s 5 mm/s. the result of maximum vibration and limitation is showed in figure 4. maximum vibration reached was 4.66 mm/s on september 5th. the standard ground vibration threshold value referred to sni 7570: 2100 is maximum 3 mm/s for category 2 building [9]. the result of the measurement data below shows the potential vibration level to cause damage to building if the frequency of vibration occurrence is high [10]. based on the percentage data accumulated from vibrations above 1 mm/s to 5 mm/s, the percentage of the vibration level of the blast measurement results can be seen in figure 5. 3.2. flyrock the flyrock data was taken from actual blasting activity based on the actual and planning blasting design. table 1 shows the database of rock throw rates from blasting that has been implemented. based on the number of data retrievals for 14 days, the percentage of flyrock emerged that exceeded the limitation of planning ranged from 42.86% with the farthest throw as far as 188 m. this is certainly very dangerous considering the settlement is very close to the blasting activities [11]. 3.3. level of damage caused by the blasting effect the resulting blast effect has an effect on the community activity around the mine, especially to the structure of the community building. the type of housing located around the mine site of pt. semen baturaja especially in talang jawa and pusar area is housing with foundation, including foundation with wood, masonry couple, some building wall using pillar foundation of ordinary mortar, but also found that do not use foundation pole, and the floor is given mortar. based on sni 7571: 2010, the building is classified as a 2nd class building [12]. residents around the mine claim that their homes are cracked as a result of blasting activities undertaken by ptsb. type of damage to houses, namely the cracks in the wall which is the arrangement of bricks and walls that have been using the pillar foundation mortar cement, can be seen in the picture. the community also once commented on the existence of flying stones that hit the roof of their house. one of the damage situation of resident around blasting area is shown in figure 6. 3.4. efforts to minimize blasting effects 3.4.1.minimize vibration with scaled distance limitation vibration measurement results are incorporated into log charts for prediction of vibration limitation based on usbm (united states of bureau of mines) is shown in figure 7. with a ppv limitation of 3 mm/s as a security consideration, the scale distance result was 25 and the maximum explosive per delay that can be used is 43 kg / delay at a distance of 170 m. with explosive capacity of 16 kg/holes at a depth of 6 m holes, the number of explosive burst per holes shall be 3 holes/delay only. in the 9 m depth explosion hole with a capacity of 20 kg/hole, then the blasting per delay can only be done as much as 2 holes/ delay. it is expected that with this limitation the explosive effect of vibration can be reduced. studies data retrieval 1. operational blasting stages. 2. flyrock, vibration and airblast levels. 3. video blasting and blasting documentation. 4. blasting geometry data processing blasting effect analysis and reduction of blasting effect conclusion figure 2. vibration and noise gauge (blastmate iii) figure 3. flow chart of research table 1. flyrock data from actual blasting date hole quantity explosive powder factor pf plan flyrok plan real 4.9.17 151 1200 0.09 0.1 151 136 5.9.17 130 1750 0.11 0.1 151 164 6.9.17 102 1000 0.11 0.1 151 157 7.9.17 105 1300 0.14 0.1 151 188 11.9.17 104 725 0.08 0.1 151 127 12.9.17 96 1225 0.11 0.1 151 164 13.9.17 92 800 0.09 0.1 151 145 14.9.17 90 925 0.08 0.1 151 135 16.9.17 102 900 0.1 0.1 151 149 23-sep 78 975 0.07 0.1 151 121 27-sep 150 2000 0.11 0.1 151 156 28-sep 83 925 0.08 0.1 151 127 2-oct 75 1026 0.12 0.1 151 171 4-oct 70 875 0.1 0.1 151 147 lubis et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 15-18 doi: 10.26554/ijems.2017.1.1.15-1817 3.4.2. reducing flyrock with limitation powder factor the condition of the blasting activities, which is only 170-300 m apart with the settlement, requires the blasting to be carried out thoroughly. using the svedefo equation (probability hit at 1 in 10 million) the save distance can be calculate using formula: 0.6735( )l dk= (1) where: l: distance from blast (m) d: holes diameter (mm) k: powder factor (kg/m3) considering the 150 m as throw rock save distance and holes diameter 89 mm, the maximum powder factor that can be used is 0.1 kg/m3. field conditions that cause variable changes in the figure 4. maximum vibration and limitation figure 5. vibration percentage table 2. summarizing data showing rate of flyrock blasting exceed 150 m d at e h ol es q ua nt ity e xp lo si ve burden spacing hole depth pf a ct ua l pf p la n flyrok detail information pl an re al pl an re al pl an re al pl an re al 5. 9. 17 13 0 17 50 3 3 5 4. 5 9 8. 8 0. 11 0. 1 15 1 16 4 spacing, and the burden shrink, holes depth is reduced 6. 9. 17 10 2 10 00 3 2. 5 5 4. 5 9 8. 2 0. 11 0. 07 15 1 15 7 spacing, and the burden shrink, holes depth is reduced 7. 9. 17 10 5 13 00 3 2. 2 5 4. 5 9 9 0. 14 0. 09 15 1 18 8 spacing, and the burden shrink 12 .9 .1 7 96 12 25 3 2. 5 5 5 9 9 0. 11 0. 09 15 1 16 4 spacing, and the burden shrink 27 -s ep 15 0 20 00 3 2. 55 5 5. 5 9 9 0. 11 0. 1 15 1 15 6 spacing, and the burden shrink 2o ct 75 10 26 3 2. 8 5 4. 5 9 9 0. 12 0. 1 15 1 17 1 spacing, and the burden shrink figure 6. the visual damage of the resident building around blast area. lubis et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 15-18 doi: 10.26554/ijems.2017.1.1.15-1818 burden, spaces, depth of the holes and stemming length caused powder factor number changes from the expected plan [5]. from field observations the deviation rate of actual geometry and plans reaches 74%. table 2 showed summarizing data that recorded high flyrock blasting. from 14 blasting, there were 6 blasting or 42.86% which produced a powder factor exceeding 0.1 kg/m3. maximum powder factor produced is 0.14 kg/m3 with flyrock distance of 188 m. high powder factor result due to the occurrence of deviation in blast geometry including spacing, burden, as well as changes in the depth of the hole between planning and actual implementation. in order to maintain powder factor at the limit of 0.1 kg/m3 the company should perform routine checks against actual blasting geometry parameters to avoid deviation from blast plan [5]. 4. conclussion the measurement result of vibration and flyrock level of explosion activity in quarry of limestone shows tendency of negative impact to society environment especially to damage of building structure. the blasting distance close to the community settlements will further magnify the negative effects of the blasting effect. to reduce the level of vibration, the company may consider reducing the number of bursting holes simultaneously into 3 holes/delay for 6m depth and 2 holes delay for holes depth of 9m for ppv result 3 mm/s in 170m distance. companies may also consider the use of longer in holes delay or electronic detonators so that delay time can be made into single holes firing. to minimize the impact of flyrock, the company must ensure the actual powder factor is 0.1 kg/m3. the actual blasting geometry deviation can be avoided by performing monitoring and checking during blast operations. references [1] carlos, l.j. and balkema, a.a. drilling and blasting of rocks. rotterdam, pp 98-105. 1995. [2] wesley, l.b. the fundamental of blast design. in workshop of the golden west chapter of the international society of explosive engineers. pp 1-5. 1999. [3] konya, j. rock blasting and overbreak control, national technical information service springfield. virginia. pp 3-6. 1999. [4] verakis and lobb. 2003. an analysis and prevention of flyrock accidents in surface blasting operations. iea coal research, pp 12-18. [5] zilong, z. 2004. safety evaluation of blasting flyrock risk with fta method, chinese journal of rock mechanics and engineering. 13. pp 23-28. [6] rehak, t., bajpayee, t., mowrey, g., and ingram, d. flyrock issues in blasting, in: proceedings of the annual conference on explosives and blasting technique. isee. pp 165–176. 2001. [7] venkatesh, h.s. reduction of blast induced ground vibrations with open trenches in surface mines. in; the 12th international conference of international association for computer methods and advances in geomechanics (iacmag). pp 5-8. 2008. [8] kahriman. a. 2002. analysis of ground vibrations caused by bench blasting at can open-pit lignite mine in turkey. environmental geology journal, 41. pp 653-66. [9] simon. t. explosive engineer manual hand book. ael mining service south africa. pp 20-50. 2011. [10] eltschlager, k., clarck, d., sthepens, w., best, d. blaster training module. office of technology transfer. orica mining service. pp 56-60. 2008. [11] eltschlager, k., clarck, d., sthepens, w., best, d. orica mining blasting manual guidance, blaster training module, office of technology transfer. orica mining service. pp 18-25. 2008. [12] sundoyo. 2015. kajian ground vibration dari kegiatan blasting dekat kawasan pemukiman untuk mencapai kondisi aman di penambangan batubara. jurnal geologi pertambangan.1. pp 1-8. figure 7. ppv limitation graphic log (usbm) [8] title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper tofu wastewater (tww) treatment and hydrogen (h2) production by using a microbial electrolysis cell (mec) system ibdal satar1*, muhammad mar’ie sirajuddin1, adi permadi2, sukma latifatunnajib1 1department of food technology, faculty of industrial technology, universitas ahmad dahlan, bantul, yogyakarta, 55191, indonesia 2department of chemical engineering, faculty of industrial technology, universitas ahmad dahlan, bantul, yogyakarta, 55191, indonesia *corresponding author e-mail: ibdal@tp.uad.ac.id abstract high organic pollutant in tofu wastewater (tww) raises a negative impact on environmental sustainability and health. therefore, the tww must be treated before it is discharged into the environment. microbial electrolysis cell (mec) is one of the green technologies that can be used to treat wastewater and generate hydrogen as well. this work tries to investigate the performance of mec based on the decrement of organic pollutants in tww. some important parameters of organic pollutants in tww such as chemical oxygen demand (cod), biological oxygen demand (bod), total suspended solids (tss), total dissolved solids (tds), total solid (ts), and ph were evaluated before and after mec operation. the results showed that the cod and bod levels decreased around 56% and 35% while ph increased from 7.90 to 7.16. additionally, the tss, tds, and ts decreased by around 35.0%, 45.5%, and 33.2%. in addition, the optimum hydrogen yield (yh2) and hydrogen production rate (qh2) were obtained at 114 ± 0.1 ml h2/g cod 360 ± 20 ml h2/l/d. overall, the mec system could be used to reduce the level of organic pollutants in tww and generated h2 at the same time. keywords tww, organic pollutants, ph, cod, mec received: 14 november 2022, accepted: 21 february 2023 https://doi.org/10.26554/ijems.2023.7.1.13-19 1. introduction nowadays, environmental sustainability become the main problem that has to solve immediately. there are two environmental issues namely excess of pollutant gases (i.e., co2, co, sox, and nox) in the atmosphere and high amount of wastewater in the environment (manisalidis et al., 2020; igwe et al., 2017). excess gases and high amounts of wastewater are caused by human activities, population and economic growth (lin et al., 2022). it is well known that the use of fossil fuels in industry activities and vehicles increases air pollution over time (lelieveld et al., 2019). in indonesia (represented by jakarta city), according to the air quality life index (aqli) data that the quality of air in indonesia since 2016 is getting worst (greenstone and fan, 2019; istiqomah and marleni, 2020). in fact, air quality index (aqi) in indonesia is ranked 17th worst from 118 countries in the world for the period of 2021. whereas, approximately 70% of wastewater is generated by households and the rest is produced by other sectors (industries, public facilities, office buildings, etc) (igwe et al., 2017; wulan et al., 2022). as presented above, pollutant gasses and wastewater are two main issues currently focused on by researchers. the number of pollutant gasses can be eliminated by replacing fossil fuel with alternative fuel (i.e., h2) (cloete et al., 2022). in addition, the wastewater issue can be solved by performing chemical, physical, and/or biological approaches (ye and li, 2023; gautam et al., 2022). based on these environmental contexts, the authors suggest choosing the biological method to solve both gasses and wastewater issues. there are two biological methods such as fermentation and microbial electrosynthesis technologies (mets) which generally can be applied to treat wastewater and to generate biogas and/or biohydrogen and electricity (son et al., 2021). among these biological approaches, the mets are more interesting compared to the fermentation due to the mets have good efficiency and generate biogas. one of the mets technologies is microbial electrolysis cells (mec). principally, mec consists of two parts which are the anode and cathode side. the anode side converts the organic substrate to volatile fatty acids (vfas) and electrons (e−) (see equation 1), while the cathode side generates hydrogen (h2) from protons (h +) and electrons (see equation 2). due to the hydrogen production being unspontaneous reactions so the additional energy must be https://doi.org/10.26554/ijems.2023.7.1.13-19 satar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 13-19 supplied into the mec system. generally, the amount of additional energy in the mec systems is required in the range of 0.20 0.80 v (call and logan, 2008). anode: organic substrate ch3coo − + 4h2o → 2hco3− + 9h+ cathode: 8h+ + 8e− → 4h2 overall: ch3coo − + 4h2o → 2hco3− + h+ + 4h2 theoretically, the performance of mec depends on some parameters such as anode and cathode performance, type and characteristics of substrates, and amount of additional energy input into the system (apostolopoulos et al., 2021). the substrate with a high simple organic acid, rich nutrient, and neutral ph are very appropriate for generating h2. in general, the additional energy at the optimum condition is obtained at approximately 0.80 v (meshram and jadhav, 2017). this work tries to investigate the performance of f mec system based on the tww quality and hydrogen production when using tww as substrate. some parameters such as the change of ph, cod, bod, tss, h2 yield, and h2 production rate are evaluated. 2. experimental section 2.1 materials materials such as acrylic blocks and cation exchange membrane (cem, cmi 7000s) were obtained from fuel cell institute laboratory (fcil) university kebangsaan malaysia (ukm). whereas, all chemicals were purchased from online shops. some chemicals needed in this work were hydrochloric acid (hcl, analytical grade), sodium acetate (ch3coo-na, 99%), potassium chloride (kcl, analytical grade), ammonium chloride (nh4cl, analytical grade), potassium dihydrogen phosphate (kh2po4, analytical grade) and di-potassium hydrogen phosphate (k2hpo4, analytical grade), ethanol (c2h5oh, 99.5%) and deionized water (dw). the spectrophotometer (thermo-scientific) was used to determine the chemical oxygen demand (cod). the ph tester (h198103, hanna instruments) was used to measure the initial and final ph of tww. the power supply (yihua 1502 dd, dc power supply) was used to supply the additional voltage to the mec system. the scanning electron microscope and electron dispersive x-ray (sem-edx, jeol jsm 5800) was used to characterize the electrode surfaces before and after the mec system run. 2.2 methods 2.2.1 tofu wastewater (tww) preparation and identification a total of 10 liters of tww sample was collected from the tofu home industry nearby imogiri barat. some physicochemical parameters such as ph, chemical oxygen demand (cod), biological oxygen demand (bod) and total suspended solid (tss), total dissolved solids (tds), and total solid (ts) were measured by using apha, winkler, and spectroscopy methods, respectively. the characterizations of fresh tww were presented in table 1. initially, the table 1. characteristic of tww sample parameters average values unit ph 7.90 tds 4546.67 mg/l ts 7920.00 mg/l tss 1903.33 mg/l bod 1400.10 mg/l cod 1066.67 mg/l tww sample was filtered by using a filter cloth to separate the solution and active sludge before it was used in the mec system. then, a filtered solution of tww was kept and used as a substrate for further work. meanwhile, the active sludge of tww was used as a mixed-culture of electroactive bacteria (eab) source in the anode before the mec system was operated. it was well known that the eab must previously be attached and enriched at the anode to enhance the system performance (satar et al., 2021). 2.2.2 preparation of electrodes the preparation of the electrode was addressed to remove the physical impurities on the material surface. the electrode preparation was performed in acid and alkali solutions as described by satar et al. (2021). the electrodes (both anode and cathode) were fabricated from the graphite foam (gf) materials with a configuration of 2.5 cm × 2.5 cm (figure 1). before it was used in the mec system, the electrodes were immersed in the 250 ml hcl (1 m) for 1 hour and washed using deionized water (dw) three times. then, the electrodes were immersed in 250 ml koh (1 m) for 1 hour and washed using dw three times. lastly, the electrode materials were dried in a vacuum oven at 80 oc overnight (satar et al., 2018). figure 1. graphite foam electrodes; anode (left) and cathode (right) materials © 2023 the authors. page 14 of 19 satar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 13-19 2.2.3 dual chamber mec set-up and operation the mec system was designed in the dual chamber types which were fabricated from acrylic block materials. the mec system was divided into the anode and cathode chambers with an active volume of 50 ml, respectively (satar et al., 2020a). both anode and cathode chambers were separated by cem (cmi, 7000s) to prevent a short circuit in the system. the anode and cathode materials were installed with the iron sheet to facilitate the current transfer from a power supply to the system. the schematic and photograph of the mec system were presented in figure 2. figure 2. the design of the mec system; (a) schematic and (b) photograph of dual chamber mec system the mec system was operated at room temperature and fully maintained in anaerobic condition to avoid contamination on eab at the anode and hydrogen gas (h2) release from the cathode (bora et al., 2022). before the mec was operated, the anode was initially enriched with eab using active sludge of tww while the cathode was without chemical catalysts. during the enrichment process, the 1.0 g/l ch3coona solution was used as substrate at the anode while 1 m kcl as anolyte at the cathode. a direct current power supply (yihua 1502 dd) was needed to supply 1.0 v of additional energy into the system because hydrogen production is an unspontaneous reaction. an external resistor (r = 1.0 ohm) was installed at the mec system to convert a voltage (v) from the power supply to current (i). once the h2 gas was produced from the system, the ch3coona substrate in the anode was replaced with tww solution. the operation of the mec system was stopped when the h2 was stably produced in three consecutive runs. 2.2.4 gas analysis and calculation the generated h2 gas was collected using a 25 ml syringe for three consecutive cycles. the amount of generated h2 was calculated based on the purity of h2 production by using dual chamber mec (69–77%). the nh2 is a mole of h2 that is calculated based on the ideal gas formula at standard conditions (equation 1). the mh2 is the molecular mass of h2 (2 g/mol). the cod removal (∆cod) is calculated based on the total cod value at the beginning (cod0) minus the cod value at the final (codt). the h2 yield (yh2) and h2 production rate (qh2) were calculated by table 2. summary of tww characterization at the final of mec run parameters average values standard (peraturan daerah diy, 2016) ph* 7.16 ± 0.1 6.0 – 9.0 tds 2476.67 mg/l ts 5293.33 mg/l tss 1236.67 mg/l 200 mg/l bod 490.04 mg/l 150 mg/l cod 469.33 mg/l 300 mg/l note: * = the ph of tww after the mec system run using equation 2 and equation 3, respectively (satar et al., 2020b). nh2 = pv rt = vh2 22.4l (1) yh2 = nh2 × mh2 vl × ∆cod × 100% (2) qh2 = vh2 va × t (3) figure 3. images of surface morphologies of electrode and element compositions: (a) electrode image, (b) edx spectra data before the mec system run, (c) anode and (e) cathode morphologies, (d) edx spectra of the anode and (f) edx spectra of cathode after the mec system run © 2023 the authors. page 15 of 19 satar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 13-19 3. results and discussion 3.1 electrode images before and after the experimental run the surface morphologies and element composition of electrodes before and after the mec system run were presented in figure 3. either anode or cathode surfaces before the mec system run was observed clean as shown in the typical image of gf surface (figure 3(a)). based on the sem-edx results, the main element on the electrode surface was carbon (c) with 100% of relative composition (figure 3(b)). meanwhile, the morphologies of anode and cathode surfaces after the experiment run were presented in figure 3(b) and (d) respectively. the c compositions at the anode and cathode surfaces were observed to be reduced to 70.1% (figure 3(d)) and 66.4% (figure 3(f)), respectively. these facts might due to the presence of other chemical components or impurities at the anode and cathode surfaces as a result of the oxidation and reduction reactions at their surfaces. furthermore, the mec systems were continuously supplied with the additional voltage from a power supply, thus the oxidation and reduction reactions occur during the mec system operation. according to some references, the presence of impurities on the electrode surface inhibits the bio-electrochemical reaction due to the current flow being slow (apostolopoulos et al., 2021; satar et al., 2020b; carmona-mart́ınez et al., 2015). consequently, the mec performance gradually dropped after three months of the system operation (carmona-mart́ınez et al., 2015). therefore, the anode and or cathode of the mec system is generally replaced with a new one before it is used again. 3.2 tww characterization the quality of tww before and after being treated with the mec system was evaluated to ensure whether the characteristics of tww meet the national standard of indonesia or not. the national standard of indonesia concerning the tww quality regulated by minister of environment of the republic of indonesia no. 5, 2014 was referred to in this work. some parameters of fresh tww such as ph, cod, bod, tss, tds, and ts were detailly measured (table 1). based on table 1 the ph of fresh tww was observed around 7.90. according to the regulation of government of yogyakarta special region, no. 7, 2016, concerning the wastewater standard (peraturan daerah diy, 2016), the ph of wastewater must be around 6.0 – 9.0 before discharge to the environment. based on this ph condition indicates the fresh tww can be discharged into the environment. it is well known the low ph of wastewater cause a negative impact on the ph of the soil, consequently, the nutrition absorption by plants is inhibited (rachmawati and wardiyati, 2018). furthermore, the low-ph wastewater may also interfere the marine life and aquatic biota (xu et al., 2023). hence, the fresh tww must be primarily treated before it discharges to the environment. in this work, the ph of fresh tww was treated by using the mec system. the final ph of tww was quite decreased to 7.16. this fact indicates the tww still be safely discharged into the environment. overall, the characterization of tww at the final mec run was presented in table 2. in addition to ph, the tss, tds, and ts were evaluated to ensure the physicochemical properties of tww meet with the regulation of government of yogyakarta special region no 7 2016. the physical properties of tss, tds, and ts involve the presence of solid impurities in tww. the high number of solid impurities in tww inhibits sunlight and oxygen entry into the water, consequently, marine life and or aquatic biota are disrupted. in this work, the tss, tds, and ts of the treated tww decreased around 35.0%, 45.5%, and 33.2% respectively. due to the tss, tds and ts were higher than the ts standard (200 mg/l), so further treatment must be conducted. for example, the filtration process can be used to reduce these solid impurities. furthermore, the cod value is principally indicated the number of organic matters that exist in a sample. in addition, the high bod value indicates a low number of dissolved oxygen (do) exists in the sample. based on two conditions which are the high cod and bod values harm the environment. this work shows the bod and cod values of tww were changed after it was treated with the mec system. the bod was decreased from 1400.10 mg/l to 490.0 mg/l (decrement of 35.0%), while the cod value was decreased from 1066.67 mg/l to 469.3 mg/l (decrement of 56.0%). the presence of eab at the anode of mec consumes the organic matter of tww during the mec operation. however, the final bod and cod values were quite high than the regulation, hence, the tww must be retreated more either chemical, biological or physical method. the high cod and bod values might be due to the low performance of the anode. the performance anode is very associated with the ability of eab to consume the organic pollutants. in this work, the mec system was only operated under normal conditions, consequently, the eabs might be poisoned by oxygen so their abilities were low. therefore, the mec system must fully be maintained at anaerobic conditions. 3.3 biohydrogen production and mec performance the phenomenon of the current trend at the enrichment and steady-state stages of the mec system run was shown in figure 4. at the enrichment stage in the mec anode, the generated current was observed very low (0.02 0.03 ma) for more than 20 days. there were very low gases produced from the system at the enrichment stage. whereas, the current production at the steady state was observed higher (0.4 ± 0.1 ma) for 10 days. however, the current generation was low due to there were no catalysts used at the cathode of mec, so the yh2 and qh2 were quite low. therefore, the chemical and or biological catalysts must be applied onto the cathode surface to enhance the h2 evolution reaction (her). © 2023 the authors. page 16 of 19 satar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 13-19 table 3. summary of h2 production from dual chamber mec using tww substrate and selected references parameters mec design dual chamber dual chamber dual chamber dual chamber anode-cathode gf-gf gf-gf/pt gf-cc/ssw gf-ni 201 substrate tww egf egf acetate eap (v) 1.0 1.0 1.0 0.9 yh2 (ml h2/gcod) 114.1 ± 0.1 553.6 ± 53.5 330 ± 30 qh2 (ml/l/d) 360 ± 20 590 ± 10 520 380 ± 40 references this work (satar et al., 2020b) (ribot-llobet et al., 2013) (selembo et al., 2009a) note: cc/ssw = carbon cloth combined with stainless wool; gf = graphite foam; gf/pt = graphite coated with pt catalyst; ni 201 = nickel allow 201; egf = effluent of glucose fermentation. principally, the overpotential at the cathode is high, hence, the catalysts are required to increase the total amount of h2 production (park et al., 2022). figure 4. typical current generation during h2 generation for 36 days of the experiment run hydrogen (h2) produced from the mec system was measured by using a syringe (50 ml) without further gc analysis. based on some literature the purity of h2 produced from the dual-chamber mec generally reached around 6977% (satar et al., 2020b; chae et al., 2010; selembo et al., 2009b; kadier et al., 2018). based on these references, hence, the purity of h2 produced in this work can also be assumed around 70%. after three consecutive cycles of biogas production, the total amount of gas volume was obtained at 68.1 ± 2.0 ml (or 48.1 ml of assumed h2) for 24 hours. the cod removal (∆cod) along with the system operation was obtained at 597 ± 10 mg/l. according to equation 1, the yh2 was calculated at around 8.87% (or 114.1 ml h2/g cod). meanwhile, the qh2 was calculated at around 360 ± 20 ml/l/d. this work demonstrated that the h2 can be generated by a dual chamber mec system using tww as substrate. however, the performance of mec (without cathode catalyst) using tww as substrate was quite lower than that of the selected references in table 3. as mentioned above this issue might be due to the rate of h+ reduction reaction to h2 at the cathode being quite slow. 4. conclusions the dual chamber mec system was successfully applied to treat tww and generated h2 at the same time. the tss, tds, ts, cod, and bod values of the final tww were reduced by approximately 45.5%, 35.0%, 33.2%, 56%, and 35%, respectively, lower than that of fresh tww. meanwhile, the ph decreased from 7.90 to 7.16. in addition, the yh2 and qh2 were obtained at approximately 8.87% (99.5 ± 0.1 ml h2/g cod) and 360 ± 20 ml/l/d, respectively. due to there being no catalyst on the cathode so the performance of dual chamber mec was lower than that of the selected reference. in the next research, the cathode of the dual chamber mec system will be coated with biological and or chemical catalysts to improve the yh2 and qh2. 5. acknowledgement the authors gratefully acknowledge the financial support given by the universitas ahmad dahlan (uad) via research sponsorship of pdp-341/sp3/lppm-uad/vi/2022. references apostolopoulos, i., g. bampos, a. soto beobide, s. dailianis, g. voyiatzis, s. bebelis, g. lyberatos, and g. 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energy, 34(13); © 2023 the authors. page 18 of 19 satar et. al. indonesian journal of environmental management and sustainability, 7 (2023) 13-19 5373–5381 son, s., b. koo, h. chai, h. v. h. tran, s. pandit, and s. p. jung (2021). comparison of hydrogen production and system performance in a microbial electrolysis cell containing cathodes made of non-platinum catalysts and binders. journal of water process engineering, 40; 101844 wulan, d. r., u. hamidah, a. komarulzaman, r. t. rosmalina, and n. sintawardani (2022). domestic wastewater in indonesia: generation, characteristics and treatment. environmental science and pollution research, 29(22); 32397–32414 xu, m., y. zhang, s. cao, y. li, j. wang, h. dong, and y. wang (2023). a simulated toxic assessment of cesium on the blue mussel mytilus edulis provides evidence for the potential impacts of nuclear wastewater discharge on marine ecosystems. environmental pollution, 316; 120458 ye, m. and y. y. li (2023). methanogenic treatment of dairy wastewater: a review of current obstacles and new technological perspectives. science of the total environment; 161447 © 2023 the authors. page 19 of 19 introduction experimental section materials methods tofu wastewater (tww) preparation and identification preparation of electrodes dual chamber mec set-up and operation gas analysis and calculation results and discussion electrode images before and after the experimental run tww characterization biohydrogen production and mec performance conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper biodegradation of methyl mercury by bacteria of empedobacter brevis in leachate melly anggraini1*, muhammad said2, suheryanto2, 1environmental management program, graduate program, universitas sriwijaya, jalan padang selasa, bukit besar palembang, indonesia 2chemical engineering department, faculty of engineeringuniversitas sriwijaya, jalan palembang prabumulih km 32 indralaya, indonesia 2chemistry deparment, faculty of science and mathematics, universitas sriwijaya, jalan palembang prabumulih km 32 indralaya, indonesia *corresponding author e-mail: anggrainimelly87@yahoo.co.id abstract leachate treatment containing methyl mercury (ch3hg +) can be done by using biodegradation method. bacteria used in methyl mercury biodegradation of the bacteria empedobacter brevis. this study aims to examine the ability of bacteria in degrading methyl mercury in leachate and determine the value of µ max and ks. the degradation process is done with variation of inoculum concentration and incubation time aerobically. the parameters analyzed were the decrease of methyl mercury content in the biodegradation process. the results showed that biodegradation of methyl mercury by the bacterium empedobacter brevis at 15% inoculum concentration was the highest decrease efficiency of 81%. the values of µ max and ks in the bacterium empedobacter brevis were 0.994 per hour with a substrate concentration of 1.588 mg /l. the reduction of methylmercury biodegradation process can be done by empedobacter brevis on leachate. keywords leachate, methyl mercury, inoculum concentration, incubation time, bacterial growth rate and substrate concentration received: 27 june 2018, accepted: 4 august 2018 https://doi.org/10.26554/ijems.2018.3.3.76-79 1. introduction garbage becomes a serious problem in big cities in indonesia along with increasing population and the limited land that will be used as final disposal place (tpa). dumps of waste that are left open in addition to causing odors also produce leachate. leachate is formed by the seepage of rain water that goes down the pile of garbage. leachate contains organic components, inorganic and heavy metals, one of which is mercury (ali, 2011; cabral et al., 2014). mercury is the only liquid metal compound at a normal temperature with a low vapor pressure (hua ding et al., 2007). mercury derived from both domestic and industrial waste into the waters in the form of mercury (hg0) that is partially bonded in the sediment and partially suspended in water. uv radiation causes mercury (hg0) to undergo photolysis reaction into mercury ions (hg2+). furthermore, mercury ions (hg2+) undergo methylation reactions with the help of microorganisms into methyl mercury compounds (ch3hg +) (li et al., 2015) methyl mercury (ch3hg +) is the most toxic compound among other mercury species. these compounds accumulate in the sediment and enter the food chain. methyl mercury accumulated in the food chain has high risk for top predators (chai et al., 2015). methyl mercury is a highly toxic compound because it can form lipophilic compounds that can cross the cell membrane, be absorbed easily and penetrate into the nervous system. methyl mercury is easily formed under the anaerobic reduction conditions from the final waste dumps through the reduction activity of sulfate and iron bacteria (chai et al., 2015). the effort to prevent the presence of methyl mercury in leachate does not pollute the environment by doing biodegradation method. bacteria empedobacter brevis is one of the bacteria in degrading methyl mercury. empedobacter brevis entered in the genus flavobacteriaceae which is a short rod-shaped bacteria, non-motile, gram negative and aerobic. all strains grow at 30°c and there are several strains that grow at 37°c. this bacterium has a width of 0.5 µ m and a length of 1-2 µ m (hua ding et al., 2007). the purpose of this study is to assess the ability and determine the degradation kinetics of the bacteria empedobacter brevis in degrading methyl mercury in leachate that is influenced by variation in the number of inoculum and incubation time. https://doi.org/10.26554/ijems.2018.3.3.76-79 anggraini et. al. indonesian journal of environmental management and sustainability, 3 (2018) 76-79 2. experimental section 2.1 materials lysogeny broth (lb), a nutritionally rich medium is mainly utilized for the growth of bacteria. the lb is also regularly, albeit incorrectly, taken to mean luria broth, lennox broth, or luriabertani medium. in this study, we used luria-bertani broth which is from darmstadt, germany. luria-bertani broth is the most common media to maintain and cultivate empedobacter brevis. on the other hand, we analyzed methyl mercury by using toluene, acetone, hcl and nacl. 2.2 preparation of bacteria inoculum the bacteria of empedobacter brevis from the skewed medium were taken 2-3 ose aseptically placed into an erlenmeyer containing 50 ml of lb broth. empedobacter brevis incubated for 24 hours at room temperature (±30°c) above shaker with agitation speed of 160 rpm. 2.3 biodegradation methyl mercury in leachate the bacterial inoculum was taken by the variation of bacterial concentrations around 15% (v/v), 20% (v/v), and 25% (v/v) were inoculated into leachate and incubated for 4, 8, and 24 hours with agitation speed 160 rpm at room temperature 30°c. calculation of bacteria in substrate was done in every incubation time interval that is 4, 8 and 24 hours. the number of bacteria was calculated using total plate count (tpc) method then the methyl mercury content was analyzed by gas chromatography mass spectrometry. the research design used was complete randomized design with factorial pattern, with combination of treatment as presented in table 1. 2.4 calculation efficiency of decreased methyl mercury content the efficiency of methyl mercury content is calculated with the following equation: e f f = c2 −c1 c2 x100% (1) where: c1 = initial concentrations (mg/l) c2 = final concentration (mg/l) eff = efficiency (%) 2.5 kinetics of microbial degradation bacterial degradation can be calculated kinetically to determine the value of bacterial growth rate (µ max) and substrate saturation constant value (ks) by using monod equation with lineweaverburk method. µ = µ m s ks + s (2) notes : µ = specific growth rate (min−1) µ m = max specific growth rate (min−1) s = residual concentration of growth substrate (m/v) ks = the saturation constant equals the substrate concentration (m/v) 3. results and discussion 3.1 empedobacter brevis growth curve growth is the regular addition of all components of a microorganism. the growth of microorganisms can be measured based on cell concentration or cell density (dry weight from cells of cell contents). calculating cell density can be seen from the absorbance value of contents (diana, 2013). the growth of microorganisms is an indicator that ca be decreased heavy metals in leachate. the growth of microorganisms will increase if it is able to live by utilizing the substrates present in the leachate. based on the measurement of absorbance with the number of colonies, the standard growth curve of empedobacter brevis is y = 3040.6 x 1931.1, with correlation (r) = 0.9239. these standard curve equations can be calculated the number of empedobacter brevis as seen in figure 1. the adaptation phase of empedobacter brevis occurred at the 0th hour until the 2nd hour, while the exponential phase of empedobacter brevis on each variation of methyl mercury concentration occurred at the 4th hour until the 28th hour. the stationary phase is characterized by the growth of bacterial cells that are almost constant or have very little growth of the bacteria empedobacter brevis occurred at hours 28 to hours 56. the phase of death of the bacterium empedobacter brevis occurred at the 56th hour. 3.2 the empedobacter brevis effects of bacterial concentration and incubation time in leachate biodegradation research of methyl mercury in leachate used empedobacter brevis with various inoculum concentrations or specific size. giving various concentrations of this inoculum aims to determine which inoculum concentration is optimum to support bacterial growth and has a high absorption of methyl mercury. the influence of bacteria in certain amounts, especially bacteria that are adaptive, resistant to polluted media and can bind heavy metals because microbes produce extracellular or synthetic table 1. table combination treatment bacterial concentration incubation time b1 (4 hours) b2 (8 hours) b3 (24 hours) a1 (15%) a1b1 a1b2 a1b3 a2 (20%) a2b1 a2b2 a2b3 a3 (25%) a3b1 a3b2 a3b3 © 2018 the authors. page 77 of 79 anggraini et. al. indonesian journal of environmental management and sustainability, 3 (2018) 76-79 figure 1. growth of empedobacter brevis in the variation of metilmercury concentration enzymatic compounds capable binding heavy metals through adsorption processes (hughes and r.k., 1989; khoiroh, 2014). the biosorbtion mechanism was capable for living in a polluted environment of heavy metals. this mechanism occurs simultaneously with the consumption of metal ions for the growth of microorganisms (the intracellular accumulation of metal ions) (khoiroh, 2014). the number of microbes that increase can lead competition between microbes. this form of competition can be a fight for space, water and nutrient (khoiroh, 2014). the competition between bacteria cause growth and degradation process will be low. the ability of biosorption from microbe is influenced by several factors such as group of gram positive and negative bacteria. gram-negative bacteria are generally more tolerant of heavy metal influences than gram-positive bacteria because of their complex cell wall structures which can bind and immobilize most metal ions including ch3hg +. the metals are bonded to carboxyl groups on the peptide and peptidoglycan chains and phosphate figure 2. the influence of bacterial concentration and incubation time of empedobacter brevis in leachate groups of lipopolysaccharides. similarly, the presence of plasmids in bacteria can cause bacteria resistant to heavy metals (hughes and r.k., 1989; li et al., 2015). the methyl mercury decrease with various treatments of inoculum concentration at incubation time 0, 4, 8 and 24 hours can be seen in figure 2. the initial methyl mercury was 0.633 ppm. the lowest decrease of methyl mercury occurred at 15% treatment around 0,124 at incubation time 24 hours which has efficiency decreased methyl mercury content around 81%. the bacteria concentration treatment at 20% was 0,128 with efficiency decreased methyl mercury content around 80%. the treatment at 25% inoculum concentration was 0,326 with efficiency decreased methyl mercury content around 48%. the results showed that the small concentration of bacterial inoculum in empedobacter brevis improved the degradation process. the longer the incubation time, the lower the methyl mercury level exist in the leachate. the suitability between the inoculum concentration ratio and the substrate composition may affect the degradation process of methyl mercury. the decrease in methyl mercury levels at 15% and 20% inoculum concentrations did not differ greatly. so, the inter-population competition on the treatment resulted the bacteria adapting to use other substrates table 2. the values of kinetic parameters for methyl mercury biodegradation in leachate sample code growth rate, µ (generation/hour) generation time, g (hour) µmax ks a1b1 0,994 1,588 a1b2 0,126 7,936 a1b3 0,016 62,5 a2b1 0,347 0,868 a2b2 0,007 142,857 a2b3 0,004 250 a3b1 0,007 0,365 a3b2 0,033 30,303 a3b1 0,002 500 © 2018 the authors. page 78 of 79 anggraini et. al. indonesian journal of environmental management and sustainability, 3 (2018) 76-79 other than carbon (sucipto, 2009). 3.3 kinetics degradation methyl mercury by empedobacter brevis growth rate and generation time need to be calculated, because the relationship between growth rate and generation time to process time can be known in determining the optimum time. the optimum time of the process is marked by the lowest generation time and the highest biomass growth rates. the lowest generation time is the shortest time required to increase the number of cells becoming double from the original amount shown in table 2. the biomass growth rate showed the bacterial population changes per unit of time, the low growth rate indicated the slow growth of microorganisms and vice versa. the lowest generation time and highest biomass growth rate for bacteria empedobacter brevis at 15% inoculum concentration was the 8th hour that was the growth rate of bacteria was 0,126 generation per hour with time generation 7,936 hour. the highest generation time and the lowest biomass growth rate for the bacterium empedobacter brevis at 25% inoculum concentration was the 24th hour with the bacterial growth rate around 0.002 generations per hour and the generation time around 500. the low growth rate signified the slow growth of microorganisms (romli, 2012). substrate concentration is a limiting factor of bacterial growth; a culture will achieve maximum biomass concentration as it approaches the end of the growth phase. the greater value of ks indicated the substrate concentration was sensitive to the growth of microorganisms. the maximum growth rate (µ max) was the maximum value of the growth rate at the peak during the exponential phase before entering the stationary phase (fahria and laksmono, 2014). the maximum growth rate of empedobacter brevis bacteria was highest at 15% inoculum concentration of 0.994 per hour with a substrate concentration of 1.588 mg/l. the 20% inoculum concentration of 0.347 per hour showed substrate concentration around 0.868 mg/l and the lowest maximum at 25% inoculum concentration of 0.007 per hour indicated substrate concentration around 0.365 mg/l. 4. conclusions the highest efficiency of methyl mercury reduction in methyl mercury biodegradation process by empedobacter brevis on leachate is at 15% inoculum concentration with a percentage decrease of 81%, this is the same with the kinetics value of bacterial biodegradation which has the bigger growth rate and the faster growth of microorganism. the highest maximum growth rate at 15% inoculum concentration is 0.994 generations per hour with a substrate concentration of 1.588 mg/l. references ali, m. (2011). water seed lands monograf (leachate) impacts on food crops and health cabral, l., p. giovanella, a. kerlleman, c. gianello, f. m. bento, and f. a. o. camargo (2014). impact of selected anions and metals on the growth and in vitro removal of methylmercury by pseudomonas putida v1. international biodeterioration & biodegradation, 91; 29–36 chai, x., y. hao, z. li, w. zhu, and w. zhao (2015). the dependence of the methylation of mercury on the landfill stabilization process and implications for the landfill management. chemosphere, 119; 828–834 diana, n. (2013). potential bacteria enterobacter agglomerans as lead weight lead biosorbent (pb). master’s thesis, jurusan biologi fakultas sains dan teknologi universitas islam negeri maulana malik ibrahim malang fahria, m. and r. laksmono (2014). kinetics of organic matter biodegradation in waste water of leachate. jurnal ilmiah teknik lingkungan, 4(2) hua ding, z., q. he tang, c. e liu, w. hua wang, m. zhuang, and y. ming lin (2007). distribution and ecological effect of mercury in laogang landfill, shanghai, china. journal of environmental sciences, 19(2); 200–204 hughes, m. and p. r.k. (1989). metals and microorganism. chapman and hall ltd, london, uk khoiroh, z. (2014). lead metal bioremediation lead (pb) in lapindo mud using bacterial blends (pseudomonas pseudomallei and pseudomonas aeruginosa). master’s thesis, uinmalang, malang indonesia li, a., l. ye, f. guo, x. yang, and h. yu (2015). biocatalytic anti-prelog reduction of prochiral ketones with whole cells of a newly isolated strain empedobacter brevis zjuy-1401. journal of molecular catalysis b: enzymatic, 117; 31–37 romli, m. (2012). penentuan nilai parameter kinetika lumpur aktif untuk pengolahan air lindi sampah (leachate). master’s thesis, departemen teknologi industri pertanian, fakultas teknologi pertanian, institut pertanian bogor sucipto, i. (2009). biogas fermented hydrolisate bagas using consortium of thermophilic bacteria cow manure. institut pertanian bogor © 2018 the authors. page 79 of 79 introduction experimental section materials preparation of bacteria inoculum biodegradation methyl mercury in leachate calculation efficiency of decreased methyl mercury content kinetics of microbial degradation results and discussion empedobacter brevis growth curve the empedobacter brevis effects of bacterial concentration and incubation time in leachate kinetics degradation methyl mercury by empedobacter brevis conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper the correlation analysis of maintenance costs to sei siulak deras irrigation network infrastructure performance frans dhana1*, dinar dwi anugerah putranto2*, betty susanti2*, 1civil engineering graduate program of sriwijaya university, palembang, indonesia 2civil engineering department, faculty of engineering, sriwijaya university, palembang, indonesia *corresponding author e-mail: : fransdhana1979.fd@gmail.com; dwianugerah@yahoo.co.id; b_susanti@yahoo.com abstract sei siulak deras irrigation area is one of the irrigation areas located in kerinci regency based on the decision of dinas pekerjaan umum dan perumahan rakyat (pupr) regulations no.12/prt/m/2015 concerning criteria and estabishment of irrigation area status with an area of 5,801 ha. the authority for operational and maintenance implementation is handled by the dinas pupr of jambi province. the performance of the sei siulak deras irrigation network infrastructure is inseparable from the available maintenance budget, for this reason, it is necessary to conduct a study that analyzes the relationship between routine maintenance costs for the performance of irrigation network infrastructure in the sei siulak deras irrrigation area of kerinci district, jambi province. in this study an examination of the existing conditions of irrigation networks involving 1 observer and 6 irrigation workers, the irrigation network inspection using the standards issued by the operation and maintenance agency of the dinas pupr of jambi province. from the results of the correlation analysis the cost of routine maintenance on the performance of irrigation network infrastructure is 0.9, this indicates a strong relationship between the two variables. while the maintenance budget allocated by the government to the maintenance of irrigation network infrastructure is very lacking, amounting to idr 806,081,000 from the budget for the maintenance of irrigation network infrastructure of idr 3,580,984,372.57. keywords correlation, maintenance cost, index perpormance received: 15 april 2019, accepted: 3 june 2019 https://doi.org/10.26554/ijems.2019.3.2.71-74 1. introduction jambi province is one of the provinces in indonesia which has launched a rice self-su�ciency program. to support this program, good irrigation infrastructure is certainly needed. one of the regencies in jambi province which has a strategic area in irrigation development is kerinci regency which is located at the western end of jambi province, with a position between 01°40’ to 02°26’ south latitude and between 101°08’ to 101°50’ east longitude, with wide area of 332.807 ha atau 3.328,07 km2. the existence of the sei irrigation area. siulak deras with an area of 5,801 ha, which is located in kerinci regency is be appointed based on dinas pekerjaan umum dan perumahan rakyat (pupr) regulation no.12/prt/m/2015 concerning criteria and determination of irrigation area status. while the authority over the implementation of operations and maintenance is handled by dinas pupr of jambi province (rtrw, 2013) . the performance of irrigation network infrastructure is inseparable from the operational costs and available maintenance costs, where this funding is budgeted in the state budget plan (rapbn) and the implementation authority is handed over to the provincial government as stipulated in government regulation no. 20 of 2006. funding for operations and maintenance is closely related to the ability of facilities and infrastructure to achieve high performance, so that limited funds can result in one or several activities not being able to be implemented, therefore managers must be able to choose the priority of operations and maintenance activities to be carried out. the fund arrangement for available operations and maintenance is regulated based on the water resources act number 7 of 2004 which consists of the government budget, private budget, and proceeds from the cost of water resources management. the operational and maintenance costs of this irrigation network include several aspects, ie the condition of physical infrastructure, planting productivity, supporting facilities, personnel organizations, documentation, and the condition of the water user farmers association (p3a)services (permen pupr no. 12/prt/m/2015). several studies have been conducted about the operational and maintenance costs of irrigation networks, as well as the performance of irrigation https://doi.org/10.26554/ijems.2019.3.2.71-74 dhana et. al. indonesian journal of environmental management and sustainability, 3 (2019) 71-74 networks (susanti, 2016; sumaryanto, 2006; sofyan, 2012) . study on the magnitude of the relationship of maintenance costs to the performance of irrigation infrastructure needs to be done so that the relationship between maintenance costs and the performance of irrigation networks is obtained, especially routine maintenance that is directly used in daily activities during the operation and maintenance of irrigation networks. this research was conducted to analyze the relationship between the cost of routine maintenance to the performance of irrigation network infrastructure in the siulak deras irrigation area of kerinci regency, jambi province. so that the results of this study are expected to be used as a guideline for the government in the provision of the operating and maintenance budget for the irrigation network sei siulak deras irrigation area. 2. experimental section 2.1 classi�cation method in this study an examination of the existing conditions of sei siulak deras irrigation network involving 1observer sta� from the dinas pupr of jambi province in the �eld of water resources while 6 irrigation workers from the irrigation �eld. the criteria for performance appraisal used in the inspection of irrigation networks use the standards issued by the management and maintenance agency of the dinas pupr of jambi province. inspection of irrigation networks is carried out through tracing irrigation networks to record irrigation network damage starting from the building to the canals by tracing irrigation structures and networks using gps and metres. secondary data used in this study include location maps, data on the condition of the irrigation network sei siulak deras in the last 5 years, the amount of the operating and maintenance budget available, and other data related to research. the study area in the sei siulak deras irrigation area located in kerinci regency, jambi province, between 104°56’36” to 104°57’20” east longitude and 3°6’40” to 3°7’30” south latitude, with an area of 199 ha. the study area can be seen in figure 1. figure 1. study area (source : dinas pupr of jambi province) 2.2 analysis method data processing is done using ms. excel to get a correlation between the cost of routine maintenance and the performance of irrigation network infrastructure. furthermore, the comparison of operational funding requirements and routine maintenance of network infrastructure performance will be analyzed using an analysis of unit cost prices which refers to the analysis of unit prices issued by the dinas pupr of jambi province. research flow chart can be seen in figure 2. figure 2. diagram alir 3. results and discussion 3.1 analysis of physical infrastructure performance index the physical infrastructure performance index of the sei. seulak deras irrigation area by using the criteria of the assessment of management and maintenance agency of the dinas pupr of jambi province can be seen in table 1. table 1 shows that the average performance index value of existing irrigation networks is below the optimum value, which is equal to 65.69%, in order to improve performance it must be maintained the performance of the irrigation physical network. handling of maintenance must be pay attention to the priority of the maintenance based on the comparison between the existing performance index value and the optimum performance index value, so that handling of maintenance is on target. if seen from the biggest di�erence between the optimum performance value and the value of the existing performance, the priority for handling maintenance is "physical infrastructure", namely the di�erence of 8.74%. 3.2 cost analysis of routine maintenance based on the performance index of the inspection result of irrigation networks, the main priority in handling maintenance is on physical infrastructure, futhermore was done the calculation of the routine maintenance costs for the physical infrastructure of the irrigation network so the amount of routine maintenance costs needed for the physical infrastructure of the irrigation network sei siulak deras was obtained. the calculation of the © 2019 the authors. page 72 of 74 dhana et. al. indonesian journal of environmental management and sustainability, 3 (2019) 71-74 table 1. sei siulak deras irrigation network physical performance index no indicator performance index (%) existing and optimum existing max min optimum comparison 1 physical infrastructure 26.26 45 25 35 8.74 2 planting productivity 12.78 15 10 12.5 0.28 3 supporting facilities 3.55 10 5 7.5 3.95 4 personnel organization 12.1 15 7.5 10 2.1 5 documentation 3.5 5 2.5 5 1.5 6 water user farmers association (p3a) 7.5 10 5 7.5 0 irrigation network physical 65.69 100 55 77.5performance index table 2. budget plan for routine maintenance of physical infrastructure no job description cost (idr) 1 main building 31,715,087.00 2 carrier channel 1,344,540,902.00 3 building on the carrier channel 2,204,728,328.28 total 3,580,984,372.57 table 3. the routine maintenance budget of the last 5 years sei siulak deras irrigation network can be seen in table 3 no. years maintenance costs of irrigation networks sei siulak deras (idr) 1 2014 725,121,000 2 2015 725,121,000 3 2016 978,991,000 4 2017 742,481,000 5 2018 806,081,000 (source: dinas pupr of jambi province, 2019) budget for work is carried out on 3 main buildings, namely the main building, the carrier channel, and building on the carrier channel. the results of the calculation of the routine maintenance costs in the irrigation network sei siulak deras, can be seen in table 2. table 2 shows that the largest infrastructure maintenance costs are in the carrier channel, which is equal to idr 2,204,728,328.28 or about 62% of the total maintenance budget, which is idr 3,580,984,372.57. 3.3 available budget allocation of funds the routine maintenance of the sei irrigation network sei siulak deras is charged in the state revenue and expenditure budget (apbn) every year. the amount of the routine maintenance budget in the last 5 years can be seen in table 3. table 3 shows that the government budget for the maintenance and operation of the sei siulak deras irrigation network. sei siulak deras averages under idr 1,000,000,000 annually, while the budget needed for routine maintenance is idr 3,580,984,372.57. 3.4 analysis of maintenance cost correlation on network infrastructure performance from the irrigation network performance index value, maintenance budget, and available fund allocation, it can be seen that the budget provided is still far from the funds needed for routine maintenance of sei siulak deras irrigation network infrastructure, so that it is not possible to maintenance maximum. maintenance that is not optimal can certainly cause a decrease in the performance of existing irrigation infrastructure. the performance index of sei siulak deras irrigation channel in 2014 to 2017 is as follows: 31.00; 31.20; 24.10; 30.40 (pupr, 2019) , while the value of the irrigation performance index in 2018 is obtained from the results of examination which is equal to 26.26. from the results of the correlation analysis calculations using ms. excel was obtained a correlation value of 0.9, this indicates that there is a strong relationship between maintenance costs to the performance of sei siulak deras irrigation network infrastructure. the higher the correlation value, the stronger relationship between the two variables. 3.5 discussion damage to irrigation canals is caused by several factors, such as the presence of sediment, garbage, or the age of channels. however, maintenance e�orts carried out by the government are still insu�cient, this is evidenced by the lack of maintenance costs budgeted by the government for the maintenance of irrigation networks, especially the irrigation network sei siulak deras. this of course must be a top priority for the government in setting maintenance budgets, especially routine maintenance of irrigation network infrastructure by considering the budget needs of the irrigation network maintenance itself, because there is a strong relationship between maintenance costs and irrigation network infrastructure performance. 4. conclusions the correlation analysis results of routine maintenance costs for the performance of irrigation network infrastructure was © 2019 the authors. page 73 of 74 dhana et. al. indonesian journal of environmental management and sustainability, 3 (2019) 71-74 0.9, this indicates that there is a strong relationship between the two variables. while the maintenance budget allocated by the government to the maintenance of irrigation network infrastructure is very lacking, namely as much as idr 806,081,000 from the total budget for the maintenance of irrigation network infrastructure of idr 3,580,984,372.57. 5. acknowledgement acknowledgements for dinas pupr of jambi province. references pupr (2019). rekapitulasi realisasi pelaksanaan paket-paket pekerjaan. dinas pekerjaan umum dan perumahan rakyat provinsi jambi rtrw (2013). rencana tata ruang dan wilayah sofyan, a. (2012). kajian kinerja operasi dan pemeliharaan jaringan irigasi studi kasus daerah irigasi cokrobedog provinsi daerah istimewa yogyakarta. master’s thesis, universitas gadjah mada, yogyakarta. sumaryanto (2006). peningkaan e�siensi penggunaan air irigasi melalui penerapan iuran irigasi berbasis nilai ekonomi air irigasi. forum penelitian agro ekonomi, 24(2) susanti (2016). analisis faktor-faktor yang mempengaruhikinerja operasi dan pemeliharaan jaringan irigasi di kota sungai penuh. universitas bung hatta © 2019 the authors. page 74 of 74 introduction experimental section classification method analysis method results and discussion analysis of physical infrastructure performance index cost analysis of routine maintenance available budget allocation of funds analysis of maintenance cost correlation on network infrastructure performance discussion conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper addition effect of petrasoil additive material on cbr value of soil in swamp areas andi herius1, indrayani1*, arfan hasan1, ahmad mirza1 1civil engineering department, state polytechnic of sriwijaya, palembang, indonesia *corresponding author e-mail: iin_indrayani@polsri.ac.id abstract some road construction projects use petrasoil additive to increase soil stabilization, one of then is the improvement of tabarfanehokmar (chemical petrasoil) road project in aru selatan timur district, aru islands. to obtain the influence of petrasoil aditive material as soil stabilization in swamp areas, a research is needed. petrasoil additives that powder shape are dissolved in water with 3 variations, namely 500 liters, 750 liters, and 1000 liters of water. tests which carried out include compaction testing, index properties, and cbr. the results showed that the addition of petrasoil mixture with water without being combined with other added ingredients could lead to increasingly unstable soil conditions where the soil water content increased and the dry weight of the soil diminished, meaning that soil density decreases, and the cbr value of soil decreases. keywords petrasoil, cbr value received: 28 may 2019, accepted: 13 june 2019 https://doi.org/10.26554/ijems.2019.3.2.67-70 1. introduction south sumatra is one of the provinces in indonesia that has a fairly large swamp area of around 613,795 hectares consisting of 455,949 hectares of tidal swamps and 157,856 hectares of non tidal swamp (bws, 2015) . road infrastructure which built on swamp area must pay attention to the existing subgrade conditions because the characteristics of swamp soil are saturated of water and have low carrying capacity soil (subagyo, 2006) . various e�orts have been made to improve the existing subgrade conditions including utilizing �y ash as a material for soil stabilization (indrayani et al., 2018; indera et al., 2016; mina et al., 2015). nowdays several road construction projects add petrasoil to increase soil stabilization, among others in the improvement of tabarfane-hokmar (chemical petrasoil) road project in sub district of south east . in this study, the addition of petrasoil to the soil without other materials so was obtain the e�ect of petrasoil addition in increasing soil stabilization in swamp areas. 2. experimental section 2.1 classi�cation method soil samples were taken from swamp soil and then were added petrasoil which had been dissolved in water with 3 size variations so the e�ect of petrasoil addition on the carrying capacity of the soil was obtained. the location of land extraction in this study was in the banyuasin district which consisted of a large portion of the swamp area, the topography of the area consisted of 80% wet lowlands with a slope of 0 8%, consisting of tidal swamps, non tidal swamps and coastal. while laboratory tests were carried out at the sriwijaya state polytechnic material test laboratory. petrasoil obtained from suppliers pt. sa. nusantara pt. basuki rahmanta putra. the parameters to be tested include: compaction testing, testing properties index (gs/ speci�c gravity, moisture content, weight content), sieving analysis, hydrometer, atterberg boundary and cbr testing. combination of adding petrasoil that dissolved in water in a ratio of 1 kg petrasoil to 500 liters of water; 750 liters of water; and 1000 liters of water. 2.2 analysis method samples location which were taken were based on the results of previous studies namely clay soil in the swamp area precisely in the district of tanjung lago district. this research is a continuation of previous reseacher on the studied of land in swamp areas, so that the chosen location is one point of 10 sampling points. the location of land sampling can be seen in figure 1. laboratory testing guidelines used the sni, aashto and astm standards (aashto, 1998; astmc618, 1994; sni0317421989, 1989) . 3. results and discussion 3.1 index properties testing speci�c gravity is the ratio of the weight of soil grains to the volume of soil grains at a certain temperature. speci�c gravity testing results can be seen in the figure 2. https://doi.org/10.26554/ijems.2019.3.2.67-70 herius et. al. indonesian journal of environmental management and sustainability, 3 (2019) 67-70 figure 1. samples location figure 2. the average test results of speci�c gravity speci�c gravity test results show that the value of density is decreased by 0.06 (from 2.66 to 2.60) with petroloil addition with a mixture of water, this means that the addition of petrasoil without other added ingredients can cause a decrease in soil speci�c gravity. testing atterberg boundaries is done to get the liquid limit, plastic limit, and soil plasticity index. the average test results of atterberg boundaries can be seen in figure 3. the results of the liquid limit test indicate that the addition of petrasoil causes the liquid limit to increase from 36.87% to 57.60% by a water variation of 500 liters; 57.64% by a water variation of 750 liters ; and 56.83% by a water variation of 1,000 liters. the higher the liquid limit on the soil cause the soil to become more unstable, because water is very in�uential on soil stability. while the results of the plasticity index test show that the soil plasticity index has increased with the addition of petrasoil whereas the higher the plasticity index will showed that the soil conditions increasingly not conducive to the civil construction. petrasoil addition to soil without other added ingredients can cause an increase in soil consistency limits. from the test results it can be seen that the highest increase in the plasticity index is the addition of 750 liters of water but figure 3. the average test results of atterberg boundary in the addition of 1000 liters of water, there is a decrease in the liquid limit and the plasticity index. for this reason, it is necessary to carry out further research on water variations of more than 1000 liters. grading test is done to get the size of the grain before and after added petrasoil, the average test results of gradations can be seen in figure 4. figure 4. the average test results of gradations the gradation test results showed that the soil with petrasoil additions which passed the 0.075 mm sieve had increased because the soil grains become smoother. 3.2 compaction testing compaction testing is carried out to determine the optimum water content and maximum soil density. the average results of testing the optimum moisture content can be seen in figure 5. the graph in �gure 5 shows that with the addition of petrasoil mixed with water resulting in an increase in soil water content, from 15.26% to 19.73% on a variation of 500 liters of water, and 22.57% on a variation of 750 liters of water, and 23.48 % on a variation of 1000 liters of water. the more addition of the mixture of petrasoil and water will cause an optimum increase in water content. this means that the addition of petrasoil without other added ingredients is not recommended for soil improvement because the higher the water content the © 2019 the authors. page 68 of 70 herius et. al. indonesian journal of environmental management and sustainability, 3 (2019) 67-70 figure 5. the average test results of optimum water content figure 6. the average test results of dry weight soil conditions will become more unstable. while the average test results of dry weight can be seen in figure 6. figure 6 shows that occure a decrease of the dry weight of the soil by additions a mixture of petrasoil and water, ie on the variation of 500 liters of water from the weight of 1.761 gr/cm3 to 1.242 gr/cm3, on the variation of 750 liters of water to 1.196 gr/cm3, and at the variation of 1000 liters of water to 1,231 gr/cm3. this shows that the addition of petrasoil without other added material mixtures can cause a decrease in the dry weight of the soil so this means that the soil density decreases, with reduced soil density will cause the soil conditions to be unstable for construction buildings, so the petrasoil mixture cannot be used for soil repairs without other added ingredients. 3.3 testing of cbr value the average results of testing the cbr value of the original soil and cbr with additional of petrasoil at variations in water can be seen in figure 7. 3.4 discussion mechanical, physical and chemical soil stabilization carried out at this time aims to improve soil conditions. petrasoil figure 7. result of cbr value use in some road constructions is always combined with other materials such as cement or lime. from this results of this study was obtained that the addition of petrasoil dissolved in water without being combined with other added ingredients can cause the soil conditions to become more unstable where the soil water content is higher, while the soil with high water content is not good for road construction, besides that causing dry soil weight diminishing means that the soil density is getting lower so that the land becomes unstable, as well as the cbr value was decreasing, it is means that the carrying capacity of the land is getting lower. petrasoil content as stabilizing material on the soil must be considered, and the use of petrasoil as a supplement to added material in the soil improvement e�ort must also be taken into account so that further research is needed on the petrosoil itself and the e�ect of adding petrasoil as an added material to the soil. 4. conclusions there was a decrease in cbr value in the addition of petrasoil with 500 liters of water ie was from 22.85% to 12.79%, while the cbr value increased in petrasoil addition with 750 liters of water and 1000 liters but the increase in cbr value was still below the cbr value under normal conditions . the results showed that the addition of petrasoil without being combined with other added ingredients could lead to increasingly unstable soil conditions where the soil water content increased and the dry weight of the soil diminished, meaning that soil density decreases and the cbr value of the soil decreases. 5. acknowledgement acknowledgements for state polytechnic of sriwijaya, palembang, indonesia. references aashto (1998). standard speci�cation for transportation materials and methods of sampling and testing part i : speci�cation. 19th edition. american association of state highway and trasportation o�cials, washington d c © 2019 the authors. page 69 of 70 herius et. al. indonesian journal of environmental management and sustainability, 3 (2019) 67-70 astmc618 (1994). standard speci�cation for coal fly ash and raw calcined natural pozolan for use in concrete bws (2015). pro�l balai wilayah sungai sumatera viii indera, r., e. mina, and t. rahman (2016). stabilisasi tanah dengan menggunakan fly ash dan pengaruhnya terhadap nilai kuat tekan bebas. jurnal fondasi, 5(1) indrayani, a. herius, a. hasan, and a. mirza (2018). comparison analysis of cbr value enhancement of soil type in swam area by addition of fly ash. science and thechnology indonesia, 3(2); 73–76 mina, e., r. kusuma, and i. subowo (2015). pengaruh fly ash terhadap nilai cbr dan sifat-sifat properties tanah (studi kasus : jalan raya bojonegoro km 19 serang banten). jurnal fondasi, 5(2) sni0317421989 (1989). testing methods about soft density for soil sni0319641990 (1990). testing methods about speci�c gravity sni0319651990 (1990). testing methods about water content sni0319661990 (1990). testing methods about plasticity index sni0319671990 (1990). testing methods about liquid limit sni0319681990 (1990). testing methods about sieve analysis subagyo, h. (2006). karakteristik dan pengelolaan lahan rawa. badan penelitian dan pengembangan pertanian, departemen pertanian, bogor © 2019 the authors. page 70 of 70 introduction experimental section classification method analysis method results and discussion index properties testing compaction testing testing of cbr value discussion conclusions acknowledgement indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article received: 13 october 2017 accepted: 13 february 2018 *corresponding author email: tato.endarto@gmail.com doi: 10.26554/ijems.2018.2.1.1-61 evaluation of concatenation planning of crushing plant production system using analytic hierarchy process (ahp) method at pt buana eltra coal processing unit, south sumatra endarto1, restu juniah1 and weny herlina3 1department of mining engineering, faculty of engineering, university of sriwijaya, roadway of palembang-prabumulih km.32 inderalaya, south sumatera, 30662, indonesia abstract coal processing activity conducted at the coal processing unit (stockpile) martapura pt. buana eltra aims to reduce the size of coal to a smaller size in accordance with market demand of 5-10 cm. processing is done with a combination of crushing plant and excavator called concatenation of production system. concatentation of the current production system is a concatenation between komatsu pc300 excavator and 10 cm roll crusher dimension which produces 145,6701 tons/hour and takes 20,59 hours and is considered inefficient and ineffective to reach production target of 3000 tons/day. based on the above, it is necessary to evaluate the concatenation of crushing plant production system so that the processing process will be optimally. the method used in this concatenation evaluation is the analytic hierarchy process (ahp) method. the alternative is the concatenation between, komatsu pc200 excavator 10 cm roll crusher dimension, komatsu pc200 excavator 5 cm roll crusher dimension and komatsu pc300 excavator 5 cm roll crusher dimension. the selection of these alternatives is based on qualitative data (criteria from experts) and quantitative data so as to produce optimal choice. based on the evaluation and analysis of the two types of data then selected concatenation excavator komatsu pc200 dimension roll crusher 10 cm which has a productivity of 207,8468 tons/hour and the time required to reach 300 tons/day for 14.43 hours. keywords: concatenation, production system, ahp. 1. introduction coal is one of the energy sources utilized in various industries such as steam power plant (pltu), metallurgy processing, cement making mixture, paper industry, textile industry, briquette making and others. based on domestic market obligation (dmo) data released by the ministry of energy and mineral resources, national coal demand will continue to increase in 2017 with estimates reaching. 133.61 million tons, up 3.19 percent or 3.86 million tons higher than the target set in the 2015-2019 national medium term development plan (rpjmn) of the original dmo target of 124.85 million tons from production of 413 million tons and will be expected to increase further in the following year by 151.86 million tons. the coal requirement for next year's power plant is estimated to reach 86 million tons, up from this year's projection of 74 million tons. coal needs for power plants will reach 119 million tons in 2019, while for 2016 metallurgical activities by pt krakatau steel tbk (kras) is estimated to reach 4.65 million tons. the demand for supplies to pt krakatau stel is 968 thousand tons, pt krakatau posco rp 2,195 million tons and pt meratus jaya iron & steel 400 thousand tons. other supplies for two metallic mineral companies, pt aneka tambang tbk (antam) and pt vale indonesia tbk (inco) require different coal in 2017. antam raised its coal requirement to 885 thousand tons from this year's projection of 565 thousand vale tondan tends to be stagnant, which is 200 thousand equals this year, while for the fertilizer industry, next year's demand is estimated at 1.98 million tons which will be supplied to pt pupuk sriwijaya with 705 thousand tons, pt petrokimia gresik 475,200 tons and pt pupuk kaltim 800 thousand tons, while for cement industry requires a coal increase to 10.88 million tons from this year's 10.54 million tons. coal supply for pt semen indonesia tbk (smrg) increased by 6.189 million tons from this year's 5.99 million tons. the rest is allocated 1.85 million tons for pt holcim indonesia tbk and other cement 2.84 million tons. the increasing demand of national coal encourages every coal company to continue its efforts to increase its productivity, as well as with various coal companies located in south sumatra, one of them, pt buana eltra located in ogan komering ulu district. pt buana eltra (be) is a coal mining company with mining business license (iup) of 1,199 ha and sk iup no. 08 / k / iup / xxvii / 2009. this company is a company engaged in mining and trading with consumers such as power generation and briquette industry. pt buana eltra undertakes material reduction process at martapura coal processing unit with installed concatenation is komatsu pc-300 excavator and gaperoll crusher which has been arranged with size of 10 cm. the increasing need for coal makes pt buana eltra's production target increase from 2,800 tons per day to 3,000 tons per day with a fixed coal demand requirement of 5-10 cm. the increase in production targets author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.1.1-62 makes the concatenation performance of crushing plant production system which is currently installed is considered less effective even though the production target is achieved, as seen from the increase of operational time and the increasing of operational cost which is not according to what is expected by the company so pt buana eltra needs evaluation re-concatenation of crushing plant production system. based on the above, it is necessary to evaluate the concatenation planning of production system in martapura coal processing unit which then conducted the study using analytic hierarchi process (ahp) method. this method is a simple method of analysis to make decision of concatenation of production system based on qualitative and quantitative data to get more optimal result [1]. 2. experimental section 2.1. study of literature the literature study was conducted by looking for literature studies related to crushing plant productivity issues, feeding tools (excavators), journals related to analytic hierarchy process (ahp) methods to assist in solving problems in this regard to determine appropriate concatenation of production systems. literature is a library materials, then from the library at the department of mining engineering sriwijaya university in the form of previous research reports, as well as from books books related to mining science. the productivity of the excavator can be calculated using the following formula [2]. tp = kb ×bf ×3600 ×fk ct (1) where: tp = estimated production (bcm/hour) kb = bucket capacity (m3) bf = bucket factor sf = swell factor fk = correction factor fk = efficiency of tools × work efficiency × operator efficiency ct = cycle time (seconds) the feeder is a material feeder tool from the hopper to the crusher unit at a constant speed [3]. the feeder capacity for feeding material to the crushing plant can be calculated using the formula: [4] q = v x t x l x d x 60 (2) where: q = feeder capacity (ton hour) v = hauling speed of feeder (m/min) t = height of material above feeder (m) l = feeder width (m) d = density of loos material (ton/m3) the evaluation using the analytic hierarchy process (ahp) method is a superior method for choosing competing activities or many alternatives based on specific or specific criteria [1]. these criteria can be qualitative or quantitative by using a tree model. this decision support model will describe complex multi-factor or multi-criteria problems into a hierarchy [5]. 2.2 field orientation field orientation activities are conducted by directly observing the coal reduction activities in the martapura coal processing unit of pt buana eltra as well as seeking supporting information and related to the issues discussed. 2.3 data collection the data collection in this research is divided into two types, namely primary data and secondary data. the data are as follows: primary data primary data obtained by observing the actual conditions in the field, interviews with supervisors and other employees. the primary data required are as follows : criteria concatenation of pc-300 and dimension 10 cm concatenation of pc-200 and dimension 10 cm concatenation of pc-200 and dimension 5 cm alternative ahp productivity operational time ahp ahp operational cost selection of concatenation crushing plant production system goal concatenation of pc-300 and dimension 5 cm figure 1 : ahp flow chart author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.1.1-63 a. the number of material entered in the hooper. b. cycle time excavator. c. fragmentation of dust (dust) on material. d. interview with experts on concatenation of production systems to meet ahp data. secondary data secondary data obtained from the literature or reference of previous research, secondary data required are as follows: e. specification of the tool used is from cat handbook and grobal dca three generating set. f. variables used as a correction factor in the calculation of productivity gained from reference books for mechanical soil removal as well as processing of resources and energy. g. the operational needs of existing equipment in the martapura coal processing unit. 2.4 processing and analysis of data the obtained data is then sorted, then calculated and presented in the form of ahp flow chart and table (figure 1). flow chart that has been made further filled with the desired criteria such as productivity, operational time, operational costs and then create alternativeconcatenation production system to be evaluated in this case excavator and dimension roll crusher. the desired criteria can be obtained by interviewing the experts by asking questions of the priority scale required for the ahp method (table 1) and determining the priority scale (table 2). the next step is calculates the cycle time data of each machine obtained by direct observation and then combines it into the ahp matrix calculation which can then be drawn the conclusion of the desired tools. data that have been processed subsequently collected each tool and criteria so that it can be known difference based on aspect productivity, operational time and operational cost yangselanjutnyadihitung using matrix to know the preferred order of tools to be selected. 3. results and discussion the evaluation of production system planning is done to optimize the production result from the crushing plant by doing assessment between several plans from concatenation of production system which enable to be applied and then to make decision using analytic hierarchy process (ahp) method to obtain the most effective technical and economical product extracting system. concatenation is a combination of a series of production systems between excavators with crusher roll dimensions on the crushing plant which is the equipment available in the martapura coal processing unit pt. buana eltra. the ahp method is used in analyzing and making the best decisions [6], including in the selection of concatenation. the main advantage of ahp methods is its ability to handle complex and ill-structured problems which cannot be usuallyhandled by rigorous mathematical models [7]. assessment of each concatenation crushing plant in the martapura coal processing unit is required before performing an ahp. 3.1 concatenation of actual crushing plant production system the processing of coal is one of the stages of mining activities. stages of coal processing are done to reduce the size of coal in accordance with the needs of consumers. pt. buana eltra in this case using crushingplant with crusher type of roll crusher that is set in accordance with existing technical studies. feeding in concatenation of its processing is done by utilizing excavator. roll crusher machine is suitable when used on a fragile material and moist, such as coal, gypsum, phosfate, clay, and others [8]. based on observations made at the martapura coal processing unit of pt buana eltra, the concatenation used today is considered to be less efficient and effective. concatenation is currently used using a combination of komatsu pc-300 excavator and roller gamer roll crusher dimensions that are set to 10 cm. concatenation has a productivity of 145,6701 tons / hour of operational time for 20.59447801 hours to get 3000 target per day and requires operational cost of rp 6.576.946 per hour. 3.2 alternative concatenation of crushing plant production system the small productivity of the concatenation currently being put into consideration to evaluate concatenation planning both currently available and enabling it to be applied. the concatenation of the product system includes concatenation between komatsu pc-300 excavator and 10 cm roll crusher excavator, komatsu pc-200 excavator roll crusher 10 cm dimension, komatsu pc200 excavator 5-cm roll crusher and komatsu pc-300 excavator dimensional roll crusher 5 cm. 3.2.1 concatenation of excavator komatsu pc-200 and roll table 1 : list of experts' inquiries no question priority scale answer 1 2 3 4 5 6 7 8 9 1 which is more important between productivity and operational time ? 2 which is more important between productivity and operational cost ? 3 which is more important between operational time and operational cost ? table 2. priority scale scale importance 1 equal importance 3 slightly more importance 5 materially more importance 7 significantly moreimportance 9 absolutely moreimportance 2,4,6,8 compromise values author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.1.1-64 crusher dimensions 10 cm this concatenation uses the komatsu pc-200 excavator and is combined with the dimensions of roller guser crusher 10 cm apart. concatenation has a productivity of 207,8468,722 tons / hour of operational time for 14.43370289 hours and requires an operational cost of rp 3,970,907 per hour. 3.2.2 concatenation of excavator komatsu pc-200 and roll crusher dimensions 5 cm this concatenation uses the komatsu pc-200 excavator and combined with the roller gape roll crusher dimension of 5 cm. concatenation has a productivity of 178.5756581 ton / hour operating time for 16.7996021 hours and requires an operational cost of rp 2,356,350. 3.2.3 concatenation of excavator komatsu pc-300 and roll crusher dimensions 5 cm this concatenation is a combination of komatsu pc-300 excavator and combined with the dimensions of gape roll crusher 5 cm apart. concatenation has a productivity of 178,237,7587 tons / hour of operational time for 16.83145043 hours and requires an operational cost of rp 5,375,205. 3.3 evaluation of concatenation selection planning using analytic hierarchy process (ahp) method the calculation of the technical and economical study of each concatenation is done to give the alternative weight value of each concatenation where the alternative weight consists of productivity, operational time and operational cost of each concatenation. the value of each concatenation must be adjusted to meet the requirements for evaluation using analytic hierarchy process (ahp) .the adjustment is a reduction to the maximum availability limit value of an alternative weights value obtained. based on the adjustment, we get the ahp weighting value from each concatenation of production system such as (table 3). 3.3.1 criteria weighting the criteria weighting is done by interviewing experienced experts or supervisors on the criteria used in the selection of concatenation of the production system, then assessing the specified criteria to be selected in the coal processing process. based on interviews and processing done based on ahp method is like table 4. 3.3.2 alternative weighting alternative weighting is done by distributing the value of each alternative concatenation to the total alternative value, so as to obtain a value arrangement such as hierarchy in figure 3. based on the stratified diagram (figure 3), the decision can be taken by multiplying the alternative matrix with the matrix of the criterion, such decisions (table 5) conclusion concatenation installed now is a combination of komatsu pc300 excavator roll crusher dimension 10 cm with productivity of 145,6701 tons / hour, operating time for 20,5944 hours and operational cost of rp. 6,576,946 per hour. based on observations at the martapura coal processing unit, several alternative concatenation production systems that can be used in crushing plant operation are komatsu pc-200 excavator-dimensional roll crusher 10 cm, komatsu pc-200 excavator 5 cm roll crusher and komatsu excavator pc-300 dimension roll crusher 5 cm.. selection of concatenation of production system based on ahp method with criteria of productivity, operational time and table 3. comparison of any concatenation after ahp adjustment no concatenation of crushing plant production system criteria productivity ahp (ton / hour) operating time ahp (hour / 3000 ton) operational cost ahp (rp. / hour) 1 excavator komatsu pc-300 and roll crusher dimensions 10 cm 1,456,701 34,055 3.423.054 2 excavator komatsu pc-200 and roll crusher dimensions 10 cm 2,078,469 95,663 6.029.093 3 excavator komatsu pc-200 and roll crusher dimensions 5 cm 1,785,757 72,004 7.643.650 4 excavator komatsu pc-300 and roll crusher dimensions 5 cm 1,782,378 71,685 4.624.795 table 4. pairwise comparison result of selection concatenation criteria item produktivity operational time operational cost weight produktivity 10,000 60,000 40,000 0,7096 operational time 0,1667 10,000 20,000 0,1354 operational cost 0,2500 0,5000 10,000 0,1550 belt conveyor double roll crusher alternative excavator hooper alternative dimension belt conveyor figure 2. concatenation scheme of crushing plant production system author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.1.1-65 operational cost resulted in optimum weight machine that is concatenation excavator komatsu pc-200-dimension roll crusher 10 cm. comparison of concatenation of production system currently used is komatsu pc-300 excavator 10 cm roll crusher dimension with engineering selection of concatenation based on ahp far enough and feasible to be replaced such as productivity concatenation excavator komatsu pc-300 dimension roll crusher 10 cm for 145,6701 tons / hour while the komatsu pc-200 dimensional roll crusher concretation 10 cm by 207,8469 tons / hour. the concatenation time is 20.5944 hours while the selected concatenation is 14.4337 hours and the current operational cost is rp 6,576,946, while the concatenation is rp 3,970,907. references [1] marimin. (2015). teknik dan aplikasi pengambilan keputusan kriteria majemuk. gramedia widiasarana indonesia. [2] tenriajeng, a. t., (2003). pemindahan tanah mekanis. jakarta: publisher gunadarma [3] harahap, a.i, iskandar, h, arief, t. 2014. kajian kominusi limestone pada area penambangan pt. semen padan (persero) tbk. bukit karang putih indarung sumatera barat. engineering journal of universitas sriwijaya, volume 2. no. 2. [4] currie, j. m. (1973). unit operation in mineral processing csm press columbia selection of concatenation crushing plant production system ahp produktivitity [0,7096] ahp operational time [0,1354] ahp operational cost [0,1550]  excavator komatsu pc-300 and roll crusher dimensions 10 cm [0,2051]  excavator komatsu pc-200 and roll crusher dimensions 10 cm [0,2926]  excavator komatsu pc-200 and roll crusher dimensions 5 cm [0,2514]  excavator komatsu pc-300 and roll crusher dimensions 5 cm [0,2509]  excavator komatsu pc-300 and roll crusher dimensions 10 cm [0,1246]  excavator komatsu pc-200 and roll crusher dimensions 10 cm [0,3499]  excavator komatsu pc-200 and roll crusher dimensions 5 cm [0,2634]  excavator komatsu pc-300 and roll crusher dimensions 5 cm [0,2622]  excavator komatsu pc-300 and roll crusher dimensions 10 cm [0,1576]  excavator komatsu pc-200 and roll crusher dimensions 10 cm [0,2776]  excavator komatsu pc-200 and roll crusher dimensions 5 cm [0,3519]  excavator komatsu pc-300 and roll crusher dimensions 5 cm [0,2129] figure 3. final result of all weighting table 5. decision table no alternative final value ranking 1 excavator komatsu pc-300 and roll crusher dimensions 10 cm 0,186814675 4 2 excavator komatsu pc-200 and roll crusher dimensions 10 cm 0,298032151 1 3 excavator komatsu pc-200 and roll crusher dimensions 5 cm 0,268594252 2 4 excavator komatsu pc-300 and roll crusher dimensions 5 cm 0,246558922 3 table 6. comparison of actual concatenation with best concatenation based on ahp method criteria actual concatenation best concatenation based on ahp method produktivity (ton / hour) 1,456,701 2,078,469 operational time (hour) 205,944 144,337 operational cost (rupiah / hour) 6.576.946 3.970.907 weigth ahp value 0,186814675 0,298032151 author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.1.1-66 [5] saaty, t. l. (1993). pengambilan keputusan bagi para pemimpin, proses hirarki analitik untuk pengambilan keputusan dalam situasi yang kompleks. pustaka binama pressindo. [6] yusuf, b. (2008). strategi kebijakan reklamasi lahan pasca penambangan pt. aneka tambang tbk unit bisnis pertambangan nikel daerah operasi maluku utara. journal of institut pertanian bogor [7] jamshidi, m. ataei, m. (2009). the application of ahp approach to selection of optimum underground mining methods, case study : jajarm bauxite mine (iran). journal of shahrood university of technology iran, volume 54. no. 1 [8] wills, b. a. dan tim, j. n. m. (2006). mineral processing technology edition: an introduction to the practical aspects of ore treatment and mineral recovery. australia : elsevier science and technology books. title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper composting system improvement by life cycle assessment approach on community composting of agricultural and agro industrial wastes rizki aziz1*, panalee chevakidagarn2, somtip danteravanich3, 1faculty of engineering, universitas andalas, kampus limau manis, padang, 25163, indonesia 2faculty of environmental management, prince of songkla university, hat yai campus, hat yai, 90112, thailand 3faculty of science and industrial technology, prince of songkla university, surat thani campus, surat thani, 84100, thailand *corresponding author e-mail: rizkiaziz@ft.unand.ac.id abstract in order to improve a community composting system, three scenarios have set based on the critical points of initial system from sensitivity analysis result of life cycle assessment of community composting system of agricultural and agro industrial wastes composting. sensitivity analysis of initial system revealed two critical points that used as consideration on setting of improvement system scenarios. on initial system, composting process contributed the highest impact potency on acidification, eutrophication, global warming, and photochemical oxidation, while distribution was responsible for the highest impact on human toxicity potential. by comparison of initial composting system with three improvement scenarios, it found that the third improvement scenario (sc3) was the best scenario that recommended to be implemented. sc3 promoted application of compost blanket for gases emission reduction of compost pile, and substitution diesel fuel of pick-up with cng fuel for transportation emission reduction. this scenario reduced impact of initial composting system by 29% with the highest impact reduction was on global warming potential by 54%. keywords life cycle assessment, composting system, agricultural and agro industrial wastes, sensitivity analysis, improvement scenarios received: 18 july 2018, accepted: 2 august 2018 https://doi.org/10.26554/ijems.2018.3.3.69-75 1. introduction composting has been applied as basic method to treat, minimize, and utilize organic wastes that produced by municipality, agricultural and agro industrial activity, because of its simplicity and cheapness. it produces compost which is safe and beneficial to apply for land and more environmentally friendly than chemical fertilizer (andersen et al., 2012). in thailand, application of composting has been introduced to the communities in order to increase their participation on providing organic compost for their own needs, as well as to improve their income through composting plant development program (siriwong et al., 2009; aziz et al., 2012). composting plant treats animal manures as the main material for composting such as cow dung, chicken, swine, duck and bat manures, besides palm oil mill waste, rice mill, and rubber wood manufacturing wastes (chevakidagarn et al., 2013). operation of these composting plants can reduce waste generation of agricultural and agro industrial activities such as rice plantation, sugarcane, corn, cassava, oil palm, rubber, soybean, mug bean and peanut bean (dede, 2012), and from animal farming such as cow manures, buffalo, chicken, pig and duck farming on provinces of nakhon si thamarat, phatthalung, surat thani, and songkhla (sridang et al., 2013). performance evaluation of community composting plants in southern thailand revealed that composting plant was facing problem on low efficiency of composting technique, and improvement of composting technology was recommended to be done (siriwong et al., 2013) application of life cycle assessment (lca) has been introduced in last decade due to assessing impact of composting system on the environment (komilis and ham, 2004; cadena et al., 2009; andersen et al., 2010; colón et al., 2010; martı́nezblanco et al., 2010; rigamonti et al., 2010). the studies investigated various composting methods such as windrows, tunnels, static pile, and composter. previous studies was concerned on organic fraction of municipal solid wastes as pruning waste, yard waste, organic household waste, garden waste, and left over raw fruits and vegetables. it concluded that composting process impacted the environment through global warming, acidification, https://doi.org/10.26554/ijems.2018.3.3.69-75 rizki aziz et. al. indonesian journal of environmental management and sustainability, 3 (2018) 69-75 photochemical oxidation, eutrophication, ozone depletion and human toxicity impacts (andersen et al., 2012; cadena et al., 2009; martı́nez-blanco et al., 2010). lca has also been applied in comparing composting method due to system improvement (lundie and peters, 2005; liamsanguan and gheewala, 2008; martı́nez-blanco et al., 2009; van haaren et al., 2010; boldrin et al., 2011; aziz and chevakidagarn, 2016). in comparing composting systems some improvements that recommended such as improvement of purities of being composted wastes and reduction of gaseous emission by gas treatment (cadena et al., 2009), transportation distance arrangement (martı́nez-blanco et al., 2010), and fuel fossil substitution (andersen et al., 2010). in order to study the composting technique that practiced on community composting and its impact to the environment, lca study was done on community composting of agricultural and agro industrial waste. by considering some improvements that recommended by aziz and chevakidagarn (2016), this study aims to find the better improvement scenario in order to improve the initial composting system of agricultural and agro industrial wastes. 2. experimental section 2.1 investigated composting system studied composting plant is located on rattaphum district in songkhla province, southern part of thailand. composting system consisted of feedstock collection, composting process which included electricity consumption and transfer material onsite plant, and distribution of compost product to customer. on composting process, agricultural and agro industrial wastes (aww) is mixed with phosphate rock and bio-activator mixture before being fermented for 20 days. aww contains with agricultural wastes which consists of goat manure, chicken manure, and bat manure, and agro industrial wastes consists of rice husk, rice bran, and decanter cake. bio-activator mixture is made up with molasses, liquid fertilizer, and seed from government to produce powder compost. composting process applies static pile method with intermittent aeration, with no leachate produced and no air emission reduction technology applied. compost products quality has been certified and could be applied for fruit farming and oil palm and rubber plantation. figure 1 configured diagram of related phases in the composting systems. 2.2 life cycle assessment lca defines as a method to assess the impacts of a product, process or service throughout the product’s life cycle into the environment that includes from raw materials acquisition to disposal of the product at the end of its life (unep/setac, 2009). lca has four phases; goal and scope definition; inventory analysis; impact assessment; and interpretation. analysis of environmental impacts of initial composting system and scenarios of system improvements was performed by software simapro v.7.3.0 (preconsultants, 2012). figure 1. flowchart of studied composting system figure 2. comparison of composting system scenarios in the first step, goal and scope were defined. goal of this study is to find a better composting system by comparing initial composting system that composted agricultural and agro industrial wastes with other improvement scenarios. the study scoped on comparing initial composting system that produced powder compost and three improvement scenarios based on reduction of composting gaseous emission, and substitution of fossil fuel to alternative fuels consists of biodiesel 5% (b5), liquefied petroleum gas (lpg) and compressed natural gas (cng). the functional unit (fu) is management of 1 ton of aaw to gain compost. system boundary of the study includes of collection of feedstock, composting process and distribution of compost to customers. otherwise, impact of material handling, fabrication of transportation vehicles, composting station, and related equipment were out of concern of this study due to the impacts were not related directly to the operation of composting system. allocation procedure is related to production process of composting that treated base on mass of compost produced, environmental burden of waste only related to dumped waste referred to cut-off method (ekvall et al., 1998). on the second step, inventory analysis, data of initial system were collected from related study by aziz and chevakidagarn (2016). meanwhile, data for improvement scenarios were collected from references related to application of compost blanket as gaseous emission reduction (ciwmb, 2007; utami et al., © 2018 the authors. page 70 of 75 rizki aziz et. al. indonesian journal of environmental management and sustainability, 3 (2018) 69-75 table 1. inventory of initial composting system phases items volume unit input collection truck and pick up van 64.08 tkm composting feedstock aaw 1,000.00 kg phosphate rock 142.39 kg bio-activator mixture 6.98 kg water consumption water 98.38 kg electricity mixer, conveyor, blower, crusher, sewing machine 5.72 kwh transfer material mini tractor 0.18 tkm distribution truck and pick up van 148.05 tkm output gaseous emissions ch4 0.49 kg nh3 1.54 kg n20 0.15 kg compost product compost 987.03 kg packaging 4.01 kg waste total 4.92 kg dumped plastic (bag, rope, packaging) 0.66 kg reused plastic (bag, rope) 4.24 kg recycled cardboard 0.02 kg source: [19] table 2. impact characterization result of initial system impact unit/fu total c co d ap kg so2 eq. 2.643 0.063 2.471 0.109 % 100 2.400 93.470 4.130 ep kg po4 −3 eq. 0.582 0.015 0.541 0.026 % 100 2.640 92.820 4.540 gwp kg co2 eq. 102.740 16.642 57.501 28.597 % 100 16.200 55.970 27.830 htp kg 1,4-db eq. 0.557 0.144 0.165 0.248 % 100 25.890 29.620 44.490 pop kg c2h4 0.005 0.001 0.003 0.001 % 100 15.590 57.620 26.790 note: c: collection, co: composting, d: distribution 2012), and gaseous emission from biodiesel b5, lpg and cng consumption on transportation (tgo, 2013). impact assessment as the third step was conducted by using the cml 2 baseline 2000 method that developed by centre of environmental science of leiden university (martı́nez-blanco et al., 2010). impact categories considered categories that have selected on related studies (cadena et al., 2009; martı́nez-blanco et al., 2010) which included abiotic depletion potential (adp), acidification potential (ap), eutrophication potential (ep), global warming potential (gwp), ozone depletion potential (odp), human toxicity potential (htp), and photochemical oxidation potential (pop). finally on interpretation step, the interpretation of initial system was followed by sensitivity analysis. it was done to find critical points to be considered as system improvement spots. all improvement scenarios then were compared in order to find the best scenario to be applied for system improvement. the best scenario was the scenario that has higher impacts reduction in comparison with initial system and more applicable with less consequences of economic and technology impact. moreover, the best scenario was compared with initial composting system to observe detail impact reduction that occurred. © 2018 the authors. page 71 of 75 rizki aziz et. al. indonesian journal of environmental management and sustainability, 3 (2018) 69-75 table 3. sensitivity analysis scenarios impact initial sensitivity analysis scenarios (%) category (%) sa1 sa2 sa3 sa4 sa5 ap 100 100 77 53 99.7 100 ep 100 100 77 54 100 100 gwp 100 100 87 75 99.98 93 htp 100 99.997 93 86 99.9 100 pop 100 99.999 86 72 94 100 impact initial sensitivity analysis scenarios (%) category (%) sa6 sa7 sa8 sa9 sa10 ap 100 100 100 100 99 98 ep 100 100 100 100 99 98 gwp 100 86 99.98 99.97 100 100 htp 100 100 100 100 89 79 pop 100 100 95 90 100 100 impact initial sensitivity analysis scenarios (%) category (%) sa11 sa12 sa13 sa14 ap 100 99.89 99.89 99.999 99.997 ep 100 99.9 99.9 99.998 99.997 gwp 100 98 98 99.99 99.98 htp 100 99.1 99.1 99.99 99.97 pop 100 99 99 99.99 99.98 3. results and discussion 3.1 initial composting system on initial system, data collected on inventory analysis showed in table 1. it depicted that in providing feedstock of 1 ton to be composted aaw took 64.26 tkm on collection phase. composting process input were 1 ton aaw, 142.39 kg phosphate rock, 6.98 kg bio-activator mixture (consisted of molasses, fluid bio fertilizer, and seeds), consumed 98.38 kg water, 5.72 kwh electricity for machineries, and 0.18 tkm on transferring material onsite plant. on distributing compost to customers 148.05 tkm was needed. meanwhile composting process emitted gaseous consisted of methane, dinitrogen monoxide, and ammonia. composting process was also generated wastes which later recycled, reused, and the rest were dumped and burnt. data inventory of initial system were classified and characterized for environmental impact assessment. cml 2 baseline 2000 method was used, and no discussion was performed about adp and odp impact categories due to no impact from present study on these categories. impact on environmental of each steps of initial composting system was summarized in table 2. it can be seen that higher sensitivity was shown on the change of gaseous emission quantity from composting process and transportation activities. reduction of gaseous emission (sa2 and sa3) were significantly reduced environmental impacts on ap, ep, gwp, htp and pop which exceeded 47%, 46%, 25%, 14% and 28%, respectively by 50% emission reduction. meanwhile, on gaseous emission reduction on transportation activities (sa4 to sa10) reduction all emission of ch4 and so2 (sa4) only reduce 6% of impact of pop, 0.3% of ap, and 0.1% of htp. reduction of co2 (sa5 and sa6) and co (sa7 and sa8) emission by 50% could reduce impact on gwp and pop by 14% and 10%, respectively, while reduction of n2o emission (sa9 and sa10) by 50% could reduce impact on htp by 21%. otherwise, sensitivity analysis (sa11 to sa14) shows that efficiency on electricity consumption (sa11 and sa12) by 50% were not sensitively reduced environmental impact, similar condition concluded from reduction of transfer material distance onsite plant (sa13 and sa14). it revealed that improvement of composting system could be performed by application of gaseous emission reduction from composting process and transportation activities. 3.2 improvement analysis based on sensitivity analysis result, improvement scenarios were developed in order to find the better system, three scenarios were introduced with improvement options by considering: a) better operation on composting gaseous emission reduction by choosing the application of compost blanket on the surface area of composting pile, refers to utami et al. (2012) and ciwmb (2007), this application could reduce emission of methane and dinitrogen monoxide up to 70% and 75%, respectively; and b) reduction of gaseous emission from transportation by shifting types of fuel consumed, based on emission factor that issued by tgo (2013), three alternatives of fuels including biodiesel b5, lpg and cng were selected as pick up van fuel with consideration of com© 2018 the authors. page 72 of 75 rizki aziz et. al. indonesian journal of environmental management and sustainability, 3 (2018) 69-75 table 4. impact characterization of improvement scenarios system impact unit/fu initial sc1 sc2 sc3 ap kg so2 eq. 2.643 2.643 2.557 2.56 ep kg po4 −3 eq. 0.582 0.582 0.562 0.562 gwp kg co2 eq. 102.74 62.286 47.256 47.121 htp kg 1,4-db eq. 0.557 0.559 0.366 0.371 pop kg c2h4 0.005 0.003 0.007 0.002 figure 3. impact comparison of initial system and improvement scenarios mercially provision of fuel. comparison of initial system and improvement scenarios was shown on figure 2. first scenario (sc1) considered application of compost blanket; and shifting of fuel of pick-up van on collection and distribution by using biodiesel b5, and pick-up truck use diesel. scenario 2 (sc2) applied improvement through shifting of fuel of pick-up van as collection and distribution vehicle with lpg. and scenario 3 (sc3) applied shifting of fuel of pick-up van into cng fuel. comparison of impact of initial and improvement scenarios showed on table 4 and figure 3. table 4 and figure 3 revealed that all improvement scenarios were contributed lower impact than initial system, except for impact category ap, ep and htp on sc1 and pop category on sc2. higher impact on category of ap, ep and htp were attributed by consumption of biodiesel b5 that emitted more no2 to the environment than diesel. higher impact on pop category was contributed by emission of co of lpg fuel that higher than diesel fuel. sc3 showed impact reduction on all impact categories with the higher impact reduction was performed on gwp by 54% of initial impact. by comparing percentage of total impact reduction on figure 3, it could be concluded that sc3 was the best scenario of improvement. table 5 and figure 4 represented impact characterization results of sc3. in sc3 all sub systems were contributed to all impact categories, similar with initial composting system. composting process was responsible for the highest contribution to all figure 4. impact comparison of initial and sc3 composting system impact categories, except for pop which was supplied by distribution sub system. composting process was contributed 2.464 kg so2 eq./fu (96.26%), 0.539 kg po4 −3 eq./fu (95.87%) and 0.154 kg 1,4-db eq./fu (41.52%) of total impact on ap, ep and htp, respectively. distribution sub system was responsible for contribution of 19.815 kg co2 eq./fu (42.05%) and 0.001 kg c2h4/ fu (40.48%) of total impact on pop. in detail, in comparison with initial composting system (see table 2, table 5 and figure 4), it can be observed that all impacts reduction was occurred in all impact categories. impact reduction were contributed by collection, electricity and distribution sub systems in all impact categories, while composting process sub system was attributed impact reduction only on gwp and pop categories, and for other impact categories were similar with initial composting system as well as transfer sub system since no improvement option applied on it. © 2018 the authors. page 73 of 75 rizki aziz et. al. indonesian journal of environmental management and sustainability, 3 (2018) 69-75 table 5. impact characterization result of sc3 impact unit total c co d ap kg so2 eq. 2.55 0.025 2.471 0.064 (%) -100 -0.99 -96.51 -2.51 ep kg po4 −3 eq. 0.562 0.006 0.54 0.016 (%) -100 -1.12 -96.08 -2.8 gwp kg co2 eq. 47.121 9.164 18.142 19.815 (%) -100 -19.45 -38.5 -42.05 htp kg 1,4-db eq. 0.371 0.059 0.165 0.147 (%) -100 -15.83 -44.45 -39.72 pop kg c2h4 0.002 0.0004 0.0008 0.0008 (%) -100 -18.03 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plants nutrients in four provinces in the south of thailand. in proceeding of the 6th tsae international conference (tsae2013). pages 83–88 tgo (2013). emission factor of thai national lci database (in thai). thailand greenhouse gas management organization, thailand unep/setac (2009). guidelines for social life cycle assessment of product. unep/setac life cycle initiative, belgium utami, t. s., h. hermansyah, and m. nasikin (2012). biofiltration of nitrous oxide using cow-manure based compost as medium filter. journal of environmental protection, 03(07); 584–588 van haaren, r., n. j. themelis, and m. barlaz (2010). lca comparison of windrow composting of yard wastes with use as alternative daily cover (adc). waste management, 30(12); 2649–2656 © 2018 the authors. page 75 of 75 introduction experimental section investigated composting system life cycle assessment results and discussion initial composting system improvement analysis conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper technical analysis backfilling plans of integrated on post mining plan suganda1*, restu juniah22, djuki sudarmono2, 1mining engineering department, sriwijaya 2lecturer of mining engineering department, sriwijaya university *corresponding author e-mail: sugandakaisar@yahoo.co.id abstract based on minister of energy and mineral resources of the republic indonesia number 07 years 2014 on the reclamation and post mining, every mining industry must have post mining planning to obtain mining operation. the objectives of research to know the direction of mining, the volume of pile plan and the design of the embankment. pt samantaka batubara is one of the coal mining companies geographically located in riau province. the study refers to the direction of mining from the beginning of 2017 from the southwest side to the end of the mine in 2022 to the northeast. the volume of overburden material stockpiles planned for the post mining plan program is 2,500,850 lcm in the 1st in 2021 and 3,000,665 lcm periods of the 2nd in 2022 period. the backfilling design in this study follows the recommendation of geotechnical analysis with every 5 meter hump should be formed in a slope angle of 300, with the direction of the heap toward the east. period prior to entering the post mining program that is in 2017 the embankment forms the highest elevation of +83 whereas in 2018 to 2020 the highest elevation is flat at +63 elevation. entering the post mining period of the highest elevation plan established at +63 elevations in 2021 and 2022. keywords ministerial regulation, dump volume, design of backfilling received: 31 june 2018, accepted: 20 august 2018 https://doi.org/10.26554/ijems.2018.3.3.88-93 1. introduction humans need mining commodities to meet their daily needs such as motor vehicles, mobile phones, electronic equipment, and others. the mining industry is there to meet those needs. mining commodities in government regulation no. 23 of 2010 concern about the implementation of mineral and coal mining business activities comprising of radioactive minerals, metal minerals, nonmetallic minerals, rocks and coal. mining of mineral and coal is done to get the mining commodity through production operation (juniah, 2017). pt samantaka batubara is one of the coal mining company geographically located in kecamatan peranap (desa pauh ranap and gumanti), kecamatan batang peranap (desa punti kayu), kecamatan rakit kulim (desa talang durian cacar) kabupaten inhu, riau province. natural forest and coal resources provide economic benefits for forest areas. mining benefits arising from mining business activities for the state are a source of state revenue and foreign exchange earners. other benefits that arise are as a producer of industrial raw materials, facilities and infrastructure to be built, providers of employment, absorption of labor. the utilization of the coal’s natural resources by mine is exposed to forest areas in addition to obtaining such benefits, on the other hand causing environmental losses (juniah et al., 2017). the post mining plan requires a backfill cover material design using minescape software (msc, 2011). base into permen esdm ri number: 07 year 2014 attachment that activity of post-plan will start in 2 (two) years before age of mine ends that is year 2022 (esdm, 2014). the period of implementation of coal mining activities of pt samantaka batubara starts from year 2017 until year 2022. actual planning of backfilling hole of pt samantaka batubara long-term mining has not existed yet. the actual backfilling done by pt samantaka batubara in 2017 was 96.12% with a volume of 2,433,000 lcm stockpiles of overburden production of 2,531,000 bcm. while a number of overburden material production of 98,000 bcm stockpiled to the disposal outside pit. supporting theories used to support this research include the geometry of the embankment covering the size of the ladder, the width of the ladder, the height of the ladder, and the minimum level of length at the time of mining (indonesianto, 2000), the productivity of the loading and hauling tools, the productivity is the ratio of the whole resources used (input) with the result achieved (output) (rostiyanti, 2008). the basic principle of calculating the volume capacity of backfilling is by calculating the volume of the https://doi.org/10.26554/ijems.2018.3.3.88-93 suganda et. al. indonesian journal of environmental management and sustainability, 3 (2018) 88-93 pyramid is cut off (kennedy, 1989). the main theory used in this research is the design model of embankment using minescape software. the formula used in theoretically calculating the volume of backfilling piles: volume = 1 3 xh(a1 + a2 + √ a1.a2) (1) information: h = heap height a1 = area of dredge a2 = area of dredge peak the productivity of the loading and hauling tools became the most important part of this study, since the amount of material the stockpile as backfilling will be measured for achievement based on the level of the tool’s capability (prodjosumarto, 1995). backfilling method is a method used to extract the mine that has been taken in the form of overburden material and then dumped back into the open pit hole (setyawan, 2004). the above problem is the background for research on technical analysis of backfilling plan with minescape software. the formulation of the problem in this study includes how the drill direction design plan ends up to the post mining stage, the required stockpile volume for the backfilling plan for revegetation at the time of entering the post mining period, and how the material backfilling plan designs as it enters the post mining period. this study aims to determine the direction of the mining plan, to analyze the volume of material needed for the backfilling plan and to analyze the design of the overburden material in the backfilling plan integrated with the post mining plan of pt samantaka batubara. 2. experimental section the location of the research is located on the area of mining business license of pt samantaka batubara geographically located at kecamatan peranap (desa pauh ranap and gumanti), kecamatan batang peranap (desa punti kayu), kecamatan rakit kulim (desa talang durian cacar) kabupaten inhu, riau province. the research was conducted on december 10, 2017 until january 10, 2018 in the engineering division. research starts from the stages of literature study to obtain materials related to research conducted and conclusions from the results of research. this study was conducted to study and implement theories related to mining plans, calculation of production of heavy equipment to produce heap volume and embankment design. the source of this literature study comes from research-related journals, archives of pt samantaka batubara, mining service. field orientation is done by observing directly mining activities especially stripping overburden. files collected to obtain primary files and secondary files. the primary files was generated is by calculating the actual time of the loader equipment and the haulage, this calculation is done to get the time required of mechanical equipment in producing the overburden material to be used as the embankment material. extensive design of mine and mining openings by coordinating with engineering teams to get an overview of mining constraints and pile areas. the function of know the type of material in this study site was to determine the ability of the pile volume while the types of flora around the research area to know the original ecosystem prior to mining. secondary files are supporting from literature and company files supporting in research covering andal document of pt samantaka batubara, document of ijin pinjam pakai kawasan hutan (ippkh), result of public consultation with stakeholders, type and amount of loading and tooling tools transport, and type of mechanical equipment to be planned in post mining activities. files processing is performed on the overburden material production balance files which will be stockpiled to determine the backfilling technical plan, equipment productivity and emtable 1. total calculation of long-term production balance (yearly) based on reserves and iup period year 2016 2017 2018 2019 2020 2021 2022 total coal target (million ton) infra 0,411 0,502 0,500 0,500 0,500 0,508 2,922 ob target (million bcm) infra 2,531 3,000 3,000 3,000 3,000 3,000 17,531 inpit dump volume (million lcm) infra 2,431 2,500 2,500 3,000 2,500 3,000 15,931 outpit dump volume (million lcm) infra 0,100 0,500 0,500 0,500 1,600 open mine area (ha) infra 16,690 10,400 12,150 11,790 12,100 11,900 75,030 inpit dump area (ha) infra 16,690 10,400 12,150 11,790 12,100 11,900 75,030 outpit dump area (ha) infra 1,196 5.981 5.981 5.981 19,140 sr (stripping ratio) infra 6,200 6,000 6,000 6,000 6,000 6,000 6,033 © 2018 the authors. page 89 of 93 suganda et. al. indonesian journal of environmental management and sustainability, 3 (2018) 88-93 figure 1. map of mining and reclamation plan of pt samantaka batubara bankment design. backfilling plans are undertaken to produce a land-clearing plan to be replanted (revegetation) upon entering the post mining period. analysis filse is done by processing the files that has been taken by manual calculation using microsoft office excel based on the theory obtained from literature study and assisted using software software minescape. the analysis was carried out on a mine progress plan synchronized with the post mining plan using minescape software and microsoft office excel. the results of the analysis using the minescape software were analyzed again to find other variables that could affect the work efficiency in the post mining plan. 3. results and discussion the mining plan at pt samantaka batubara adjusts to the distribution of existing coal deposits within the production operation mining permit. the form of coal deposits starts from the southwest (the highest elevation / lowwall) to the lowest elevation of the northeast (the lowest elevation / highwall). the direction of the mining plan from start to finish is useful as a reference to the boundaries and areas to be backfilled. 3.1 mining direction the mining direction planned by pt samantaka batubara can be seen in figure 1. the beginning of mining in 2017 starts from the southwest side then in 2018 continues towards the northeast side, whereas in 2019 mining starts on the southeast side of the mine, and continuously towards the northeast year 2022. outpit dump disposal located in the northwest of the mining area with a distance of ± 1.2 km. the calculation of overburden production in the mining area of pt samantaka batubara was expressed in units bcm. therefore, to determine the production of the the material is used the figure 2. production target of 2017-2022 pt samantaka batubara development factor (swell factor). the calculation results of mechanical device production have included influential factors in the calculation such as time of distribution, bucket capacity and work efficiency. production of long-term (annual) mechanical tools operating on the mining front is listed in table 1. the appropriate amount of reserves mined by ± 25,000,000 tonnes, taking into account the target market, 500,000 tonnes with sr 6 in the 2nd year to post mining with the same level of production / flats can be explained in figure 2. the amount of overburden material volume to be backfilled ± 2,500,000 lcm first year to third and rises to ± 3,000,000 lcm annually to digging tool and the conveyance must be multiplied by post mining. figure 2 explains that the production target during the life of the 6-year mine from 2017 to 2022 has increased. the increase only occuss in 2017 until 2018 and then the amount of production become flat until 2022. the planned production amount is adjusted to the marketing target of pt samantaka batubara. the production target which is the reference in this research is the production plan in the last 2 (two) years of the mine. production target which become the reference in this research is table 2. the amount of overburden production in table 2 is known as ± 3,000,000 bcm (bank cubic meter) / year. the number of overburden volumes to be dumped at a former mine of 2,500,000 lcm (loose cubic meters) in 2021 and 3,000,000 lcm (loose cubic meters) in 2022. the production target is shown in figure 4. is the volume of embankment which will be the basic assumption in the implementation of the research. target given is the last 2 (two) years target before entering the post mining period. the embankment form is one of the parameters of post mining success, in order to revegetate activities. circulation time is the time that a mechanical device needs to perform certain activities from start to finish and ready to start again. the haul road condition, workplace conditions, the condition of the equipment itself, and also the loading pattern © 2018 the authors. page 90 of 93 suganda et. al. indonesian journal of environmental management and sustainability, 3 (2018) 88-93 table 2. results of long-term (yearly) production balance calculations for post mining plans year 2021 2022 total coal target (milion ton) 0.5 0.508 1.008 ob target (million bcm) 3 3 6 inpit dump volume (million lcm) 2.5 3 5.5 outpit dump volume (juta lcm) 0.5 0.5 open mine area (ha) 12.1 11.9 24 inpit dump area (ha) 12.1 11.9 24 outpit dump area(ha) 5.981 5.981 sr (stripping ratio) 6 6 6 figure 3. volume target backfilling 2017 2022 pt samantaka batubara figure 4. volume target of backfilling 2021-2022 pt samantaka batubara undertaken strongly influence the timing as shown in table 3. work efficiency is the time required by operators with mechanical tools for production activities. analysis of the effective work efficiency of each conveyance and available loading device can be done by determining the value of the availability of the loading and transport tool which is a function of working time, standby time, and repair time of a device. the availability of tools is one of the things that affect the productivity of the digging tool and the means of transport. the degree of willingness of mechanical means to produce in the overburden material mining activity at pt samantaka batubara can be used to determine whether the physical condition of the device is in a ready to use state, good mechanics and whether or not to be used for production can be judged by the willingness to use the tool. modeling this embankment form used software minescape. design of embankment used additional files obtained from the technical team of pt samantaka batubara both topography and mining design. planning of embankment design has several references such as forest area spatial layout, public consultation result, and recommendation of embankment slope. 3.2 design backfilling based on the dinas kehutanan of kabupaten indragiri hulu number: 522.3 / sekr-iv / 2012/378 dated april 18, 2012 regarding the confirmation of forest area status in the mining permit area of pt samantaka batubara. pt samantaka batubara is mostly located in the area of hutan produksi terbatas (hpt) and is under the permit of iuphhk-ti (ijin usaha pemanfaatan hasil hutan table 3. average cycle time of mechanic equipment no. mechanic equipment cycle time (minutes) distance (meter) 1 loader excavator pc 400 vs cwb 0.34 2 hauler dump truck nissan cwb 10.15 ± 1,500 © 2018 the authors. page 91 of 93 suganda et. al. indonesian journal of environmental management and sustainability, 3 (2018) 88-93 figure 5. design embankment (2017-2020) pre-post mining kayu pada hutan tanaman industri). the results of stakeholder consultation are known to be one of the reasons that led the community to support the project, and became the basic reference in backfilling. the community, represented by village officials around the mine, called for a post mining program aimed at replanting rubber trees. therefore, the form of backfilling plan is adjusted to the type of plants demanded by communities around the mine. implementation of post mining program, it is necessary to design the form of pile that is allocated to the ex-mining area. it is useful to provide the location of planting plants planned for revegetation. based on the recommended geotechnical shear angle in the recommended is 300 and each increase of embankment of 5 meters with a bench width of 5 meters. the rock characteristics used for the analysis of steepness of the embankment slope are 50% of the average residual cohesion (cr) and shear angle in the mean residual (dr) and 70% of the average saturated density value (ysat) and the water level the soil is considered to follow the height of the slope (the slope is saturated). the result of a single embankment slope analysis is considered to be steady if it has a fk greater than 1,300 and the overall slope of the heap with fk is greater than 1,500. the calculation of steepness slope stability is performed for each slope-forming material, using two parameter variations, namely: high slope (m): 5, 10, 15, and 20; and angle of slope (0): 30, 45, 50, 60, 70, 80. the morphological form of the research area, especially those included in the first-stage licensing under the ippkh document (permit for use of forest areas), tends to enter hilly areas and figure 6. design embankment (year 2021) backfilling year-1st still in the green zone (suwarna et al., 1991). the backfill shown in figure 5 is a form of embankment that has been implemented before entering the post mining period (2 years before the mine’s life). in the present study, the peak elevation of the embankment plan must be considered, because when mining is no longer operational, the water entering the mine is designed to be removed without pumping. modeling this embankment form used software minescape. design of embankment using additional files was obtained from the technical team of pt samantaka batubara both topography and mining design. figure 6 is an embankment design in the first year of the post mining plan period, showing that the intensive hoarding direction is heading east with the highest elevation target of the embankment +63. the highest elevation is a safe elevation of the puddle, so the plant is not eroded or waterlogged when the mine is no longer active. the shape of the embankment at the end of the post mining in figure 7 is averaged +63 elevation, while on the southwest side of the iup (mining business license) which is mining in 2017 the peak of the embankment is at +83 elevation. the embankment design is tailored to the planned post mining plan, so that post mining activities can be effective and efficient. the highest elevation target on the embankment design is intended to allow the water into the mining area to be exhausted overflow. 4. conclusions the design of the backfilling form based on the geotechnical recommendation of pt samantaka batubara every 5 meter increments of heap must be formed in a slope angle of 300, with the direction of the heap to the east. backfilling designs from © 2018 the authors. page 92 of 93 suganda et. al. indonesian journal of environmental management and sustainability, 3 (2018) 88-93 figure 7. final pile design (year 2022) backfilling year 2nd 2017-2020 (before entering the post mining program) the highest elevation of 2017 at elevations +83 and 2018 to 2020 are flat at +63 elevation, whereas in 2021 (the first post mining year) is at elevation +63 flats until the end of the mine in 2022. acknowledgement thanks to the management of pt samantaka batubara for the op¬portunity given to the author to conduct a research survey on the location of coal mining business license pt samantaka batubara. references esdm (2014). regulation of the minister energy and mineral resources number 07 year 2014 about the implementation of reclamation and post mining on mineral and coal mining business activities indonesianto, y. (2000). mechanical material movement. master’s thesis, upn veteran, yogyakarta juniah, r. (2017). technical review of post mining plan. indonesian journal of environmental management and sustainability; 1–9 juniah, r., r. dalimi, m. suparmoko, s. s. moersidik, and h. waristian (2017). environmental value losses as impacts of natural resources utilization of in coal open mining. matec web of conferences, 101; 04013 kennedy, b. a. (1989). society for mining, metallurgy, and exploration,surface mining 2nd edition. colorado school of mines: colorado msc (2011). open cut introductions and mine design minescape. mining software company pt mitrais prodjosumarto, p. (1995). mechanical material movement. mining departement institut teknologi bandung rostiyanti, s. f. (2008). heavy equipment for construction projects. rineka cipta, jakarta, indonesia setyawan, d. (2004). land character change on reclaimed coal mine reclaimed areas for one, two, three, and four years with sengon and akasia. department of soil science, faculty of agriculture ipb suwarna, m. slamet, s. raharja, satunggalno, b. lestari, i. sukarna, m, s. winarni, and prihadi (1991). geology regional map page rengat map. technical report, pusat penelitian dan pengembangan geologi (p3g), bandung, indonesia © 2018 the authors. page 93 of 93 introduction experimental section results and discussion mining direction design backfilling conclusions acknowledgement indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article doi: 10.26554/ijems.2017.1.1.6-106 received: 12 september 2017 accepted: 15 november 2017 *corresponding author email: restu_juniah@yahoo.co.id sustainable mining environment: technical review of post-mining plans restu juniah1,* 1mining engineering department, sriwijaya university abstract the mining industry exists because humans need mining commodities to meet their daily needs such as motor vehicles, mobile phones, electronic equipment and others. mining commodities as mentioned in government regulation no. 23 of 2010 on implementation of mineral and coal mining business activities are radioactive minerals, metal minerals, nonmetallic minerals, rocks and coal. mineral and coal mining is conducted to obtain the mining commodities through production operations. mining and coal mining companies have an obligation to ensure that the mining environment in particular after the post production operation or post mining continues. the survey research aims to examine technically the post-mining plan in coal mining of pt samantaka batubara in indragiri hulu regency of riau province towards the sustainability of the mining environment. the results indicate that the post-mining plan of pt samantaka batubara has met the technical aspects required in post mining planning for a sustainable mining environment. post ponement of post-mining land of pt samantaka batubara for garden and forest zone. the results of this study are expected to be useful and can be used by stakeholders, academics, researchers, practitioners and associations of mining, and the environment. keywords: post-mining plan, sustainable coal mining environment, technical aspects. 1. introduction natural resources of forest and coal provide economic benefits for forest areas. mining benefits arising from mining business activities for the state are a source of state revenue and foreign exchange earners. the other benefits are as a producer of raw materials for industry, construction of facilities and infrastructure, employment providers, absorption of labor. utilization of natural resources of coal by mine open in forest area to get the benefit, on the other side causing environmental losses [1]. nations and countries wanting the conservation of natural resources must implement environmentally sound development. maintaining and sustaining the preservation of natural resources is necessary for the survival of human beings today, as well as for future generations. the relationship between the community, forest-forming plants, with the fauna and nature of the environment is very close and cannot stand alone so that the forest is seen as an ecosystem. this is because the destruction of the forest will damage the existing ecosystems in the forests and surrounding areas, as well as damage all living systems [2]. coal has calories that can be utilized for various purposes, including for industry, household and electric power generation. policies made by the central and local governments in riau province are the driving factors for the establishment of several business entities engaged in mining, including pt. samantaka batubara located in peranap and rakit kulim district, indragiri hulu regency riau province. the post-mining plan is an obligation that must be implemented by mineral and coal mining companies. the obligation to make the post-minater plan is regulated in government regulation no. 78 year 2010 on reclamation and post-mining, ministerial regulation no. 7 year 2014 on implementation of reclamation and post-mining plan on mineral and coal mining business activities. post-mining activities are defined as planned, systematic and continuous activities after the end of part or all of the mining business activities to restore the function of the natural environment and social functions throughout the mining area. therefor post-mining activities are carried out in order to improve or manage the use of disturbed land due to coal mining, in order to be functional and efficient in accordance with its allocation to keep the coal mining environment sustainable. post-mining activities of pt samantaka batubara through the post-mining land allotment are expected to restore the function of the forest as an ecosystem so that the forest as a natural resource remains sustainable and the coal mining environment remains sustainable. based on this it becomes an important point and becomes a force in this research to study the technical aspects of post-mining plan of pt samantaka batubara. 2. experimental section the research method used is survey by observing directly to the location of coal mining business license pt samantaka batubara. the analysis used descriptively to describe or describe how the initial hue conditions at the research location, so that can be mapped technically aspects of post-mining land titling pt samantaka coal. this awakening is for the sustainable return of the mining environment. data collection is done through collecting data in primary to get primary data, and secondary to get secondary data. primary data is obtained by direct observation, and secondary data is done by tracking literature study and instasional. research location of coal mining business license pt. samantaka batubara is located in the southeast of pekanbaru city in peranap subdistrict (pauh ranap & gumanti village), batang perjuniah, 2017 | indones. j. env. man. sus. 1 (1) 2017: 6-10 doi: 10.26554/ijems.2017.1.1.6-107 anap sub-district (punti kayu village), rakit kulim sub-district (talang durian cacar village) inhu regency of riau province. delivery of the territory can be reached by road from pekanbaru city towards peranap through the east cross road sumatra with a distance of approximately 200 km or travel for approximately 4 hours using the four wheel vehicle with paved road conditions. the location of research is shown in figure 1. 3. results and discussion the technical aspect is an important aspect besides the economic aspect in determining the post-mining land allocation. this is because the economic planning has in addition to having a very close relationship with the technical aspects also becomes the basis in determining the economic planning of the post-mining costs. the technical aspects discussed are as follows: 3.1. pleminery hue pleminery hue becomes fundamental in technical planning especially related to the return to post-mining land use function. allotment of former mining land is expected to restore the minimum as the initial hue before the activity. used land is a land that has been taken or carried out activities of mining commodities (minerals, coal and rocks) in the place or location. the initial tone is largely divided into geophysical groups of chemical biology, socio-economic, cultural, and public health. the pleminery hue in this study focused on the geophysical conditions associated with the soil and biology associated with the existing plant site site location. this emphasis is based on the results of previous research conducted by kusmana on coal mining pt arutmin indonesia site batulicin south kalimantan province. kusmana research finds if soil character effect on plant growth [4]. the influence of soil character in the kusmana et.al study area indicates if soil characteristics have caused stunted sengon and acacia plants used as test mediums. the test results found that sengon plants suffer from small dwarfs in most plots, whereas acacia plants are found only on a few plots. technical aspects such as soil analysis should / should be undertaken prior to reclamation and revegetation activities to determine treatment for soil properties improvement [5]. the largest soil type of coal mining area of pt samantaka batuabara is yellow red podsolic spread of eastern hills and red latosol in the west. this land has low fertility. this is related to the level of soil acidity, low nutrient, high clay content [6] . the tendency of the soils on the post-mining land of coal to be sour caused by pyrite minerals which is one of the compounds of coal minerals. the soil quality at the study site is influenced by land cover vegetation. based on a survey conducted showing some plants or vegetation cover in the location of coal mining pt samantaka is the dominant rubber garden and oil palm plantation. the visible forestry crops are jabon, rengas, meranti, pule, waru. other plants have bananas, areca nut and shrubs. vegetation of ground cover in coal mining pt samantaka batubara is shown figure 2. 3.2. mine design and mine age coal mining planning is aims to technically design coal mining activities such as mining methods, mining systems, mining design and mine life. based on these matters, it can be planned for post-mining land plots. the method used in pt samantaka batubara open pit (surface mine) with open cast mining system [7]. this selection is based on characteristics of available coal deposfigure 1. map location of pt. samantaka batubara [3] figure 2. uninterrupted area, disturbed land, reforestation and other utilization of mined land juniah, 2017 | indones. j. env. man. sus. 1 (1) 2017: 6-10 doi: 10.26554/ijems.2017.1.1.6-108 its and available technology. mine design of pt. samantaka batubara is designed with the following criteria: 1. the mine design plan is 26º with single slope 45o and fk> 1.3. this is based on the overall slope recommendation 2. a temporary mining design, following the limits of production forest and location topography. 3. mining blocks with geometry of 150 x 150 meters with a height of 5 meters level became the basis for making the mining schedule. 4. mining is done by cutting the hill up to an elevation of ± 150 meters above sea level, and for long-term mining it is possible to lower it at lower elevations by forming bench levels. 5. mining is done from the west to the eastern part. 6. the first work begins by establishing access roads to reach the top of the hill, further lowering the elevation to the height of the mining plan. 7. coal production capacity ± 1,000.000 tons / year for a total of 11,800,000 tons for seven years of mine life. based on the mineable reserves amount of ± 25,000,000 tons, taking into account the target market, in the first year coal mining amounted to ± 1,000,000 tons, and continues to increase every year, to reach the level of production in the year to 6 and 7 to 3,000.000 tons. 3.3. reclamation and allocation of post-mined land 3.3.1.mine reclamation the objectives of mine closure and impacts due to mine closure should be considered from an early stage of activities so that mining can contribute positively to sustainable development both economic, and social & environmental. therefore, mine closure planning should integrate these three aspects. characteristics of mineral and coal resources in indonesia are one of them characterized by the availability of most of the sediment in the layer of the earth near the surface of the soil. this leads to many mining methods that are open pit. use of this method can cause changes in landscape elements, including topography, vegetation cover, hydrological patterns, soil structure damage, and others. this condition can complicate the reclamation process. reclamation is needed to restore and restore the former land according to the purposes. mine reclamation is part of post-mining activities. approaching and technologies are needed in reclaiming ex-mining land. the approach and technology used will be different [8]. this depends on the nature of the disturbance that occurred and also the allocation (use after the reclamation process). reclamation is done by the following steps: top soil conservation; planting cover crop; planting of pioneer plants; countermeasures of heavy metals. area, mine used, greening, other utilization some types of mining enterprises in indonesia are presented in table 1. based on the above table it can be seen that until 2009 the disturbed land for mine and infrastructure area was only 78.81 ha from the total area of 2,205,348 ha, with reclaimed land of 31.209 ha. figure 2 shows the disturbed land used by coal mining activities until 2009 was only 3.6% of the total land. reforestation activities undertaken on degraded land of 1.4%, and by 0.11% for other uses. the overall of the entire disturbed land are 1.51% or 41.94%. this condition is actually not ideal if referring from the existing regulation of the minister of energy and mineral resources no. 07 of 2014 and pp ri no. 78 in 2010, reclamation no later than six months after mining commodity mining activities. the above indicates that if reclamation/revegetation activities and other utilization are done on mining land in accordance with the provisions of the law, then until the end of 2009 the percentage of reclamation / revegetation and other utilization will be equal to the disturbed land or at least 80%. based on one of the objectives of the mine reclamation activity is to restore the environmental function to the disturbed land, with the greater the percentage of reclamation and other utilization of disturbed land figure 3. postpartum phase diagram table 1. area, mine used land, reforestation, other utilization some types of mining enterprises in indonesia no type of business area land area disturbed (ha) greening (ha) other uses (ha) total (ha) (ha) 1 contract of work production stage 516,803.30 15,856.48 9,088.09 877.81 9,965.90 2 coal mining concession agreement production stage 825,862.60 36,988.63 15,077.32 735.3 15,812.62 3 mining rights exploitation 862,682.46 25,965.78 7,044.29 944.77 * 7,989.06 total 2,205,348.35 78,810.89 31,209.70 2,557.88 33,767.58 juniah, 2017 | indones. j. env. man. sus. 1 (1) 2017: 6-10 doi: 10.26554/ijems.2017.1.1.6-109 will further improve the environmental function returns so that the mining environment is more sustainable. uninterrupted areas, disturbed land, reforestation and other utilization of mine extracted land are shown in figure 2. 3.3.2. allotment of post mining land the challenge for sustainable natural and environmental sustainability in indonesia is one approach that can be used in natural resource management policies in sustainable development [9]. its implications in the mining sector are post-mining planning for a sustainable mining environment. post-mining stages for mineral, coal, nonmetallic and rock mining are conducted as shown in figure 3 [10]. based on the figure, post-mining land use is included in stage 1 in post-mining planning. postpartum planning is set forth in the post-mining plan document or known as the post mining plan document. post mine land clearance either from the various researches conducted by previous researchers as well as those contained in the post mining plan document aims to sustain the environment and the environment of sustainable mining. witoro has studied of coal mining of pt kaltim prima coal in east kutai regency of east kalimantan province, and found various ex-mining land uses with various scenarios for forests, for rubber gardens and oil palm plantations [11]. utilization of land used coal mine was implemented in pt. kaltim prima coal (kpc) east kutai regency, east kalimantan for agricultural land using sago plant with balanced fertilization [12]. dairah et.al [13] found the utilization of former mining land for plantation crops, cultivation of seasonal crops including paddy rice, and brown crops. utilization of post-mining land of pt adaro indonesia in tabalong district south kalimantan province was implemented for lakes, irrigation, clean water, electricity, fishery program, agriculture, livestock and plantation. yuniawatiningtyas [14] develops post-mining areas as an arboretum that conserves soil, water, and biodiversity especially local crop species. the concept was developed into the concept of space, circulation, activity and facilities and vegetation. natural resources that are affected by mining activities, in principle or action should be returned to safe and productive conditions through rehabilitation. the final condition of rehabilitation can be directed to achieve such conditions before being mined or other conditions agreed upon. rehabilitation aims to return the mine site to conditions that allow it to be used as a productive land. the determination of post-mining land use depends on various factors such as the ecological potential of the mine site and the wishes of the people and the government. formerly rehabilitated mining sites should be maintained to remain integrated with the surrounding landscape ecosystem. pt. samantaka batubara is committed to maximizing post-mining land titling and post-mining physical environment management in order to provide sustainable benefits not only for pt. samantaka batubara but also to people living around the mine and mining environment. post-mining land that used plan in pt. samantaka batubara based on forest license use permit in the designation into a garden zone with an area of 51.79 ha. the exploited mining area was originally a plantation and a shrub. for ex-mining land use coal exploitation activities in order to continue to provide economic benefits for local communities and local commodities in a sustainable manner, the restoration of ecosystems of ex-coal mining areas will mostly be allocated for sustainability of plantation products. therefore, the zoning of former mining land of pt. samantaka batubara is for the garden zone. this zone is an area that will be planted with local commodities, both from the vicinity of mining business license pt. samantaka batubara or bring in the seeds from outside. land allotment plan (coal end mine) coal mining pt. samantaka batubara is shown in figure 4. 4. conclusion postponement of post-mining land of pt samantaka batubara at the end of production operations is planned in order to restore environmental function and sustainable coal mining is for the garden zone. this is based on technical studies such as initial hue conditions, mine design and mine life, forest area license use permit with an area of 51.79 ha. acknowledgement thanks to the management of pt samantaka batubara for the opportunity given to the author to conduct a research survey on the location of coal mining business license pt samantaka batubara. references [1] juniah, r. dalimi, m. suparmoko, m. moersidik, s,s. and waristian. h. 2017. environmental value losses as impacts of natural resources utilization of in coal open mining. matec web of conferences. 10. pp 1-5, 2017. [2] juniah, r. environmental sustainability model of coal mining study value of environmental services, and water void mine for raw water in pt bukit asam tbk tanjung enim south sumatra. dissertation. environmental science program university of indonesia., jakarta, 2013 [3] coal mining company pt samantaka batubara. pt. samantaka batubara post mining plan. 2017. [4] c. kusmana, y. setiadi, and al-anshary, m,a,l. 2013. study of plant growth as a result of revegetation in coal ex-mined land pt. arutmin indonesia site batulicin south kalimantan. silvikultur tropika journal. 04, pp 160–165. [5] ministry of environment and forestry. post mine land reclamation: policy aspects, conservation and technology, procedure of research seminar results, 2013. [6] coal mining company pt samantaka batubara. pt. samantaka batubara environmental impact assessment. 2012. [7] coal mining company pt samantaka batubara. pt. samantaka batubara feasibility study. 2011. [8] dariah, a., abdurachman and subardja. d.a. 2010. reclafigure 4. land use plan (coal end mine) coal mining pt. samantaka batubara [3] juniah, 2017 | indones. j. env. man. sus. 1 (1) 2017: 6-10 doi: 10.26554/ijems.2017.1.1.6-1010 mation of ex-mining land for agricultural extensification. journal of land resources. 4. [9] juniah, r. and zakir. s. 2015. natural resources and management policy a challenge in sustainability. the 6th iuaes conferences. university of manchester, uk, 2015. [10] irsan, h. and mutiari. y.l.. post mine reclamation policy as a form of land used coal mine control viewed from authority of regional autonomy in south sumatera. faculty of law sriwijaya university. [11] soemarno. w.s. post-mining development planning to support sustainable development (case study on coal mining pt kaltim prima coal in east kutai district, east kalimantan province). dissertation. environmental science program, university of indonesia, jakarta, 2007. [12] mashud, n. and manaroinsong. e. 2014. utilization of coal mine for sago development. journal of palma, 15. pp 56–63. [13] coal mining company pt adaro indonesia. pt adaro indonesia mining closure plan. 2012. [14] yuniawatiningtyas. e. post-coal landscape planning as arboretum in white land area sebuku island, south kalimantan. essay. department of landscape architecture faculty of agriculture bogor agricultural university, 2014. title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper reclamation planning on mining operations pt. prima timah utama in mapur village, bangka regency, bangka belitung province imam firdaus1*, didik susetyo2, restu juniah3, 1postgraduate, magister of mining engineering, sriwijaya university, palembang 30139, indonesia 2professor, economic department, sriwijaya university, palembang 30139, indonesia 3associate professor, mining engineering department. sriwijaya university, palembang 30139, indonesia *corresponding author e-mail: imamfirdaus1@yahoo.co.id abstract pt. prima timah utama is one of the companies that received a production operation mining permit from the bangka regency government in may 2014. the company has been carrying out mining activities since mei 2014, with a maximum production level of 500,000 m3 of ore per year. this study made a field study of the impact of mining activities carried out by the company, looked at the success rate of reclamation, and calculated the ideal costs to improve environmental quality a�er mining activities. reclamation planning for mining operations at pt. prima timah utama is included in the type of non-experimental qualitative research conducted desktop study and field observations in the mining field. this research will analyze and make a reclamation plan based on the criteria of success of ex-mining land that is standard for sustainable mining. the results of the study show a lack of guarantee of the implementation of reclamation guaranteed by the company to the government of ± 50% of ideal conditions. based on the results of the study, the company will use plants that are able to have a high level of adaptation to critical environments. one type of plant chosen is acaciamangium. the costs needed to carry out the ideal reclamation activities to improve the quality of the environment a�er mining are idr 3,642,427,321.or idr 65,629,324./ hectare keywords tin, reclamation, reclamation guarantee, acaciamangium received: 4 september 2018, accepted: 5 october 2018 https://doi.org/10.26554/ijems.2018.2.4.98-101 1. introduction indonesia is a country which rich in mineral resources with one of them being tin. based on data released by the indonesia mining association in 2009, shows that tin content in indonesia is the second largest in the world (kristian, 2016).therefore, many companies are engaged in the tin mining industry, one of them is pt. prima timah utama in the province of bangka-belitung. each mining activity will have two sides, in the form of positive and negative impacts. the positive impact will arise in the form of improving the economy of the community around the mine due to the absorption of labor and the opportunity to open new jobs such as buying and selling services, and others. without denying the negative impacts will arise as a result of mining activities in the form of losses to the environment (juniah et al., 2016). environmental losses arising in the form of chemical, biological, and physical changes in the ex-mining land. therefore, according to adi et al. (2017) a planned reclamation activity is needed in an e�ort to overcome the negative impacts of activities. reclamation activities take place during the mining process to post-mining. the purpose of reclamation activities is to restore the environmental conditions of the former mining sites as before or to be more productive, so that it is expected to produce environmental and sustainable added values for the present and future generations according to their designation (munir and d, 2017; suparmoko, 2006). the biophysical, environmental, social and economic aspects of the community must be considered in carrying out reclamation activities in order to be able to reduce the negative impacts of tin mining (asmarhansyah and r, 2017). this is because the economic, social and environmental balance in the mining sector is a goal for achieving sustainable mining activities (juniah, 2018). juniah mentions, reclamation stages include topsoil conservation, cover crop planting, pioneering crop planting, heavy metal countermeasures (juniah, 2017). landscape changes that occur as a result of mining activities can be permanent (for example deep undersea soil, changes in soil bodies, and loss of biodiversity) or temporary (for example, dumps of remaining excavation and tailings), so that conducting reclamation activities requires di�erent approaches and technologies (dariah et al., 2010). https://doi.org/10.26554/ijems.2018.2.4.98-101 firdaus et. al. indonesian journal of environmental management and sustainability, 2 (2018) 98-101 pt prima timah utama as a company that conducts mining activities is obliged to carry out reclamation and post-mining activities as stipulated in government regulation no. 78 of 2010 and ministerial regulation no. 7 of 2014. reclamation activities are an act to organize, restore, and improve the environment so that it can function in accordance with its uses carried out throughout the mining business phase (esdm, 2014). pt prima timah utama in planning its reclamation activities will carry out revegetation activities with the selected plant species being acacia (acaciamangium). legislation related to mining requires mining companies to reclaim the mining business permit area that they seek. this reclamation activity can be carried out throughout the mining business phase and continues after the end of some or all activities. the company is required to deposit reclamation guarantees through joint accounts between the government and the company as a form of seriousness towards reclamation activities. reclamation guarantees must be placed before the company conducts production operations for the �rst �ve-year period, and continues for the next �ve years. determination of the components of reclamation costs refers to government regulation no. 78 of 2010, namely: (a) direct costs include costs for land administration, revegetation, prevention and control of acid mine drainage, civil works in accordance with the designation of post-mining land; and (b). indirect costs include the cost of mobilization and demobilization of equipment, reclamation planning, administration, and supervision. reclamation guarantees must be provided by holders of mining business permits and special mining business licenses consisting of a reclamation guarantee for the exploration phase and reclamation guarantee for the production operation stage. the obligation to implement reclamation activities by holders of mining business permits and special mining business licenses will not be lost despite the placement of reclamation guarantees to the government (pohan and anwar, 2014). the calculation of the amount of reclamation collateral for the planned reclamation activities must be calculated as accurately as possible aims to the planned reclamation plan can run well so that the sustainable environment expected by all parties can be achieved. 2. experimental section 2.1 materials administratively the location of the mining operation permit for the production operation is in the cit village of riau silip sub-district, bangka regency, bangka belitung province with the area of the mining business license, the production operation is 58.7 hectares. the prime mining business license area of pt prima timah utama can be reached by using twoor fourwheeled vehicles from the capital city of pangkal pinang for approximately 80 kilometers. the condition of road access using relatively good asphalt and yellow soil, provincial and district roads are concrete and asphalt road classes with a width of 4 meters, district road access that connects the location with the provincial road have a road width of 3 meters. figure 1. map of research location the data needed in this study are primary data and secondary data. primary data to be taken directly include: 1. initial condition for areas that have not been mined. 2. technical tin mining carried out by the company. 3. e�orts made by the company related to environmental protection 4. the success rate of reclamation results in the previous stage, measured by the percentage of success. 5. comparison between reclamation plans and actual conditions that include area, type of plant, growth rate, and others. 6. the amount of reclamation guarantees that has been submitted for the �rst �ve year period. secondary data needed, including: 1. company environmental studies which include analysis of environmental impactsdocuments, post-mining plans, and reclamation plans for the �rst �ve-year period. 2. documents or regulations related to reclamation success criteria. 3. evaluation report of the success of the �rst �ve-year reclamation stage 4. study results with relevant agencies including the o�ce of energy and mineral resources of bangka regency and bangka belitung province. 2.2 method reclamation planning for mining operations at pt. prima timah utama is included in the type of non-experimental qualitative research conducted on a desktop study basis and �eld observations in the mining sector. this research will analyze and make a reclamation plan based on the criteria of success of ex-mining land that is ideal for sustainable mining. © 2018 the authors. page 99 of 101 firdaus et. al. indonesian journal of environmental management and sustainability, 2 (2018) 98-101 3. results and discussion 3.1 initial environmental scope the initial environmental tone is a description of the state of the environment around the location of the planned activity. based on observations in the �eld, the type of vegetation found around the location of the activity is generally secondary forest area and scrub vegetation. the types of fauna found in the location around the activity are still found in many types of birds including pipit, punai, perbak, tekukur, kutilang, and others. reptile animals found around the planned activity location based on �eld survey observations and community information are snakes, lizards and monitor lizards. while the types of mammals that are found around the location include civets, bats, and pigs. residents around the mine site consist of malays, palembang, javanese, and ethnic chinese with a majority islamic religion and a small percentage of christians, buddhists, and confucians. 3.2 mining system mining activities in the production operation mining permit area of pt. prima timah utama uses an open-pit mining system where mining uses a combination of loading equipment, conveyance equipment, and mine pumps to obtain dry tin sand with sn content of 70-74%. the following is the actual and planned ore production from pt. prima timah utama from the estimated total reserves of 3,300,000 m3. table 1. plans and actual production of pt. prima timah utama period 2014 2018 no year production actual plan (m3) production (m3) 1 2014 350,000 321,200 2 2015 500,000 487,500 3 2016 500,000 497,320 4 2017 500,000 486,211 5 2018 500,000 total 2,350,000 1,792,231 3.3 reclamation activities ex-mine land pt. prima timah utama has been reclaimed using a pot system, which contains a mixture of topsoil, the chemical fertilizer and compost fertilizer. the selection of plants for revegetation must consider several aspects including the suitability of plants to the land, ease of maintenance, availability of seeds, quality of crops produced and economic aspects. the choice of plant species for revegetation was chosen by acacia plants (acaciamangium). this type of plant, including the type of plants that grow around the mining business permit other than that, is a type of plant with rapid plant growth. the cropping pattern used in this revegetation uses a square pattern and alternating planting between other plants and acacia. the pattern is intended for competition in �nding nutrients between plants. 3.4 calculation of reclamation guarantee costs calculation of reclamation guarantee costs is divided into direct costs and indirect costs. direct costs consist of land management costs, revegetation costs, post-mining civil works costs, and maintenance costs. based on the calculation of direct costs for pt prima timah utama reclamation activities in 2014-2018 idr 2,914,653,977.-. the amount of indirect costs which consist of the cost of mobilization and demobilization of heavy equipment, reclamation planning, administration and supervision costs is idr 1,211,531,064. so the total reclamation costs that must be guaranteed by the company based on the calculation for the �rst 5 (�ve) yearsis idr 3,642,427,321.-. 3.5 comparison of reclamation guarantees after recalculation, there is a lack of guarantee for the implementation of reclamation guaranteed by the company to the government. the di�erence is seen in table 2. the above conditions can be compared by looking at the amount of reclamation costs or guarantees issued by the company. the cost calculation is an amount with a percentage of ± 50% of the ideal condition. pt prima timah utama has compiled documents and deposited reclamation guarantees for the period 2014 2018. the reclamation guarantee that has been paid in that period is idr 1,847,871,160.-. this amount is still ± 50% of the results of the calculation of this study. this study has calculated the additional funds needed by the company to improve the quality of the environment, the additional amount is idr 1,794,556,340.-. the additional funds are expected to make the environment that was previously a mining activity area to increase the quality of the environment after reclamation compared to the initial hue. 4. conclusions pt. prima timah utama has made reclamation e�orts in the period 2014 2017 with a success rate of ± 50% of the target. the company in an e�ort to improve the quality of the environment after the mine will carry out revegetation activities using acaciamangium trees. the ideal reclamation guarantee for pt. prima timah utama based on the results of the calculation is idr 3,642,427,321, or as much as idr 65,629,324, -/hectare. 5. acknowledgment thanks to the management of pt prima timah utama for the op¬portunity given to the author to conduct a research survey on the location of tin mining business license pt prima timah utama. references adi, andi, i. nurul, s. w. y, wirdaningsi, and n. a (2017). reclamation analysis of the limestone mine in bungoro district, pangkep regency, south sulawesi province. geomine journal, 5(2); 68–75 © 2018 the authors. page 100 of 101 firdaus et. al. indonesian journal of environmental management and sustainability, 2 (2018) 98-101 table 2. comparison of reclamation guarantees no. year company guarantee calculation guarantee di�erence (idr) (idr) (idr) 1 2014 341,433,640 415,877,100 -74,443,460 2 2015 222,617,807 346,053,000 -123,435,193 3 2016 513,403,925 292,965,300 220,438,625 4 2017 191,350,482 307,384,100 -116,033,618 5 2018 579,065,306 2,280,148,000 -1,701,082,694 total 1,847,871,160 3,642,427,500 -1,794,556,340 asmarhansyah and h. r (2017). reclamation of former tin mine land as agricultural land in bangka belitung islands. proceedings of the national seminar on location-speci�c agroinnovation for food security in the era of the asean economic community; 881–892 dariah, a., a. abdurachman, and d. subardja (2010). reclamation of ex-mining land for agricultural extensi�cation. journal of land resources, 4(1) esdm (2014). ministerial regulation no. 7 of 2014 concerning reclamation plans and post-mining plans. jakarta. juniah, r. (2017). sustainable mining environment: technical review of post-mining plans. indonesian journal of environmental management and sustainability, 1(1); 6–10 juniah, r. (2018). study of carbon value of the allotment of former coal mining land of pt samantaka batubara for sustainable mining environment. journal of sustainable development, 11(4); 213– 227 juniah, r., r. dalimi, m. suparmoko, s. moersidik, s, and harrywaristian (2016). environmental value losses as impacts of natural resources utilization of in coal open mining. matecproceding scopus index; 1–5 kristian, r. (2016). implementation of reclamation and postmining obligations regarding mineral and coal mining in samarinda city based on government regulation number 78 of 2010. journal of law; 1–9 munir, m. and s. d, n (2017). study of post-mining land reclamation in jambi, bangka, and south kalimantan. klorofil, 1(1); 11–16 pohan and c. anwar (2014). reserves for mining reclamation as tax loopholes in implementing the principles of taxabilitydeductibility. scienti�c journal of administrative sciences, 6(2); 181–198 suparmoko, m. (2006). guide & analysis of economic valuation of natural and environmental resources: concepts, calculation methods, and applications. first edition. bpfe yogyakarta © 2018 the authors. page 101 of 101 introduction experimental section materials method results and discussion initial environmental scope mining system reclamation activities calculation of reclamation guarantee costs comparison of reclamation guarantees conclusions acknowledgment title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper the noise level in residential areas bordering jagorawi highway evelyne hanaseta n1*, lidia handayani1, yega serlina2 1environmental engineering programme, faculty of engineering, universitas sahid jakarta, jakarta, 031030, indonesia 2environmental engineering programme, faculty of engineering, universitas andalas, padang, 25163, indonesia *corresponding author e-mail: evelyn hanaseta@usahid.ac.id abstract noise pollution has not become a priority in environmental issues, but the potential negative impact on society based on studies can be in the form of physical and psychological disturbances, the main cause of noise in the urban area is transportation. identification of noise sources needs should be done to ensure that the sound produced accordance with environmental characteristics. the jagorawi toll road is the 3rd density toll road in the jabodetabek area, compared to several other toll roads. jagorawi toll road is bordered by residential areas. in the cibubur-cimanggis sector, this toll road is directly adjacent to residential areas with a distance of < 20 meters and some points do not have barriers to reduce noise. the cibubur-cimanggis sector is currently developing with the addition of the lrt, which will operate in 2022 so that current noise measurements can be used as baseline data at the study site. this noise monitoring is intended to conclude whether or not there is an effect of noise felt by the surrounding community from activities on the jagorawi toll road and to obtain a reduction in noise levels using a single barrier with a height of 0.5, 1, 1.5 and 2 m. noise monitoring is carried out using sni 8421:2017 for 24 hours at 2 measurement points in residential areas. point one and point two each have a noise value (lsm) of 68.87 and 61.29 dba with a correlation value of 0.605 (medium). the noise value has exceeded the quality standard for residential designation based on the minister of environment decree no. 48 of 1996 (55 dba), so a barrier is needed to reduce the noise received by the community. the analysis of the use of the barrier studied is a single barrier with g = 1. as the result of adding a barrier at point 1 with high 2 m, the noise value can be reduced by 16.7 dba with a p-value of 0.00, so the addition of a barrier has a significant impact on the noise value. this study found the effect of noise from the jagorawi toll road up to a distance of 114 m at a point that does not use a barrier, so the role of the barrier along the toll road is very important. with the use of a barrier, the distance required to reduce single noise originating from the toll road to < 55 dba is 20 m. keywords noise level, jagorawi highway, residential area, barrier received: 25 february 2022, accepted: 19 may 2022 https://doi.org/10.26554/ijems.2022.6.2.53-58 1. introduction noise in the environment has become an old issue that has not received public attention and concern, even since 2009 a noise study has been compiled which shows that 96% of residential areas and settlements in big cities in indonesia have exceeded the quality standard of 55 dba. noise problems also have an impact on physiological and psychological disorders, some of the impacts include disturbances, sleep disturbances, hearing problems, hypertension, etc. this effect is influenced by the length of time of exposure (passchier-vermeer and passchier, 2000; ba and kang, 2019). noise monitoring and handling activities in indonesia have not yet experienced significant developments regarding the minister of environment decree no. 48 of 1996. noise pollution in big cities is generally caused by traffic compared to other sources, urban development also increases urban noise levels with more activities resulting in more vehicle use (kuldeep and mathur, 2020). the characteristics of the location (activities around the location, especially the types of transportation available, the use of public transportation cars and motorbikes) will affect the noise measurement results (syaiful and wahid, 2020). studies on noise complaints show that population density also affects the number of complaints, the denser an area is, the higher the complaints about noise (tong and kang, 2021). the noise level every year can continue to increase along with the growth in the number of vehicles. noise disturbance in urban areas is dominated by transportation sources from roads, trains, and planes so in the predictive analysis of the combination of transportation types it is necessary to consider (marquis-favre et al., 2021). this also affects the https://doi.org/10.26554/ijems.2022.6.2.53-58 nurakbari et. al. indonesian journal of environmental management and sustainability, 6 (2022) 53-58 noise level of residential and residential areas around toll roads, where there is an increase in the noise value of residential areas around the toll road by 12.5% from an increase in the number of vehicles by 10% (çolakkadıoğlu and yücel, 2017). the city of depok as a buffer for the dki jakarta area has a population growth of 15.5% from 2010-2020 (statistik, 2021). depok city has access to various modes of land transportation, this continues to be developed including public transportation modes and road network improvements so that it becomes an attraction for people to choose a location to live (kadarisman et al., 2016). the rapid development of transportation facilities in buffer cities around dki jakarta provides comfort for the community, but without realizing it will affect the normal life of the community with the development around it, so noise prevention measures are needed (liang et al., 2022). the jabodetabek toll road is a toll road in the jabodetabek area with traffic of 123,029,004 vehicles in 2020, this value is ranked third for toll roads in the jabodetabek area (statistik, 2021). jagorawi has a road length of 46 km so in some sectors, it is directly adjacent to settlements. previous research in residential areas in bogor showed that at a distance of 50 m from the jagorawi toll road the noise value was 56.10 dba, above the quality standard of minister of environment decree no. 46 of 1996. in addition, there are previous studies on the potential for noise from the jagorawi toll road with the addition of a natural barrier (plants) with a thickness of 8 m to reduce noise by 10 dba. noise barrier can reduce 9.98 10.47 dba from the highway depending on the distance and height of the barrier used so that in terms of noise mitigation, optimization of the barrier can be done (sahraei and ghaemi, 2013). residential areas have a higher sensitivity to noise, especially at night (lm) because the housing area has a function to rest for its residents while other areas don’t have. in addition, the effect caused by noise pollution is to cause sleep disturbances, interfere with speech, and can affect performance (elfaig et al., 2014). the use of natural barriers (trees) and artificial barriers have a significantly reduced value from noise sources, so trees or artificial barriers in urban areas will become an important part of the considerations in urban planning (zhao et al., 2021). the purpose of this study was to determine the noise level of the residential area around the jagorawi highway and to determine the effect of noise reduction using a single barrier. 2. experimental section 2.1 research location harjamukti village is located on the east side of the cimanggis sub-district, this village is directly adjacent to the provin ce of dki jakarta, bogor regency, and bekasi city. harjamukti village has a population of 23,269 people with a population density of 3,931 people/km2 in 2019 (statistik, 2021). harjamukti village is the only sub-district in cimanggis which borders the jagorawi toll road. in addition, the harjamukti village has access to lrt transportation with the harjamukti lrt station which will operate in 2022. in this study, the measurement locations were carried out at 2 points, point 1 at s06022’54.60” and e106053’43.80” with a distance of 20 meters from the jagorawi toll road, while point 2 at s06022’47.50” and e106053’32.10” with a distance of 114 meters from the jagorawi toll road. more detailed information about the location can be seen in figure 1. figure 1. research location 2.2 noise measurement based on sni 8427:2017, environmental noise level measurement is carried out using an integrating sound level meter that meets the requirements of applicable national and/or international standards. however, for steady noise, where the noise has a constant average characteristic over time (fluctuation limit of 5 dba), measurements can be represented by a minimum of 7 data. the time of taking the 7 data are as follows: 1. sample 1 was picked up at 07:00 representing 06:00 – 09:00 2. sample 2 was picked up at 10:00 representing 09:00 – 14:00 3. sample 3 was picked up at 15:00 representing 14:00 – 17:00 4. sample 4 was picked up at 20:00 representing 17:00 – 22:00 5. sample 5 was picked up at 23:00 representing 22:00 – 24:00 6. sample 6 was picked up at 01:00 representing 24:00 – 03:00 7. sample 7 was picked up at 04:00 representing 03:00 – 06:00 after the measurement data is obtained, calculations can be made to obtain pressure level in 10 minutes of measurement or regular noise in a certain period (laeq) using equation 1, the environmental noise level at day level (ls) can be calculated using the equation 2, night level (lm), and night level (lsm) can be calculated using equation 3. ls is the laeq value during the day (16 hours) from 06:00 – © 2022 the authors. page 54 of 58 nurakbari et. al. indonesian journal of environmental management and sustainability, 6 (2022) 53-58 22:00, lm is the laeq value during the day (8 hours) from 22:00 – 06:00, while lsm is the average noise level for 24 hours. meanwhile, based on sni 8427:2017, the formula for calculating the noise level is as follows: laeq = 10 log 1 n n∑ i=1 = 100.1lidba (1) ls = 10 log 1 16 (t110 0.1l1 + t210 0.1l2 + t310 0.1l3 + t410 0.1l4 ) ls = 10 log 1 8 (t510 0.1l5 + t610 0.1l6 + t710 0.1l7 ) (2) note: t1 = 3; t2 = 5; t3 = 3; t4 = 5; t5 = 2; t6 = 3; dan t7 = 3 lsm = 10 log 1 24 (16 x100.1ls + 8 x100.1(lm+5)) (3) 2.3 noise analysis of distance and noise attenuation variation noise has a different pattern with or without the use of barriers. to ensure the significance level of the use of the barrier, a simulation of the use of the barrier is carried out at point 1 and the resulting noise dilution pattern is carried out up to point 2. sound moves through the propagation medium until it reaches the receiver, in its spatial movement the sound experiences a dilution which can generally be written in equation 4 (sutherland, 2000): lp(r2) = lp(r1) − 20 log 10( r2 r1 ) (4) where: lp(r1) = known sound pressure level at the first location; lp(r2) = unknown sound pressure level at the second location location; r1 = distance from the noise source to the location of known sound pressure level; r2 = distance from the noise source to the second location. the use of a barrier as an effort to mitigate noise is carried out by using a concrete wall barrier, this is done by considering the location adjacent to the jagorawi toll bridge so that the use of natural barriers is not possible. the barrier is placed to block the acoustic propagation so that there is a change in the length of propagation (δ) besides the wavelength (λ). a = √ c21 + (h − s)2 (5) b = √ c22 + (h − r)2 (6) c = √ (c1 + c 2 2 ) + (r − s)2 (7) δ = a + b c (8) research on road attenuation was conducted by kumar et al. (2014) using fresnel numbers (n) and the mekawa method using graphs. in addition to using graphs, noise reduction can be calculated according to equation (7) according to the obtained fresnel value. fresnel value (n) is a dimensionless number to predict the noise attenuation perceived by the receiver. n = 2δ λ (9) ∆b = 10 log [( 1 ϕr−ϕl )( 1 √ 10 )(∫ ϕr ϕl tanh2 √ 2πncosϕ 2πncosϕ dϕ )] (10) the research was conducted by measuring the noise level compared to the quality standard of the minister of environment decree no. 46 of 1999 concerning noise. furthermore, the noise barrier design is carried out with variations in height to get noise attenuation according to noise reduction needs. the results of the discussion will show the optimum barrier height required according to the noise level. the research flow chart can be seen more fully in figure 2. 3. results and discussion 3.1 noise measurement the research location consists of 2 points, point 1 is 20 meters away and point 2 is 114 meters from the jagorawi toll road. identification of noise sources is carried out by observation and interviews, the results of the identification of the two methods the noise sources consist of the jagorawi toll road and local roads. based on direct observation, the noise source around the research location is transportation from jagorawi toll road and local road, but based on community interviews at point 1 87.5% came from traffic noise and 12.5% came from horns and exhaust noise, while at point 2 there was the influence of community activities by 37.5%, traffic noise 50% and horns and exhaust noises 12.5%. research in other residential areas shows similar results from finding sources of outdoor noise in residential areas which are generally caused by traffic, construction, environmental activities, and weather. in this study, the very noisy category is found at point 1, while point 2 is included in the noisy and slightly noisy category. this is also in line with the lsm value aimed at point 1, which is 68.87 dba while point 2 is 61.29 dba. the distribution of noise data at both locations can be seen in figure 3. based on the ministry of environment decree no. 48 of 1996, the measurement results show that location 1 (68.87 dba) is included in the quality standard for trade and service and © 2022 the authors. page 55 of 58 nurakbari et. al. indonesian journal of environmental management and sustainability, 6 (2022) 53-58 figure 2. research flowchart industrial areas of 70 dba, while location 2 (62.77 dba) is included in the quality standard for office areas of 65 dba, so that the area under noise level research is not suitable for use as a residential area (55 dba). figure 3. noise measurement results for each location it can be seen in figure 3 that the noise level between 06.00 17.00 tends to be higher than the noise level at 22.00 03.00. this is influenced by human activities which are more active during the day, this is also in line with previous research that the noise level during the day tends to be higher than at night ls > lm (çolakkadıoğlu and yücel, 2017). the measurement results obtained that the ls values at points 1 and 2 were 69.9 and 62.77 dba. while the lm values at points 1 and 2 are 60.52 and 49.05 dba. spatially a decrease in noise concerning the distance from the noise source occurs, this decrease can be seen from the comparison of the values of lsm, ls, and lm at points 1 and 2. spatial reduction of noise sources can occur due to reduced sound energy due to the distance of propagation, this also occurs in residential areas close to the urban expressway in the shapingba district with a negative correlation value between distance and noise level with a p-value <0.01 (li and xie, 2021). the statistical description of the data is displayed in the form of l10, l50, and l90. the l10 values at locations 1 and 2 were 71.6 and 64.7 dba. the l50 values at locations 1 and 2 were 65.6 and 55.4 dba. the l90 values at locations 1 and 2 were 57.2 and 45.8 dba. at point 1 the lsm value is between l50 and l10, this result illustrates that the noise value at that location tends to be consistent and can be associated with a noise source in the form of the jagorawi toll road which operates for 24 hours. while point 2 has an lsm value that is close to the l10 value, this contribution can be caused by sensitivity to peak activities or shortduration noise around the location. in spatially measuring noise, roads with high density have a characteristic lsm value that is close to the l50 value, while on a low-density road it has an lsm value close to l50 and l10 (dirgawati et al., 2021). figure 4. correlation of location noise values location 1 and 2 sample locations 1 and 2 had the same treatment during data collection and analysis so the interpretation used correlation r = 0.8 and the value of determination was 0.676. the value of determination can describe the relationship between © 2022 the authors. page 56 of 58 nurakbari et. al. indonesian journal of environmental management and sustainability, 6 (2022) 53-58 table 1. noise attenuation h (m) n ∆b (dba) received noise 1 0.279 11.699 57.170 1.5 1.443 12.992 55.877 2 4.803 16.726 52.143 2.5 9.306 21.729 47.140 3 14.366 27.351 41.518 the independent variables (point 1) and can explain 68% of the value of the dependent variable (point 2) with a positive correlation. while the results of the kolmogorov-smirnov normality test (n = 70) showed a sig value >0.05, meaning that both data were normally distributed. in addition, the analysis of mean differences t-test shows a value of sig <0.05, the test results show the influence of noise at location 2 from noise at location 1 (jagorawi highway). the value of determination or correlation at several different points can be caused by the same noise source but still has other noise sources as the influence of each location (dirgawati et al., 2021). 3.2 noise attenuation the results of the noise measurement at point 1 with a radius of 20 m from the jagorawi toll road have exceeded the quality standard. the position of the border which is a bridge requires a noise barrier in the form of a wall to reduce the noise received by the community (settlement). noise mitigation design is planned in several variations of barrier height to get the noise reduction value to reach the required quality standard. while the distance variation is not carried out because the border area between the jagorawi toll road and the settlement has been built. to find out the difference between the use of barriers and the use of barriers, a mathematical model is calculated according to equation 8 and 9. the barrier usage function was analyzed in a mathematical model assuming the use of a barrier with reflected effect. the purpose of reflection is to think about the sound energy that will be received by the receiver (gagliano et al., 2020). so that the noise reduction resulting from the variation of the barrier height can be seen in table 1. in table 1 the height of the noise source used is 1 m and the height of the receiver is 2 m. while the fresnel value is the value obtained from the calculation of the path traversed by the sound divided by the wavelength. then this fresnel value is associated with noise reduction which can be found using equation 10 or the meikawa graph. the use of barriers in several previous studies has been shown to reduce noise statistically significantly (ba and kang, 2019). noise reduction due to the use of barriers can be influenced by the height of the barrier and the distance between the noise source and the noise receiver (iordache and ionita, 2018). figure 5. effect of barrier height on noise reduction based on figure 5, to achieve a noise level of 55 dba (according to residential designation), a barrier with a height of 2 m is required, so that the noise level will be reduced to 52.143 dba. in general, increasing the height of the barrier under the same conditions will reduce noise even more (positive correlation) (kumar et al., 2014). this positive correlation is also found in the calculation of the use of a barrier with a high variation in figure 5 with a determination value of 0.956. however, the use of a barrier that is too high can reduce the aesthetic value so that it is necessary to adjust the distance at a location that has a high noise level and is less than optimal in the use of the barrier. 4. conclusions in residential areas around jagorawi highway has a value above the quality standard for residential areas (lsm > 55 dba). residential areas have values that are influenced by transportation activities on the jagorawi highway. the source of noise owned by residential areas is transportation, but in settlements with a distance of > 100 m, it is identified that there are sources of noise from human activities. based on noise reduction analysis, with current conditions it is necessary to use a barrier as high as 2 m so that the noise level is < 55 dba. 5. acknowledgment the author would like to thank lppm sahid university jakarta for the internal grants provided for this article. the author also thanks to mr. iwan prasetiyo, st., mt., ph.d (lecturer physics engineering, itb) for the opportunity to share about environmental noise. © 2022 the authors. page 57 of 58 nurakbari et. al. indonesian journal of environmental management and sustainability, 6 (2022) 53-58 references ba, m. and j. kang (2019). effect of a fragrant tree on the perception of traffic noise. building and environment, 156; 147–155 çolakkadıoğlu, d. and m. yücel (2017). modeling of tarsus adana gaziantep highway induced noise pollution with in the scope of adana city and estimated the affected population. applied acoustics, 115; 158–165 dirgawati, m., g. n. apriani, a. a. asyari, and r. triyogo (2021). traffic related noise at roadside schools: assessment and prediction in urban setting. jurnal teknologi lingkungan, 22(2); 178–189 elfaig, a. h., m. duad, n. m. adam, m. bardaie, and r. abdullah (2014). monitored community noise pollution in selected sensitive areas of kuala lumpur. international journal of scientific and technology research, 3(2); 2277– 8616 gagliano, a., f. nocera, a. cicero, l. marletta, and g. evola (2020). mitigation of environmental noise in urban streets through lightweight transparent screens. noise mapping, 7(1); 57–73 iordache, v. and m. v. ionita (2018). urban sound energy reduction by means of sound barriers. in e3s web of conferences kadarisman, m., a. gunawan, and i. ismiyati (2016). kebijakan manajemen transportasi darat dan dampaknya terhadap perekonomian masyarakat di kota depok. jurnal manajemen transportasi & logistik, 3(1); 41–58 (in indonesia) kuldeep, s. s. and a. mathur (2020). comparative assessment of noise models for kota city. in materials today, 513; 5619–5625 kumar, k., m. parida, and v. katiyar (2014). optimized height of noise barrier for non-urban highway using artificial neural network. 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(2000). overview of outdoor sound propagation. in 29th international congress and exhibition on noise control engineering. pages 27–30 syaiful, s. and n. wahid (2020). a study of the density of motor vehicles in front of bunda hospital margonda depok against noise pollution. the spirit of society journal, 3(2); 110–132 tong, h. and j. kang (2021). relationship between noise complaints and urban density across cities of different levels of density: a crowd-sourced big data analysis. the lancet, 398; s86 zhao, n., j. f. prieur, y. liu, d. kneeshaw, e. m. lapointe, a. paquette, k. zinszer, j. dupras, p. j. villeneuve, and d. g. rainham (2021). tree characteristics and environmental noise in complex urban settings: a case study from montreal, canada. environmental research, 202; 111887 © 2022 the authors. page 58 of 58 introduction experimental section research location noise measurement noise analysis of distance and noise attenuation variation results and discussion noise measurement noise attenuation conclusions acknowledgment indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article doi: 10.26554/ijems.2017.1.1.19-2219 received: 10 september 2017 accepted: 7 november 2017 *corresponding author email: reniarisanti07@gmail.com study of the effect of coal quality parameters on gas methane (ch4) emission in coal fire for sustainable environment reni arisanti 1,*, maulana yusuf1, m. faisal2 1mining engineering departement, sriwijaya university, palembang 30139, indonesia 2chemical engineering departement, sriwijaya university, palembang 30139, indonesia abstract coal is formation media of methane gas which retains the ability to store gas in large quantities. methane gas (ch4) one of the greenhouse gases that its existence can be troubling, because the gas can increase the impact of global warming, the can damage the ozone layer and increase the temperature of the earth. methane gas (ch4) emissions occurred in the coal combustion process were strongly influenced by the physical and chemical of coal. this research was intended to know how the influence of quality parameters and calorific value of coal methane gas (ch4) emission, and temperature in combustion process. this research is quantitative research with method of quantitative descriptive and descriptive associative approach. average methane gas emissions (ch4) occurring for each calorific value of coal calories: 3.98 ppm from 5900 kcal/kg, 1.30 ppm from 6300 kcal/kg, 0.26 ppm from 6700 kcal/ kg, and 0.08 ppm from 7600 kcal/kg. the relationship of temperature, calorific value and methane gas emission (ch4) is the higher the calorific value, the required temperature will be higher and the gas emission smaller: for the calories of 5900 kcal/kg, the average temperature was 63.75oc; 6300 kcal/kg, 60.92oc; 6700 kcal/kg, 52.59oc, and 7600 kcal/kg, 113.98oc, respectively. indonesian coal mostly consists of low rank coal which can cause high methane (ch4) emissions that would also cause problems to the environment. keywords: coal, methane, methane emissions, global warming 1. introduction coal is a formation medium of coal methane gas (cmg) has the ability to store gas in large quantities. this is because the surface of the coal has many pores smaller in size than the micron scale, causing the coal surface to absorb large amounts of gas. gas trapped in coal consists mostly of methane gas [1]. coal methane gas (cmg) is a methane gas (ch4) produced from natural processes that occur during the coal formation process. the gas will be formed biogenically due to decomposition by microorganisms producing methane and co2 gas [2]. methane gas (ch4) is one of the greenhouse gases that its existence can increase the temperature of the earth, because the gas can increase the impact of global warming (global warming) which will lead to a decrease in environmental quality. methane gas is the greenhouse gas emitting second place after co2 [3]. coal in indonesia lies in the boundary between sub bituminous and bituminous coal, but almost 59% is lignite [4]. pt. bukit asam (persero) tbk as one of the coal producer in 2016 total production is 19.69 million tons increased by 3% from 2015 by 19.29 million tons, while the production target pt. bukit asam (persero) tbk in 2017 increased again by 22% from 2016 that is 24.07 million tons, where most of the coal is low rank coal [5]. low rank coal has in the combustion process will result in higher gas methane (ch4) emissions compared to high calorie coal [6]. this can lead to an increase in the impact of global warming which will cause a decline in environmental quality. the scope of the problems in this study includes coal quality parameters, calorific value, gas methane (ch4) emissions, and the effect of temperature on the combustion process. this study aims to (1) analyze the effect of calorific value of coal on methane emissions (ch4), (2) calculate how much methane gas emission (ch4) occurs during coal combustion, (3) analyze the effect of temperature of methane gas emissions (ch4) during the combustion process. 2. experimental section 2.1.coal burning process coal is one type of fuel for energy generation. coal may also be used not as fuel, but is used as a reducing agent for tin smelting, ferro-nickel industry, iron and steel industry, as a purification agent in the chemical industry (in the form of activated carbon), as a calcium carbide (in the form of coke , or semi coke) [7]. the coal combustion process is a very quick reaction between coal and oxygen to produce the product. the requirements for perfect combustion according to are: (1) all carbon (c) contained in coal to co2 in the product; (2) all hydrogen (h) present in coal to h2o in the product; (3) all the sulfur (s) inside the coal is so2 in the product [8]. the coal-forming element consists mainly of carbon and hydrogen, so the carbon and hydrogen content will greatly determine the combustion process of coal. based on the calculation of the amount of air needed to burn various types of coal can be seen in table 1. 2.2.methane gas in coal methane gas is the simplest hydrocarbon compound in the form of a colorless gas and also odorless with ch4 chemical formula. arisanti et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 19-22 doi: 10.26554/ijems.2017.1.1.19-2220 other properties of methane gas (ch4), among others, can burn at 5-15%, have a boiling point of -161oc, and have a water solubility of about 35mg/ l at atmospheric pressure. the methane gas was first invented by alessandro volta from 1776-1778 who conducted research on manggiore lake and observed gas bubbles and found that the gas could burn [9]. methane gas can be stored in coal in 4 ways: 1) gas in micro pores and cleats, (2) water-soluble gases, (3) gas absorbed by molecular pull on micro pore coal particles and cleat surfaces, (4) gas absorbed in coal structure [10]. gas in coal is generally formed in two ways, biogenic gas and thermogenic gas [11]. for the biogenic gas, it occured in the 2 stages of the initial stage and the final stage. in the early stages, the gas formation was caused by the activity of early microfication of coalification, from peat-lignite to sub bituminous. the formation of gas in the final stage is also caused by the activity of the organism, but the process of occurrence after the coal seam is formed. coal is generally a quifer, where the activity of microorganisms in the aquifer can produce gas. this process can occur in any rank (rank) of coal. for the thermogenic gas, the gas produced in the coalification process due to increased pressure and temperature on the coal having a higher rank, was in sub bituminous a to high volatile bituminous upwards [12]. the gas content formed is closely related to the temperature and rank of coal as shown in figure 1 [13]. characteristics of coal methane gas is influenced by some parameters, such as sedimentary environment, coal distribution, coal rank, gas content, permeability, porosity, geological structure, and hydro geological conditions. coal as sedimentary rock is composed of elements of carbon, hydrogen, oxygen, nitrogen, and sulfur. the carbon content was contained in coal causes coal to become combustible. for coal, especially low calorie has a large porosity so that oxygen will be able to easily enter into coal, causing the oxidation reaction in coal. this oxidation reaction can cause heat happening to coal so that make emissions of gas co2, ch4, and h2s when coal is burned [6]. the formation of ch4 gas emissions occurs by the following reactions: 2 4c + 2h ch→ (1) another possibility is the formation of ch4 gas by the following methanezation reaction: 2 4 2co + 3h ch h o→ + (1) 2 2 4 2co + 4h ch 2h o→ + (1) the formation of ch4 gas emissions depends on the length time of combustion and combustion temperature methane gas (ch4) is formed in the initial process of coalification, where coal is still in peat condition, so methane gas (ch4) is mostly found in low rank coal. the low rank coal will have a low calorific value between from 4,830-6,360 kcal/kg (classification according to astm). thus the emission of methane gas (ch4) will be smaller if the rank and calorific value of coal will be higher, but it is also influenced by the combustion temperature. 2.3. materials and methods 2.3.1. material this type of research is a quantitative research. this research activity will be carried out in the materials processing laboratory of mining department of engineering faculty of sriwijaya university for coal combustion process and laboratory of pt. sucofindo palembang for examination of proximate and ultimate analysis. while the sampling location for coal quality analysis of methane gas emission (ch4) was done at pt. bukit asam (persero), tbk. kertapati palembang docks unit with calorific value level of 5,900 kcal/kg (ba-59), 6,300 kcal/kg (ba-63), 6,700 kcal/kg (ba-67) and 7,600 kcal/kg (ba-76). instruments used in this study include coal oven burner equipment complete with gas cylinders and regulator hose, calibrated multigas detector, anemometer, thermocouple, and stopwatch. 2.3.2. method stages performed in this study to achieve the purpose of this study include: table 1. air needs of combustion of different types of coal [8] proximate analysis variation of coal (% mass) anthracite bituminous sub bituminous lignite fixed carbon (fc) 83.3 70 45.9 30.8 volatile matter (vm) 5.7 20.5 30.5 28.2 moisture (m) 2.5 3.3 19.6 34.8 ash (a) 8 6.2 4 6.2 ultimate analysis carbon (c) 89.3 80.7 58.8 42.4 hydrogen (h) 2.9 4.5 3.8 2.8 sulfur (s) 0.7 1.8 0.3 0.7 oxygen (o) 0.7 2.4 12.2 12.4 nitrogen (n) 1.3 1.1 1.3 0.7 water (h2o) 2.5 3.3 19.6 34.8 hhv heat value (btu/lb) 13,710 14,310 10,130 7,210 air combustion requirements (lb air/lb coal) 10,423 12,819 9,098 6,423 figure 1. gas formation in relation to temperature [13] arisanti et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 19-22 doi: 10.26554/ijems.2017.1.1.19-2221 literature study gather all the information associated with the study. stage of preparation; set up the variable format measurement, equipment modification burning, and preparation equipment.sampling and data collection; coal samples from pt. bukit asam unit kertapati pier palembang with a calorie value of 5,900 kcal/kg (ba-59), 6,700 kcal/kg (ba-67), and 7,600 kcal/kg (ba-76). the collection data can be divided into two class, i.e. primary data: combustion temperature, combustion time, methane gas emissions generated, and air discharge in the combustion process. secondary data: coal quality data (proximate test, ultimate, and calorific value of coal), environmental condition of coal deposition, coal transport process from tanjung enim mining unit to kertapati pier unit, sample location map. coal and combustion testing measurements of natural gas emissions include ch4, co2, h2s, o2, (multigas detectors), measurement of combustion time (stopwatch), temperature measurement (thermocouple). processing and data analysis data processing using spss with quantitative was descriptive approach method and statistical method. data analysis by using descriptive associative, among others, analysis of the effect of quality and value of coal calorie to methane gas emission (ch4) in coal combustion process, temperature analysis to methane gas emission formation during burning process, conclusion 3. results and discussion 3.1. coal quality analysis many ways that can be done to know the quality of coal. in principle coal quality test can be known through two analyzes, namely proximate analysis and ultimate analysis. proximate analysis is an analysis whose purpose is to know: (1) moisture, consisting of free moisture, inherent moisture, and total moisture; (2) ash content; (3) volatile matter; (4) carbon blocked (fixed carbon). while the ultimate analysis is an analysis conducted on coal to know the elements of coal formers, among others, carbon, hydrogen, oxygen, nitrogen, and sulfur that exist in coal [7]. coal calorific value which is an indicator of coal quality is divided into two types, namely high heating value (hhv) and low heating value (lhv). high heating value (hhv) is obtained by burning coal as much as one kilogram and measuring the calories obtained using a calorimeter at 150 oc so that the moisture generated from this combustion condenses and releases its condensing calories. while low heating value (lhv) or low caloric value obtained by reducing the value of upper calories with water-condensing calories it contains [14]. coal quality classification aims to determine the variation of coal quality. there are two classifications that are used based on the proximate analysis and the calorific value of coal, namely tanjung enim mine brand (te) for unprocessed coal mining and market brand bukit asam (ba) for processed coal processing, such as blending. market brand classification (ba) is used for coal sales. calorific value of coal used in the study in accordance with the classification of the brand market (ba), among others, the caloric value of 5900 kcal/kg (ba-59), 6300 kcal/kg (ba-63) calories, 6700 kcal/kg (ba-67) calories, and 7600 kcal/kg (ba-76) calories. the classification of brand market coal (ba) for each calorific value used in this study can be seen in table 2. 3.2. methane gas emission (ch4) in coal methane gas emission (ch4) in this study can be seen from the measurement results, where for coal with a calorific value of 5900 kcal/kg (ba-59) the measurement is done until 72 minutes with average methane gas emission (ch4) of 3.98 ppm, and methane gas start out to emerge 7 minutes after the burning process of 0.3 ppm and continue to increase until time 72 minutes of 9.8 ppm. coal with a calorific value of 6300 kcal/kg (ba-63) has an average emission of 1.30 ppm with a measurement time of 53 minutes of 2.8 ppm and methane gas the first arises 10 minutes after the combustion process of 0.3 ppm. coal with a calorific value of 6700 kcal/kg (ba-67) has an average methane gas emission (ch4) of 0.26 ppm with a measurement time of 50 minutes, the gas emissions after of 50 minutes of 0.7 ppm and methane gas arising first after 19 minutes of burning with emissions of 0.2 ppm. while for coal with calorific value of 7600 kcal/kg (ba-76) the average methane emissions that occurred at 0.08 ppm with a burning time of 46 minutes, the largest methane gas emissions generated at the combustion process of 0.3 ppm and gas methane arises first after 34 minutes of burning process of 0.2 ppm. based on the above measurements can be seen the higher the calorific value of coal will be the smaller the gas emissions that occur and the longer time required for the combustion process that can cause the emission of methane gas (ch4), while the process of methane gas emissions will be smaller. 3.3. the effect of temperature on methane gas emission (ch4) combustion temperature will greatly affect the combustion process for each coal calorific value, where the higher the calorific value of coal, the temperature required for combustion process is also higher. in the coal combustion process the relationship between calorific value and combustion temperature with methane gas emission (ch4) that will arise can be seen from the research results the higher the quality of coal the required temperature for the combustion process will be greater and the methane gas (ch4) that occurs will be smaller . the results of this study indicate that coal with a calorific value of 5900 kcal/kg (ba-59) of methane gas (ch4) will arise at 31 °c with methane gas of 0.3 ppm, for coal with a caloric value of 6300 kcal/kg of methane gas emissions ch4) occurs at 40°c of 0.2 ppm, and coal with a calorific value of 6700 kcal/kg (ba-67) of methane gas (ch4) occurs first at 48°c of 0.2 ppm, whereas coal with caloric value 7600 kcal/kg (ba-76) new methane gas arises at 138oc temperature of 0.2 ppm (table 3). 4. conclusion table 2. classification of market brand coal (ba) based on proximate analysis result (exhibition unit and pjp) mine brand cv (kcal/kg,abd) tm (%,ar) im (%,adb) ash (%,adb) vm (%,adb) fc (%,adb) ts (%,adb) te 59 5900 28 13.1 6 40.4 40.5 0.6 te 63 6300 21 11.3 5 41.2 42.5 0.6 te 67 6700 18 7.8 5 41.5 45.7 0.6 te 76 7600 14 6.1 5 41.9 47 0.6 arisanti et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 19-22 doi: 10.26554/ijems.2017.1.1.19-2222 the result of methane gas (ch4) emission analysis to the calorific value of coal, the higher the coal calorific value, the methane emissions that will arise will be smaller. the average value of methane gas emissions (ch4) occurring in the coal combustion process for each calorific value, for an average calorific value of 5900 kcal/kg (ba-59) the average emission is 3.98 ppm occurs 7 minutes after the combustion process with the initial emission of 0.3 ppm, the average calorific value of 6300 kcal/kg (ba-63) the average emissions of 1.30 ppm arises 10 minutes after the burning of 0.3 ppm, the calorific value of 6700 kcal/kg (ba67) has average methane emissions. 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[13] geomagz, coal methane gas, non-conventional alternative energy, earth search geological resource center, geological agency, 2012. table 3. temperature and emission of methane gas (ch4) for each calorific calorific value (kcal/kg) t (0c) ch4 (ppm) 5900 (ba-59) 63.75 3.98 6300 (ba-63) 60.92 1.3 6700 (ba-67) 52.5 0.26 7600 (ba-76) 113.98 0.08 title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper potential application of consortium microbe from sea cucumber intestinal symbiont as preservatives for vaname shrimp marwa irfan hanif1, delianis pringgenies1*, gunawan widi santosa1, ervia yudiati1, ali djunaedi1, koesoemadj1, 1department of marine science, faculty of fisheries and marine science, diponegoro university, semarang, indonesia *corresponding author e-mail: pringgenies@yahoo.com abstract vaname shrimp is one of the most profitable export commodities in indonesia. however, the shrimp meat undergoes rapid quality degradation when shipped without any preservatives. this is an issue since the preservatives commonly found on the market are formalin-based. this study aims to discover a natural preservative solution by utilizing microbes. the objective of the study is to discover natural preservatives made of symbiont microbe in sea cucumber’s intestinal organ by antimicrobial activity screening. sea cucumber samples were collected from bandengan waters of jepara. there are 3 symbiotic microbe form intestinal cucumber that can inhibit the growth from bacillus cereus and pseudomonas aeruginosa. these three microbes are listeria sp., staphylococcus sp., and rothia sp. consequently, tested microbial samples were prepared into a consortium microbe and were tested further as a preservative agent for shrimp with a positive control parameter (cooling). the observations conducted in this study include organoleptic properties, acidity, total colony, proximate test (protein, water, ash, fat, and carbohydrate contents), and total volatile base-nitrogen (tvbn). the results found 3 active isolates are synergic one to each other as a bacterial consortium. acidity test of sample extract treatment measured a ph of 7.44, compared to the non-treatment result of 7.14. organoleptic test results of the shrimp indicated that the shrimp was acceptable for consumption. proximate test of the treatment did not show a significant difference compared to the positive control treatment. total colony and tvbn test on treated samples resulted in 48 x 105 cfu/ml and 39.62 mgn% respectively, whereas a similar test on non-treatment sample showed 119 x 105 cfu/ml and 45.31 mgn% respectively. it was concluded that the extract of sea cucumber symbiont microbe consortium showed potency in preventing meat quality degradation in shrimp, although treatment by freezing still produces a better result. keywords microbial symbiont, preservative, sea cucumber received: 14 agustus 2019, accepted: 27 september 2019 https://doi.org/10.26554/ijems.2019.3.3.106-111 1. introduction food decay is known as food degradation in normal storage (buckle et al., 2007). according tobarus et al. (2017), one factor in marine food decay was caused by bacteria with the growth of bacteria will cause physical and chemical changes of the food. ma’ruf (2012), stated that microorganism such as p. aeruginosa dan b. cereus had cause fish and other marine food. in this case, one of the important export commodity in indonesia with the risk of decay is a product of vanname shrimp (wijayanto et al., 2017). dealing with preservation in marine food in general such as frozen, smoking, radiation or food preservative additives. but this food preservation (radiation and frozen) will have a high operational cause. so that people will prefer to use low-cost synthetic preservative such as formalin (goon, 2014). the use of formalin will have a very bad effect on a human. formalin will cause irritation and inflammation in the mouth and esophagus, chest or stomach pain and in most savior condition is kidney failure. therefore the option use of natural food preservation will be needed (yulisa et al., 2014). the marine microbe is one of potential resource for bioactive component commercialization. microorganism with association with a marine organism such sea cucumber will be able to synthesize secondary metabolite in the host organism (pringgenies, 2010). according to ma’ruf et al. (2014), sea cucumber genus of holothuria had been proven as potential antibacterial ability from its bioactive component. antibacterial from sea cucumber had been effectively had proven as an antibacterial compound for b. cereus and p. aeruginosa. three symbiotic bacteria from intestine https://doi.org/10.26554/ijems.2019.3.3.106-111 hanif et. al. indonesian journal of environmental management and sustainability, 3 (2019) 106-111 of sea cucumber that are listeria sp., staphylococcus sp., and rothia sp. had antibacterial activity against these two contaminant microbes pringgenies et al. (2018). a consortium of bacteria is a community that had a more significant effect than a single isolate (asri and zulaika, 2016). symbiotic bacteria consortium from the intestine of sea cucumber has the antibacterial capability for b. cereus and which will inhibit microbial contaminant which can be used as a natural preservative. 2. experimental section 2.1 material the material used in the research was the three isolate of bacteria symbion, vanname shrimp (liptopenaeus vannamei) for experiment test, zobell 2216 e medium, and some other chemical reagent for proximate and tvbn test. equipment used for the research is oven, furnace, kjeldahl flask, soxhlet, incubator, conway disk, autoclave, and laminar airflow. 2.2 synergistic test among symbiotic bacteria listeria sp., staphylococcus sp., and rothia sp. from the intestine of sea cucumber tested for the synergistic test. one ose symbiotic bacteria isolate had been applied on top of each other in the zobell 2216 e medium. the sample was incubated for 24 hours and observed. if there is no inhibition zone, the isolate was synergistic one to each other in the consortium (asri and zulaika, 2016). 2.3 isolation of secondary metabolite isolate of symbiotic bacteria consortium was grown as a starter on 10 ml liquid zobell medium in 15 ml reaction tube and shook in 120 rpm speed for 3-5 days until its reach stationary phase. isolate the moved into 40 ml liquid zobell media the shook for 3-5 days with 120 rpm speed. culture of bacteria move into 50 ml centrifuge tube and centrifuge with 2800 g-force speed for 15 minutes to produce supernatant (rau et al., 2008). 2.4 preservation test of bacterial consortium supernatant in vanname shrimp the supernatant extract of the bacterial consortium was tested on vanname shrimp (l. vannamei ). preservation test divides into five control that is cooling (es), bacterial supernatant (3c), sterile seawater (as), sterile medium (ms), and without treatment (n). vanname shrimp shocked with all treatment for 10 hours (putra and mirdhayati, 2009). 2.4.1 tested parameters 1 ph (santoso, 2017). 2 total plate count (sitakar et al., 2016). 3 organoleptic (sni 01-2728.1-2006) 4 proximate: water (sni 01-2354.2-2006) ash (sni 23541-2010) fat (sni 01-2354.3-2006) protein (sni 01-2354.4-2006). karbohidrat atma (2018). 5 total volatile base-nitrogen (tvbn) (sni 01-2354.82009). 3. results and discussion 3.1 synergistic test among bacteria result of the symbiotic bacterial synergistic test showed no inhibition zone formed. meaning that the three symbiotic bacteria isolate were synergistic one to each other as a bacterial consortium. synergic bacteria to form a consortium will give optimum result than a single isolate of bacteria. the factor of bacteria isolates to form synergism to one another still unknown. some factor could effect of synergism are 1. synergism in the nutrition synthesis, 2. synergism among bacteria in undegraded material by other bacteria, 3. one type of bacteria has the ability to inhibit toxic compound to other bacteria (asri and zulaika, 2016). figure 1. synergistic test result 3.2 ph test on shrimp preservation value of some ph test in the shrimp preservation is on table 1. based on ph test in shrimp preservation range from 6,46 – 7,77 where according to purwa et al. (2012), ph ranged from 6,5 – 7,5 as a suitable ph for contaminant bacteria. ph value on treatment on shrimp with extract was 7,44 while on positive control is 7,42. table 1. ph test result no. treatment ph 1 es 7,42 ± 0,01 2 3c 7,44 ± 0,01 3 as 7,10 ± 0,01 4 ms 6,46 ± 0.00 5 n 7,14 ± 0,01 according to harsojo (2008), good ph value for food should be lower than 5,3 where the possibility of bacteria contaminant will be minimum. in reality value of ph in the shrimp product in the market range from 6,6 – 7,5. © 2019 the authors. page 107 of 111 hanif et. al. indonesian journal of environmental management and sustainability, 3 (2019) 106-111 meaning that is neutral and nonacid for human, but it is a good condition for bacteria contaminant. 3.3 total colony test of contaminant bacteria (tpc) result of total colony count in shrimp preservation as in table 2. table 2. total bacteria count no. treatment bacteria colony value (cfu/ml) 1 es 19 x 105 2 3c 48 x 105 3 as 114 x 105 4 ms 82 x 105 5 n 119 x 105 result of tpc in positive control (cooling) has value 19 x 105 cfu/ml, while in the supernatant value is 48 x 105 cfu/ml. this two value is are much lower than shrimp without any treatment that is 119 x 105 cfu/ml. result of tpc of all treatment is above the standard of 5 x 105 cfu/ml. but, according to purwa et al. (2012) based on directorate general of food and drug. value of tpc in food product should be about 50 x 105 cfu/ml and above this number is not suitable for consumption. based on result shrimp with treatment in es and 3c is still suitable for consumption. value of tpc is affected by the initial bacteria amount (sukmawati and hardianti, 2018). according to harsojo (2008), the value of bacterial contaminant in the shrimp product in the market is 10 – 58 x 105. value of negative control indicates that sterile media and sterile seawater will not effect on bacteria supernatant extract. 3.4 organoleptic test on shrimp preservation result of organoleptic test based on 10 respondent as in table 3. organoleptic tests were carried out by 10 respondents with a range of values 1-9. the evaluation points observed were shrimp appearance, shrimp smell, and shrimp texture. the highest organoleptic value was obtained by es shrimp and the lowest was by shrimp n (without treatment). based on sni 01-2728.1-2006 if the average organoleptic value is must be lower than 7, if the organoleptic value of the shrimp under that value, the shrimp is not suitable for consumption. untreated shrimp (n) has a value of 5.70. so, based on the quality standards the shrimp is not suitable for consumption. while the organoleptic value of shrimp with other treatments is more than 7. 3.5 water and protein content test the results of the water and protein content in the shrimp product shows as in table 4. the highest value of water content is found in n shrimp with a value of 78.73% where this value is directly proportional to bacterial colonies number in table 3. organoleptic test result no. treatment organoleptic value 1 es 8,53 2 3c 7,77 3 as 7,37 4 ms 7,43 5 n 5,70 shrimp n which is as much as 119 x 105 cfu / ml. the excess water content in the material will cause the material to be easily overgrown by contaminant bacteria. this is similar to bawinto et al. (2015) the content of excess water content in a material can cause food to become rapidly damaged because it is used as a microorganisms growth’s medium. shrimp with extracts or 3c shrimp have an average water content value so that bacterial growth in shrimp 3c is minimum. however, the water content in the es positive control was noted to be high, this was probably due to the ice melting and seeping into the shrimp meat. the lowest value of water content is found in as shrimp where it is estimated that immersion in sterile seawater will cause the liquid in the shrimp to come out to a higher concentration. the value of protein content will also affect the number of contaminant bacteria that grow and cause the decay path faster. the highest value of protein content is found in as shrimp. high levels of protein result in reduced water content in shrimp, this may also be a factor why the as water content is the lowest. according to yuarni et al. (2015), the high protein content will result in increased bacterial growth because protein is an important nutrient for bacteria. so this factor is what causes the total value of colonies in as shrimp to be very high. the value of protein content in 3c shrimp is not much different from the value in the positive control es shrimp where the value of both includes the average value. overall the value of shrimp protein levels still meets the quality standard of more than 15%. table 4. add caption no. treatment water (%) protein (%) 1 es 78,15 18,69 2 3c 77,77 18,45 3 as 76,57 19,41 4 ms 78,27 17,26 5 n 78,73 17,78 3.6 fat and ash content test the value of fat content and an ash content of shrimp in each treatment as in table 5. fat content in shrimp samples from three samples of es, 3c, and as shrimp still showed values that were suitable with existing quality standards. © 2019 the authors. page 108 of 111 hanif et. al. indonesian journal of environmental management and sustainability, 3 (2019) 106-111 according to fendjalang (2018), the fat content in fishery products ranges from 1.00 1.40%. the value of fat content in ms and n shrimp is less than 1.00%, this is probably due to the high water content in these two shrimp. khasrad and arfal (2016) mention that the low level of fat in food caused by high water content. contaminant bacteria will also play a role in changing the conditions of fat in a substance. the value of ash content obtained in this study shows that the ash content in ms shrimp samples exceeds the existing quality standard. the value of ash content in fishery products must be lower than 2%. according to erni et al. (2018), high ash content can also cause by the high temperature and duration of drying in a test material. table 5. fat and ash content test result no. treatment fat (%) ash (%) 1 es 1,05 0,91 2 3c 1,15 1,49 3 as 1,10 1,67 4 ms 0,86 2,44 5 n 0,94 1,16 table 6. carbohydrate content calculation result no. treatment carbohydrate (%) 1 es 1,20 2 3c 1,17 3 as 1,25 4 ms 1,17 5 n 1,39 3.7 carbohydrate content calculation carbohydrate content was calculated using the by difference method as in table 6. calculation by difference is a gross calculation that subtracts 100% with the value of other chemical content so that crude fiber will be included in the counting (suptijah, 2012). the highest carbohydrate value is in the n sample then as, while the es, 3c, and ms samples are lower than that number. high carbohydrate values can be an indicator of the high growth of contaminant bacteria. according to andarti and wardani (2015), carbohydrates are a source of energy for the body and a simple form of carbohydrates can be used as an energy source for contaminant bacteria growth. 3.8 tvbn (total volatile base-nitrogen) test result of tvbn in each treatment shows as in table 7. the results of tvbn values in shrimp are directly proportional to the total value of colonies of contaminant bacteria in shrimp as in figure 2. tvbn or total volatile base-nitrogen is a measurement of volatile material in a substance (tapotubun figure 2. comparison between tvbn and total colony table 7. tvbn test result no. treatment nilai tvb-n (mgn%) 1 es 36,30 2 3c 39,32 3 as 44,49 4 ms 43,95 5 n 45,31 and laouhenapessy, 2008). as the graph in figure 2, the more total contaminant bacterial colonies will increase the value of tvbn in the sample. this was since contaminant bacteria will accelerate the formation of enzymes that function as protein degradation. farahita et al. (2012) opine that the process of tvb occurs due to the work of proteolytic enzymes that break protein bonds and the result in this degradation will produce a number of volatile bases such as ammonia, h2s, and foul-smelling trimethylamine. enzymes roles in degradation down proteins are produced by bacterial activity. 4. conclusions three isolates of symbiotic bacteria from sea cucumber lister sp., staphylococcus sp., and rothia sp. have synergic one to another. supernatant extract of the three bacterial consortia has a significant potential for shrimp product preservation compared to nontreatment. result of positive control using cooling treatment still give a better result. references andarti, i. y. and a. k. wardani (2015). pengaruh lama fermentasi terhadap karakteristik kimia, mikrobiologi, dan organoleptik miso kedelai hitam (glycine max (l)). jurnal pangan dan agroindustri, 3(3); 889–898 asri, a. c. and e. zulaika (2016). sinergisme antar isolat azobacter yang dikonsorsiumkan. jurnal sains dan seni, 5(2); 57–59 © 2019 the authors. page 109 of 111 hanif et. al. indonesian journal of environmental management and sustainability, 3 (2019) 106-111 atma, y. 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(2015). laju perubahan kadar air, kadar protein dan uji organoleptik ikan lele asin menggunakan alat pengering kabinet (cabinet dryer) dengan suhu terkontrol. jurnal pendidikan teknologi pertanian, 1; 12–21 © 2019 the authors. page 110 of 111 hanif et. al. indonesian journal of environmental management and sustainability, 3 (2019) 106-111 yulisa, n., e. asni, and m. azrin (2014). uji formalin pada ikan asin gurami di pasar tradisional pekanbaru. jurnal online mahasiswa fakultas kedokteran, 1(2); 1–12 © 2019 the authors. page 111 of 111 introduction experimental section material synergistic test among symbiotic bacteria isolation of secondary metabolite preservation test of bacterial consortium supernatant in vanname shrimp tested parameters results and discussion synergistic test among bacteria ph test on shrimp preservation total colony test of contaminant bacteria (tpc) organoleptic test on shrimp preservation water and protein content test fat and ash content test carbohydrate content calculation tvbn (total volatile base-nitrogen) test conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper species composition and length-weight relationship of anguillid eels habited in bengkulu waters, indonesia ni komang suryati1,2, fauziyah3*, ngudiantoro4, 1 graduate school of resources management, universitas sriwijaya, indonesia 2 research institute for inland fisheries and fisheries extension 3 marine science program study, universitas sriwijaya, indonesia 4 mathematic study program, universitas sriwijaya, indonesia *corresponding author e-mail: siti_fauziyah@yahoo.com abstract management of euryhaline species, such as anguillid eel, is very important. anguillid eel is an important economic fish which the partly of its life cycle spent in inland waters then migrates into the ocean for spawning. the objective of this study is to identify the morphological diversity and length-weight relationship of anguillid eels in this province. the total of 148 individuals of elver and adult anguillid eels were caught was identified using the comparison of ano-dorsal with total length parameter. cluster analysis was obtained based on measurement of morphometric parameter. the current work used cluster analysis and dendrogram to group the population characteristic of anguilla eel. it revealed that in the jenggalu, kungkai and manna rivers of bengkulu province, there are two groups of anguilla eel with significant difference of ano-dorsal length. the value of the ano-dorsal varied from 2.56 ± 1.54 and 17.78 ± 1.33 for a.bicolor bicolor and a.marmorata, respectively. the length-weight relationships between total length (tl) and weight (w) for anguilla bicolor and a.marmorata were found to be highly significant (r2 > 0.94, p < 0.001). the average value of ’b’ for length and weight were higher than 3, i.e., 3.2677 and 3.4821 in a.bicolor and a.marmorata respectively which indicated a positive allometric growth trend of this species in the studied area. keywords anodorsal length, lwr, anguillid eel, bengkulu received: 23 february 2018, accepted: 15 april 2018 https://doi.org/10.26554/ijems.2018.2.2.48-53 1. introduction management of euryhaline species, such as anguillid eel, is very important. anguillid eel is an important economic �sh which the partly of its life cycle spent in inland waters then migrates into the ocean for spawning. commercial eel �shery activity is distributed all over the world (de leo and gatto, 2001). based on data from food and agriculture organization, united nations (fao), eel’s production signi�cantly increases from 17,775 t in 1950 (only 3% from aquaculture) to 280,000 t in 2007 (96% from aquaculture) and its production stabilized since 2008 to 2010. there are 19 species/subspesies of anguillid eel distribute all over the world covering indopaci�c, atlantic and oceania. indonesia has 10 species such as anguilla bicolor bicolor (indonesian short �n eel), anguilla bicolor pasi�ca, anguilla marmorata, anguilla nebulosa nebulosa, anguilla borneensis, anguilla celebescencis anguilla megastoma, and anguilla interioris (fahmi, 2015; sugeha and suharti, 2008). the geographical position of rivers in the bengkulu province which face directly to indian ocean is the potential habitat for anguillid eels. kungkai, jenggalu and manna river are located in the bengkulu. there are �owing into indian ocean directly. research on the existence and distribution of anguillid eel in indonesia has been conducted widely, generally in the java island. whereas in the other areas such as bengkulu is limited. the existence of anguillid eel in bengkulu province results in the high demand of eel seeds from eel farm in the java island. therefore, it is necessary to manage the anguillid eel resources for its sustainability. certainty taxonomy is required for managing the anguillid eels resources. therefore, morphological identi�cation is needed for anguillid eels species in bengkulu. furthermore, the knowledge on quantitative aspects such as length-weight relationship, condition factor, growth, and recruitment are important tools for the adequate management of for this species (king, 2007; ndome et al., 2012). the length-weight relationships also help to �gure out the condition, reproduction history, life history, and the general health of �shing species https://doi.org/10.26554/ijems.2018.2.2.48-53 suryati et. al. indonesian journal of environmental management and sustainability, 2 (2018) 48-53 figure 1. the sampling site of anguillid eels in bengkulu province, indonesia (nikolsky, 1963; wootton, 1990, 1992; pauly, 1993) and is also useful in local and interregional morphological and life historical comparisons in species and populations. therefore, the length-length relations of species under various environmental conditions should be known. the objective of this study is to identify the morphological diversity and length-weight relationship of anguillid eels in this province. 2. experimental section 2.1 description of research location the research location of anguillid eel �sh was conducted in three locations which is the eel’s �shing ground. there were kungkai, jenggalu and manna river in bengkulu province (fig. 1). anguillid eel’s sampling was done by using bamboo traps and pole and line (warm bait) in june and july 2016. laboratory analysis was conducted at the �sh biology laboratory, research institute for inland fisheries. 2.2 sample analysis anguillid eel’s samples were collected from the �shermen in each river. there was only yellow eel’s stage which was caught and no glass eel found in the research. glass eel is a seed that has no pigmentation development in the body. the glass eel will become yellow eel when entering the river and rapidly develop pigmentation which stay in freshwater for growth for many years before they become mature as “silver eel” and migrate back to the ocean for spawning. all of samples were preserved by using 90% alcohol for subsequent analysis in the laboratory of research institute for inland fisheries. morphological identi�cation for freshwater eel is one of the technical requirements for identi�cation. species determination used the key identi�cation based on literature i.e (arai and takaomi, 2016; tesch et al., 2003; silfvergrip, 2009). a sharpjawed vernier caliper graded to 0.1 mm used for measuring the morphological character such as total length (tl), head figure 2. morphological character of anguillid eels (tl: total length; hl : head length; pd : predorsal length; pa: preanal length (tesch, 2003)) figure 3. characteristics of anodorsal distance measurements on anguilla eel (hakim, 2015) length (hl), predorsal head length (pdhl), pre anal head length (pahl), pre dorsal length (pdl), pre anal length (pal) and anodorsal length (ad) (fig. 2). equation to distinguish the species for adult eel is anodorsal length (ad) (reveillac et al., 2009; rovara and amarullah., 2007). the characteristic expressed by ege’s in 1939 have been widely accepted now. this study used species identi�cation by using the ano-dorsal parameter which cheaper and faster. according to that equation, anguillid eel classi�ed into two group as follows, long �n and short �n. long �n is the anguillid eel which has the long ano-dorsal length, while short �n is the opposite. based on di�erences in anodorsal length, body coloration, number of vertebrae combined with genetic cluster, there are 16 species of anguillid eel in the world (arai and takaomi, 2016). in addition to the color pattern, other species distinguishing characteristics in all anguillid eel stadia are performed by measuring ano dorsal parameter which is divided by total lengths as the following equations (reveillac et al., 2009; rovara and amarullah., 2007): a−d%= (ld−la) lt ·100 (1) where lt is the total length, ld is the length of dorsal �n and la is the length of anal �n. short�n has ano dorsal value 0-5 while long�n 7-17 (rovara and amarullah., 2007). more speci�c [14] ad/tl for anguilla bicolor bicolor is ranged from 0-3, a. nebulosa 7-13 and a. marmorata 14-17. the length-weight relationships for weight were calculated using the equation, w = alb (ricker, 1979), where ‘a’ is a coe�cient related to body form and ‘b’ is an exponent indicating iso© 2018 the authors. page 49 of 53 suryati et. al. indonesian journal of environmental management and sustainability, 2 (2018) 48-53 figure 4. frequency distribution of ano-dorsal to total length (ad/tl) % anguilla bicolor bicolor and anguilla marmorata in bengkulu province metric growth when equal to 3. the statistical signi�cance level of r2 was estimated by linear regressions on the transformed equation, logbw = log a + b * logtl. the length-weight relationship between males and females were not calculated separately. all statistical analyses were evaluated at p < 0.05 signi�cance level. 2.3 cluster analysis morphometric measurement on anguillid eel is used to decide its population character. cluster analysis was obtained based on each parameter value on morphometric measurement. this analysis was performed using statistica software. figure 5. cluster analysis based on morphometric characterize between a.bicolor bicolor and a.marmorata in bengkulu province 3. results and discussion the total number of samples for this study is 148 individuals of anguillid eel in three locations. then, the samples identi�ed based on morphological characters such as body coloration and ano-dorsal parameter that determines whether the samples are long �n or short �n. the result of initial identi�cation indicated that there are two species of anguillid eel in bengkulu which have di�erent characteristic. table 1 showed the morphological identi�cation of anguillid eel sample in bengkulu province. the �rst species, a. bicolor bicolor, showed characteristics of the body coloration is plain (without pattern/un marbled) and has short �n which was found in the kungkai and jenggalu rivers (northern part of bengkulu province. a. marmorata, second species, was characterized by marbled body color and has a long �n and was found in the manna river (southern part of bengkulu). the result of initial identi�cation based on morphological identi�cation is the initial process to facilitate the next steps for identi�cation the species. table 2 showed that a. bicolor bicolor in kungkai and jenggalu river has the same characteristics of morphometric such as head length (hl) 0.2 to 9.1 (in average: 4.25±1.01) cm, pre dorsal length (pdl) 5.8 to 27.5 (in average: 12.99±2.98) cm, pre anal length (pal) 7.9 to 29 (in average: 13.89±3.08) cm and ano dorsal length (ad) 0.3 to 4.9 (in average: 2.56±1.54) cm. while a. marmorata in manna river showed the characterize as follows head lenght (hl) 5.1 to 6.1 (in average: 5.58±0.27) cm, pre dorsal length (pdl) 7.5 to 14.6 (in average: 10.90±1.96) cm, pre anal length (pal) 12.6 to 294.7 (in average: 18.03±3.07) cm and ano dorsal length (ad) 15.5 to 20.8 (in average: 17.78±1.33) cm. comparison of ano dorsal length (ad) to total lenght (tl) used to di�erentiate the anguillid eel species (reveillac et al., 2009; rovara and amarullah., 2007). matsui (rovara and amarullah., 2007) has devided the anguillid eel into two groups based on the length of the �n as follows, short�n which 0 to 5 and long�n 7-17. more detailed on (reveillac et al., 2009) showed that ad/tl for species a. bicolor bicolor is 0 to 3, a. nebulosa 7-13 and a. marmorata 14-17. the result showed that there were two ano-dorsal length groups in this study. first group was a.bicolor bicolor which has 0.3 to 4.9 of anodorsal lenght. other groups was showed the result 15.5 to 20.8 as a.marmorata. figure 2 described the distribution frequency for that species in this study. the total © 2018 the authors. page 50 of 53 suryati et. al. indonesian journal of environmental management and sustainability, 2 (2018) 48-53 table 1. morphological identi�cation of anguillid eel in bengkulu province location local name common name scienti�c name characteristic kungkai river sidat indonesian short�n eel a.bicolor bicolor body color is no pattern/un-marbled and has short �n jenggalu river sidat indonesian short�n eel a.bicolor bicolor body color is no pattern/un-marbled and has short �n manna river pelus giant mottled eel a.marmorata body color is marbled and has long �n table 2. characteristics of two species of anguilla eels in bengkulu species site n (ind) character hl (cm) pdl (cm) pal (cm) ad/tl(%) a. bicolor bicolor kungkai 91 range 0.2 – 6.8 7.2 – 19.3 7.9 22 0.3 – 4.5 average± sd 4.17 ± 0.87 12.92 ± 2.40 13.68 ± 2.6 2.99 ± 0.93 jenggalu 34 range 3 – 9.1 5.8 – 27.5 oct-29 1.4 – 4.9 average± sd 4.84 ± 1.89 14.25 ± 5.82 15.40 ± 5.33 3.08 ± 1.02 total 125 range 0.2 – 9.1 5.8 – 27.5 7.9 – 29 0.3 – 4.9 average± sd 4.25± 1.01 12.99 ± 2.98 13.89 ± 3.08 2.56 ± 1.54 a. marmorata manna 23 range 5.1 – 6.1 7.5 – 14.6 12.6 – 24.7 15.5 – 20.8 average± sd 5.58 ± 0.27 10.90 ± 1.96 18.03 ± 3.07 17.78 ± 1.33 125 individual of anguillid eel was a.bicolor bicolor with percentage of ano-dorsal length 2.56 % and 23 individual sample of a.marmorata with the ano-dorsal length 17.78 %. percentage of ano-dorsal length 2 was dominant with the frequency 44 individual. while for a.marmorata species is dominated by 16 of ano-dorsal length with the total number of individual 6 (figure 4). there are 3 species of anguilla eel in bengkulu (fahmi, 2015) such as a. bicolor bicolor, a.marmorata dan a. nebulosa nebulosa by using the analysis of the glass eel/juvenile stage. meanwhile, there are only two species of anguilla eel which are identi�ed by elver and yellow eel stage which morphological identi�ed based on ano-dorsal length (ad/tl) as a.bicolor bicolor and a.marmorata. ad/tl is the useful for distinguish the species of anguilla eel in the rivers that leads to palabuhan ratu bay (sugeha et al., 2001). it was supported by this study that this method can also be applied to distinguish the anguillid species in bengkulu province. overlap of the ad/tl percentage did not occur on this study because between a. bicolor bicolor and a. marmorata has signi�cant di�erence on this characteristic. the examples of the overlapping on this character occur between two sub species a.bicolor bicolor and a.bicolor pasi�ca (sugeha and suharti, 2008). therefore, watanabe (watanabe and tsukamoto., 2004) suggested that identi�cation based on ege must be supported by the existence of geographic data information. geographical information of the source of the anguillid eels makes it easier to identify the species of the anguillid eels. for instance, a.bicolor bicolor distributed on indian ocean coast from south africa, the arabian peninsula, srilanka to the west of indonesia and the western part of australia (robinet et al., 2003). this species is thought to be spawning in the eastern indian ocean precisely on the west cost of sumatera island. cluster analysis by using the dendrogram showed that there were 2 groups of anguilla eel based on grouping of characterized population. these characteristics described by the line which divided the sample into two groups of population. cluster analysis showed (fig.5) that a.bicolor bicolor has signi�cant di�erence on percentage of anodorsal (ad/tl) with a.marmorata. this result was supported by the dendrogram that there was one group of a.bicolor bicolor in jenggalu and kungkai river. this indicated that sample from the adjacent rivers will have the same morphological characters. meanwhile, the sample from manna river which is located far apart from another station show di�erent species of anguilla, a.marmorata. the di�erences are also related to the habitat characteristics of the three rivers. length-weight relationships for anguillid eesl and the total sample population were determined and shown in table 3 and figure 6. analysis of covariance revealed signi�cant di�erences between sexes for the slopes (b) of the regression lines (p < 0.05). © 2018 the authors. page 51 of 53 suryati et. al. indonesian journal of environmental management and sustainability, 2 (2018) 48-53 figure 6. length-weight relationship a.bicolor bicolor and a.marmorata in bengkulu province table 3. add caption species n total length (cm) total weight (g) relationship parameter range mean±sd range mean±sd a b r a.bicolor bicolor 125 16.5-63.5 32.1±6.6 6.0-420.9 50.3±47.7 0.0005 3.2677 0.9453 a.marmorata 23 28.1-56.8 40.0±7.6 38-477 161.2±118.2 0.0004 3.4821 0.9623 according to le cren (1951) since fat and water content of �sh may vary according to temperature therefore the lengthweight relationships in �shes are related to the seasonal variation. sinha (1973) stated that the change in ’b’ value shows allometric growth of the body due to the in�uence of numerous factors such as seasonal �uctuations, changes in physiological condition during spawning periods, gonad development, sex, physicochemical conditions of the environment and nutrition conditions of the environment. sekharan (1998) have also observed an inter speci�c for ’b’ that remains constant at ’3.0’ for an ideal �sh. the result showed that values for ’b’ for length and weight were higher than 3, i.e., 3.2677 and 3.4821 in a.bicolor bicolor and a.marmorata respectively, which were of expected range and indicated that the growth is almost positive allometric on anguillid eels. however, wootton (1992) opined that b < 3 indicates that the �sh gets relatively thinner as they grow larger while b > 3, it is plumper as it grows larger. the values of coe�cient of determination (r2) calculated for lwr relationships tl-wt a.bicolor bicolor and a. marmorata (tables 3) were 0.9453 and 0.9623, respectively which are highly signi�cant (p < 0.001). regression coe�cients obtained from length-weight relationships (l-w) which are indicatives of isometric or allometric growths di�er not only between species but sometimes also between stocks of same species. the development of �sh involves several stages, each of which has its own length-weight relationships. there may also be di�erences in the relationships due to sex, maturity, season, and environmental conditions (e.g. pollution). 4. conclusions the current work successfully used cluster analysis and dendrogram to group the population characteristic of anguilla eel. it revealed that in the jenggalu, kungkai and manna rivers of bengkulu province, there are two groups of anguilla eel with signi�cant di�erence of ano-dorsal length. the value of the ano-dorsal varied from 2.56 ± 1.54 and 17.78 ± 1.33 for a.bicolor bicolor and a.marmorata, respectively. furthermore, the present study provides an important contribution to baseline data on the length-weight relationships of the a.bicolor and a.marmorata which are important tools for the adequate management of the �sh stocks and populations. the provided data on the lwr would be bene�cial for �shery biologist’s managers to impose suitable regulations for sustainable �shery management and conservation programs in the region. acknowledgement gratitude is delivered to the research institute for inland fisheries and extension fisheries, which has funded this activity (budget year 2016). we thank the sta� members of riifef: dr.dina muthmainnah, yanu prasetyo, and raider sigit for their participation and assistance during the �eld trips. special thanks to prof. ngurah.n. wiadnyana for assisting during the preparation of this paper. references arai and takaomi (2016). biology and ecology of anguillid eels. crc press taylor and francais © 2018 the authors. page 52 of 53 suryati et. al. indonesian journal of environmental management and sustainability, 2 (2018) 48-53 de leo, g. and m. gatto (2001). a stochastic bio economic analysis of silver eel �sheries. ecological applications, 11; 281–294 fahmi, m. 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(1990). ecology of teleost �shes. chapman and hall, london, 404 © 2018 the authors. page 53 of 53 introduction experimental section description of research location sample analysis cluster analysis results and discussion conclusions indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article doi: 10.26554/ijems.2017.1.1.23-2623 received: 15 september 2017 accepted: 29 november 2017 *corresponding author email: hisnirahmi@gmail.com study of chemical characteristics of the lambidaro river for sustainable environment hisni rahmi1.*, restu juniah1, azhar kholiq affandi2 1 mining engineering department, faculty of engineering, sriwijaya university, palembang 30319 2 physics, faculty of mathematics and natural science, sriwijaya university, palembang 30319 abstract residents, who live along the lambidaro watershed, generally use river water to meet their daily needs such as bathing, washing and latrines. around of lambidaro is a residential and industrial group such as rubber industry, workshop, home industry, and mining. the activities contained along the watershed can lead to an increase in river water pollution load which can be seen from chemical characteristics. increased pollution loads can cause the river environment to be unsustainable for the community. sustainable environment means that the environment as a provider of resources for human life is able to maintain its carrying capacity. the purpose of study is to determine the chemical characteristics of river due to sand mining activities for the environment sustainable. this research is using pollution index method with parameter of chemical characteristics measured that is ph, do, cod, bod5, fe, mn, nh4, nitrate, and nitrite. the results of analysis of water chemical characteristics of the river indicate that the part close to estuary of the river is in good condition indicating that the location is environmentally sustainable. meanwhile, the upstream to the middle river body is in mild contamination condition which means that the river environment has been contaminated. keywords: chemical characteristics, water river, pollution index 1. introduction river is defined as fresh water flowing from its source on land to and emptying in the larger seas, lakes or rivers [1]. another definition of river is a natural or artificial water channel or container in the form of water drainage network along with the water, starting from upstream to estuary, with right and left boundary by line border [2]. rivers are used as a source of water, for obtaining food, for transportation and defense purposes, as a source of hydropower for driving machinery, for bathing, and as a means of waste-disposal [3]. palembang city is a riverbank city. one of the rivers in palembang is lambidaro river. the lambidaro river is one of the musi river basin systems. along the lambidaro watershed is a residential area, industrial groups such as rubber industry, workshop, home industry, and mining. the activities contained in the lambidaro watershed impact on the degradation of river water quality. waste into the river body such as household waste, mining waste, rubber industry waste, workshop and many other. meanwhile, lambidaro river water is used by the community to meet daily needs such as bathing, washing, and latrines. this will certainly have an impact on the people who use the water. mining activities is one of the activities that can be a source of pollutants for the lambidaro river. sand mining is a practice used to extract sand, such as on a river bed [4]. mining activities can have an impact on the environment, especially the watershed environment. environmental problems occur when the rate of extraction of sand, gravel and other materials exceeds the deposition rate. soerjani et al argues that the taking and utilization of resources with technology or industrialization can degrade the quality of the environment [5]. these problems include the destruction of river ecosystems, degradation of quality of river water, increasing water pollution load, sedimentation, and others. based on the opinion of soejarni et al, the sand mining activities of mining companies have the potential impact on the quality of the lambidaro river. environmental problems caused by the exist various activities along the lambidaro watershed can make this environment no longer sustainable. sustainable environment here means environment that can maintain the carrying capacity of the environment as a provider of resources for human life. the one of river environment indicator be sustainable, if the quality of the river water is in a condition below the established water quality standard. the quality standard shall be a measure of the extent of living organisms, substances, energies, or components present or must exist and / or polluted elements present in water [6]. the quality of water quality can be seen from the biological, chemical and physical parameters. this paper will discuss the chemical nature of the lambidaro river water for a sustainable environment. water chemical characteristic measured include ph, do, cod, bod5, iron (fe), manganese (mn), free ammonia (nh4), nitrate, and nitrite. 2. experimental section this research was conducted at lambidaro river of palembang city, south sumatera. sampling of river water is carried out at 5 points along the lambidaro watershed as seen in figure 1. the next step after water samples that have been taken is conducted laboratory tests on water chemical characteristics. chemichal characteristics of lambidaro river water conducted by laboratory tests are ph, do, cod, bod5, iron (fe), manganese rahmi et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 23-26 doi: 10.26554/ijems.2017.1.1.23-2624 (mn), free ammonia (nh4), nitrate, and nitrite. the next step is to conduct water quality analysis of this river using pollution index method [8]. 2 2 2 i i ij ijm r j c c l l pl     +          = (1) where: pij = pollution index for designation (j) lij = concentration of water quality parameters ci = concentration of water quality parameters (ci/lij)r = value (ci/lij) on average (ci/lij)m = value (ci/lij) on maximum the pollution index method can directly relate the level of contamination to whether or not a river is used for a particular use and with the value of certain parameters. determination of status of river water quality can be seen based on pollution index criteria as follows: 0 ≤ pij ≤ 1.0 comply quality standard (good condition) 1.0 < pij ≤ 5.0 mild contamination 5.0 < pij ≤ 10 medium contamination pij > 10 heavy contamination 3. results and discussion lambidaro river is located in palembang city. lambidaro river has an area of 50.52 km2 and width ± 8 m [9]. the lambidaro river is one of the musi river flow systems. activities that exist around these rivers such as the activities of home industries, workshops, mining, agriculture, human settlements, and other activities. the mining activities located around the lambidaro river are sand mining. this sand mining activity is precisely located near musi ii or ± 1 km from the estuary of the river lambidaro [10]. sand mining activities are done by dredging and also suction pumps. if mining activities are open in the water catchment area, it can cause disruption of the water system in a region that may be much wider than the mining area itself [11]. the environment to be affected by mining activities is the river system. sand mining is expected to have an impact on the lambidaro river environment. this sand mining activity is expected to contribute to the entry of waste into water bodies that can lead to degradation of river water quality. the decrease of water quality due to sand mining can be caused by the increase of river basin materials resulting from sand mining activities. the basic material of the river that is lifted to the surface of the river is merged with river water. this indicates the burden of pollution that enters the water body and may cause a decrease in river water quality. the decrease of river water quality can be seen from 3 parameters of water properties, namely biological, chemical and physical. the chemical of the water tested can be an indicator of whether the quality of the water under study is in good or polluted conditions. comparison between laboratory test results with established water quality standards can indicate in which parameters a high pollution load. thus it can be estimated the cause of the water bodies. the water quality reduction will certainly affect the sustainability of the environment of region. it mean, the environment is no longer able to provide water with good quality in accordance with predetermined standards or quality standards for the community environment. the study of chemical characteristics of the lambidaro river done by taking samples of water at 5 points of measurement. the parameters of chemical characteristics tested were ph, do, cod, bod5, iron (fe), manganese (mn), free ammonia (nh4), nitrate, and nitrite. the following shows the water quality of the lambidaro river compared to the class i water quality standard figure 1. research location lambidaro river [7] table 1. chemical characteristics quality of lambidaro river water [7] no. characteristics unit quality standard* l1 l2 l3 l4 l5 1 ph 6 – 9 6.87 6.81 6.24 6.38 6.08 2 do mg/l 6 3.12 3.26 3.6 3.83 3.12 3 bod5 mg/l 2 1.85 1.8 2.51 2.56 3.04 4 cod mg/l 10 7 7 8 9 12 5 nh3-n mg/l 0.5 0.06 0.08 0.08 0.14 0.09 6 nitrat mg/l 10 0.15 0.18 0.12 0.08 0.11 7 nitrit mg/l 0.06 0.036 0.034 0.039 0.023 0.032 8 besi mg/l 0.3 0.08 0.09 0.19 0.09 0.11 9 mangan mg/l 0.1 0.03 0.03 0.04 0.05 0.03 * standard quality based on governor regulation south sumatera number 16 in 2005 description: l1: estuary of the lambidaro l2: karang sari l3: canal irrigation l4: canal bukit baru l5: polygon retention pond rahmi et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 23-26 doi: 10.26554/ijems.2017.1.1.23-2625 in table 1. based on table 1, it can be seen that the ph value of each sampling site point is below the required ph value standard. ph indicates the concentration of hydrogen ions in water [12]. normal water ph values are approximately neutral, ie between ph 6 and 9, while the polluted water ph, such as wastewater, varies depending on the type of effluent. this indicates that the ph of the lambidaro river is in normal condition. the point of measurement of l1 and l2 has a high ph value compared to other locations. this is thought to be due to the introduction of alkaline minerals into the water bodies at the site. alkaline minerals may enter the water bodies of l1 locations as they are within the proximity of sandstone mining activities. according to nybakken [13], do or dissolved oxygen in water comes from air diffusion and photosynthesis results of chlorophyllic organisms that live in a waters and are required by the organism to oxidize the nutrients that enter the body. based on table 1, the do score at each point of measurement is below the standard set value. meanwhile, the bod5 value for the point of measurement of l3, l4, and l5 is above the predefined quality standard. bod is a test to measure the amount of biodegradable organic matter (materials that can be destroyed or decomposed by living organisms) present in water samples [14]. the high bod5 value at the point of measurement of l3 (canal irrigation) is estimated to be caused by a pile of garbage around the river. meanwhile, the high bod5 value at the point of measurement of l4 (canal bukit baru) is estimated to be caused by the inclusion of agricultural pesticide residues by the runoff of rainwater and also the covering of the water surface by various plants such as water hyacinth. the measurement point l5 (polygon retention pond) also shows a high bod5 value. this is because the entry of organic and inorganic waste into water bodies. incoming garbage is household waste, such as plastic, food scraps, and also detergent. the causes of high bod5 values at these three sites are supported by the opinion that the cause of increasing the bod5 value is due to the high factor of domestic waste, in the form of organic and inorganic garbage and detergent, besides organic pollutants can also derive from pesitida residues originating from agriculture carried to the river by runoff rainwate [15]. cod is the amount of oxygen needed to oxidize chemically organic materials. high cod values will result in reduced dissolved oxygen content in river water [16]. the maximum quality standard required cod value is 10 mg/l. based on table 1 it can be seen that the cod value at the point of measurement l5 (polygon retention pond) is above the required standard of 12 mg/l. this is allegedly due to the entry of domestic waste into water bodies. the high cod value at this location is in line with the high bod5 value of this location as well. this is because bod and cod are closely related, where bod is the amount of oxygen required for the degradation of biological incoming water bodies, while cod is the amount of oxygen needed to degrade chemically incoming materials. the value of cod and bod indicate the existence of interconnection, where the higher the bod value, the higher the cod value of the waters. the value of nh4 (ammonia) along the lambidaro watershed is in good condition. that is, the value of nh4 at each location is below the predefined quality standard. however, according to effendi [17], ammonia levels in natural waters are usually less than 0.1 mg/l. high levels of ammonia can be indicated the presence of contamination of organic materials derived from domestic waste, industrial waste, and agricultural fertilizer runoff. if it refers to effendi’s opinion, it is indicated that the ammonia value exceeding 0.1 mg/l at the l4 site (canal bukit baru) comes from domestic waste and also agricultural fertilizer runoff. the high level of nitrates and nitrites in water is determined by the nitrogen and oxygen compounds described by the bacteria. nitrite in large amounts will bind oxygen in the water resulting in water deprived of oxygen so that dissolved oxygen content becomes low. the content of nitrite can be caused by the degradation of n-containing compounds such as proteins by the activity of micro-organisms. based on table 1 shows that the nitrite and nitrate values are still below the established standard. fe (iron) and mn (manganese) high at sand mining sites may be caused by the release of these minerals when sand mining is done [18]. based on the data shown in table 1 shows that the high fe values precisely at the location of l3 and l5 which is the upstream direction of the river. while the mn values are high at locations l3 and l4. it is possible that the source of fe and mn production from this location is not from the impact of sand mining but from other sources. based on the above sand mining does not contribute significantly as a major contributor to decreased quality of river water chemistry. this may occur because of the mine which was a bit far from the sampling point. in addition, it is estimated that the main sources of pollution from water quality decline are domestic and agricultural waste. the status of the water quality of the lambidaro river based on the evaluation of the pollution index value is shown as listed in table 2. the results of analysis of water chemical characteristics at 5 points of water quality measurement of the river shows that on the part close to the estuary of the river is in good condition indicating that the location is environmentally sustainable. meanwhile, the upstream to the middle river body is in mild contaminated conditions. this indicates that the river’s environment is contaminated. based on table 2, it can be seen that the quality status of the lambidaro river is generally in a mild contaminant condition. if linked to table 1, the cause of pollution is the high bod and cod values indicated that the source of the pollutants comes from domestic waste as well as agricultural waste. in general, the lambidaro river is classified under mildly contaminated conditions. the condition of the mildly contaminated lambidaro river if linked to a sustainable environment indicates that the lambidaro river environment is not in a sustainable condition. it mean, the lambidaro river is no longer able to maintain the carrying capacity of the environment as a provider of resources for human life. lambidaro river is not able to provide river water under the conditions specified quality standards. meanwhile, field studies show that people use river water to meet their daily needs, such as washing, bathing, and latrines. if this condition continues, it will certainly lead to a decrease in the quality of river water, it will also affect the disruption of public health conditions that use water for daily purposes. good environmental management must be done, that the quality of the river water is below the established standard, so it is feasible to be used in everyday life. the things that can be done is to start by reducing the waste that can enter the water body. management of domestic waste can be done by no longer dispose of waste into water bodies. meanwhile, to overcome agricultural waste is to reduce the use of chemicals. good environmental management will certainly have an impact on the achievement of a sustainable environment. table 2. water quality status of lambidaro river [7,8] location pollution index water quality status l1 0.703 good condition l2 1.108 medium contamination l3 0.683 good condition l4 1.133 medium contamination l5 1.4 medium contamination rahmi et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 23-26 doi: 10.26554/ijems.2017.1.1.23-2626 4. conclusion the study of the chemical characteristics of the lambidaro river shows that in general the quality of the water is mildly contaminated. the bod and cod parameters at some point of measurement indicate a value that is above the required water quality standard. indication of the high value of bod and cod comes from domestic waste and agricultural waste. this suggests that sand mining is not a major factor in pollution of the lambidaro river because it is located quite far from the estuary of river. however, it is undeniable that continuous mining will be one of the causes of river pollution. based on the analysis obtained that environmental conditions are polluted, then the management of the environment must be done. this is so that the water quality of the river is below the water quality standard intended. if environmental management has been done, it is expected to achieve a sustainable river environment. thus the community along the lambidaro watershed as a water user can use it because the water condition is in good condition (not polluted). references [1] pangestu, h. and haki, h. 2013. the analysis of total sediment transport on the dawas river district of musi banyuasin. journal of civil and environmental engineering.1(1). pp 103-109. [2] government regulation about the river. number 38. 2011 [3] galunder, b.k. and kolar. m. 2010. chemical analysis and the river mura water quality. international journal of sanitary engineering research. 4(2). pp 4–17. [4] pitchaiah, p.s. 2017. impacts of sand mining on environment–a review. ssrg international journal of geo informatics and geological science. 4(1). pp 1–6. [5] anggraini, 2013. the effect of sand mining on environment quality in regency of tasikmalaya district. antology of geography education. 3(1). pp 1-13. [6] government regulation about management of water quality and control of water pollution. number 82 in 2001. [7] environmental agency of palembang city. strategic environmental assessment power support and capacity of lambidaro river. palembang. 2016. [8] the decision of the minister of the environment about the determination of the status of water quality guidelines. number 115. 2003. [9] endah praptiani. report of palembang city river. 2012. (https://www.academia.edu/9773539/laporan_sungai_ anak_sungai_kota_palembang_2012) accessed on 04 august 2012. [10] documents feasibility study sand mining of panji mahakarya company. [11] suhartini. the phenomenon of sand mining and development and its environmental impact (case study around merapi and bantul district). pp 228-238. presented at the national seminar of mathematics and natural sciences uny, yogyakarta on august 1, 2006 [12] prasad, k., hari, c., anjali, m., reddy. s. 2016. study of physico-chemical characteristics of penna river at chennur, cuddapah basin, india. indian journal of advances in chemical science. 4(1). pp 20-24. [13] simajuntak, m. 2007. dissolved oxygen and apparent oxygen utilization in bay of klabat waters, bangka island. marine science. 12(2). pp 59-66. [14] chandra, s. 2011. evaluation of physicochemical characteristics of various river water in india. coden ecjhao e-journal of chemistry. 8(4). pp 1546-1555. [15] penn, m. r., pauer, j.j., and mihelcic. j.r. biochemical oxygen demand, environmental and ecological chemistry. vol. ii. (https://www.eolss.net/sample-chapters/.../e6-13-04-03. pdf ). [16] aziz, t. 2013. the influence of addition of tawas al2(so4)3 and chlorine ca(ocl)2 to the characteristics of physical and chemistry of water lambidaro river. journal chemical engineering. 3(19). pp 55–65. [17] mahyudin, s. and prayogo, t.b. 2015. water quality analysis and water pollution control strategy of metro river in kepanjen city, malang regency. j-pal, 6(2). pp 15–114. [18] rizqan, a. 2016. quality status of river water around sand mining areas in batang alai river wawai village south kalimantan. enviroscienteae. 12(1). pp 1-6. title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper the analysis of sheet pile assets management in musi river ratih baniva 1*, maulid m. iqbal 2, heni fitriani 2, 1civil engineering graduate program of sriwijaya university, palembang, indonesia 2civil engineering department, faculty of engineering, sriwijaya university, palembang, indonesia *corresponding author e-mail: baniva_9@yahoo.com abstract sheet pile, located on the bank of musi river in palembang, is the city master plan in the development of palembang city. the construction of the sheet piles in musi river was built from 2006 to 2014 but until now there is no further management on the working sheet piles. the aims of this study were to identify the management status of musi sheet piles and to analyze the damage level that occured in musi sheet piles in palembang. based on the results of the analysis, it can be obtained that the management status of the sheet pile was the authority of bbws sumatera viii as the constructor and the owner of sheet pile assets, and it is planned that there will be a musi sheet pile management program in 2019. sheet piles were in a good condition on the components of pile cap structure, sheet pile, and platform at 16 ilir, 9-10 ulu, 11-14 ulu and sheet pile wall structural components at 11-14 ulu which have a damage percentage of more than 10%. a good conditions were also seen in the supporting structure of the fence which has a damage percentage of 0.28% for 9-10 ulu and 1.45% for 11-14 ulu. sheet pile in minor damaged conditions occured in sheet pile structural components of 10.38% in 11-14 ulu. sheet pile components in good condition, minor damaged condition and moderate damaged condition repairs can be done with preventive maintenance or minor repairs. keywords management status, damage levels, musi sheet pile received: 3 june 2019, accepted: 22 june 2019 https://doi.org/10.26554/ijems.2019.3.2.60-66 1. introduction in the construction of the musi river infrastucture in palembang, on the left and right cli�s of musi river, retaining walls were built with a type of sheet pile constructions. musi sheet pile is a city master plan in the development of palembang city in order to overcome the riverbank scour. according to aurdin (2015) the concept of structuring the bank of musi river was with the arrangement of water front plan in palembang as one of the attempts to restore the water areas to public property and plan space along the banks of the river which is oriented to water by building cli�s or sheet pile along the banks of the musi river. the construction of the sheet piles in musi river was built from 2006 to 2014 and was conducted in stages started from contructing the sheet pile in ilir then continued to ulu. however, until now, there is no further management on the working sheet piles. it is feared that the condition of the damaged buildings can cause the sheet piles break faster than the service life, so that it requires the rehabilitation of the building which means that it costs more. according to the government regulation no. 35 of 1991 concerning the river, one of which is related to the handling of water. this is con�rmed and strengthened again in law number 9 of 2015 concerning regional governments that share the authority to manage facilities and infrastructure to the central, province and district or city governments. in order to �nd the best way to manage sheet pile infrastructure, an agency which is authorized and responsible for managing the sheet pile so that the physical condition of it can function as its service life is needed. this is a challenge for the government in managing sheet pile infrastructure assets so that it can give positive contribution optimally in its development. the aims of this study were to identify the management status of musi sheet piles which involved the concerned and adjusted stakeholders based on the government’s rules and regulation to the sheet pile management. then, the next objective of this study was to analyze the damage level that occured in musi sheet piles in palembang by measuring directly to the �eld so that the value of the existing condition of the sheet pile can be obtained. the limitation of this study was that this study was conducted in 3 locations, 16 ilir, 9-10 ulu and 14 ulu sheet piles by selecting the sheet pile structural component which damage was examined only to the extent of being seen or exposed. https://doi.org/10.26554/ijems.2019.3.2.60-66 baniva et. al. indonesian journal of environmental management and sustainability, 3 (2019) 60-66 1.1 sheet pile sheet pile is a river infrastructure that can withstand the pressure of the surrounding soil, prevent landslides and usually consist of sheet pile walls and supports. the construction of sheet pile walls consists of several sheet piles which are installed into the ground, and form a vertical continuous wall formation which is useful for holding back soil or sloping land. sheet pile consists of prefabricated or pre-cast parts (sri respati, 1995) . sheet pile is a thin, �at, and long vertical wall, it is usually made of steel or concrete material which functions not only to hold the soil but also the water that come into the pit (das, 2011) . the musi sheet pile wall uses cantilever sheet pile that is combined with platform sheet pile. in planning the sheet pile on musi river in palembang, the sheet pile functions as cli� guard, border line between land and river, docks, green open space and road inspection. it is expected that the sheet pile along the banks of the musi river can withstand lateral loads of the ground and external loads in the form of static or dynamic work in the rear area of the sheet pile (aurdin, 2015) . the sheet pile building components in the musi river are more oriented to the dock system where the sheet pile is made not blocking or closing the �ow of groundwater from the inside of the sheet pile so as to enable the hydraulic balance of the left and right of the road especially in the rainy season and �ood. according to (usman, 2009) the maintenance of building components requires serious attention in order to obtain maximum results that are expected to make the building more comfortable with good facilities. in the distribution of musi sheet pile components based on the �eld of structural components, namely pile, sheet pile, pile cap, beam and platform. in analyzing the damage level, a physical damage condition of the sheet pile is needed as the criteria for determining the maintenance of sheet pile. according to circular letter no. 01/se/d/2013 maintenance of river infrastructure and river maintenance in attachment ii classi�cation of river infrastructure conditions are as follows: • good condition, if the damage level is still below 10% (ten percent) of the initial conditions of construction. • minor damage condition, if the damage level is 10% (ten percent) to 20% (twenty percent) of the initial conditions of construction. • moderately damaged condition, if the level of damage is 20% (twenty one percent) up to 40% (forty percent) of the initial conditions of construction. • severe damage condition, if the damage level has exceeded or equals to 40% (fourty percent) of the initial conditions of construction. according to regulation of ministry of public works and public housing number 06/prt/m/2015 the de�nition of operation and maintenance is regulating, implementing, monitoring and evaluating activities to ensure the sustainability of functions and bene�ts of water resources. infrastructure that has been operating will decrease in condition along with the high intensity and frequency of usage. changes in environmental conditions or increased decline in infrastructure conditions are caused by many things. some common causes (hudson et al., 1997) : • limited investment funds for public works produced by infrastructure resulting in quality in accordance with the available budget. • lack of management management systems that use the infrastructure. • there is no preparation of funds for the future. • the infrastructure manager is not responsive to immediately repair the infrastructure when repairing the damage, so that when repaired the damage must be very severe to require even more costs. • there is no awareness of the government that requires infrastructure that is made by the government and also given the ful�llment of community rights. • there is a replacement from the central or regional government for reimbursement of maintenance activities. in handling the condition of the structure that is damaged, the physical maintenance is needed so that the structure in the building can function in accordance with the purpose of its construction. according to circular letter no. 05/se/d/2016 the guidelines for the implementation of river infrastructure op activities and the maintenance of rivers especially for physical maintenance of river buildings, there are three categories of river op guidelines and river infrastructure according to the hierarchy and the nature of their work, namely: • preventive maintenance can be in the form of routine maintenance, periodic maintenance and minor repairs. • corrective maintenance can be in the form of special maintenance where the activity of repairing building damage is below 70% to 50%. • rehabilitative maintenance can be in the form of asset renewal where the activities repair or rebuild the buildings which the performance value is less than 50% or have been destroyed (without exceeding the function or design of the initial performance). 2. experimental section 2.1 study area the study area were located in ilir section, sheet pile in front of 16 ilir market, and in ulu section, sheet piles in 9-10 ulu and 11-14 ulu which were located in the center of palembang, south sumatera. in this case, the construction of sheet pile in musi river in palembang was functioned as cli� reinforcement which was one of the ways to overcome the riverbank scour. these sites were chosen by considering the years of building the sheet piles. here are the di�erent research sites of musi sheet pile that can be seen in figure 1. 2.2 methods the methods used in this study are as follows : 2.2.1 questionnaire this questionnaire method was aimsed to determine the management status of sheet pile in musi river by using primary © 2019 the authors. page 61 of 66 baniva et. al. indonesian journal of environmental management and sustainability, 3 (2019) 60-66 figure 1. study area data which was obtained from the questionnaire results through the agencies related to the construction of the sheet pile in musi river in palembang. this questionnaires were given to 6 (six) related agencies, such as bbws sumatera viii, public works department of palembang city, public works department of south sumatera province, bapeda of palembang city, transportation department of palembang, transportation department of south sumatera. the total number of questionnaires distributed in this study was 18 respondents. the distribution of the questionnaire for each agency was given 3 samples. the distribution of questionnaires that have been distributed and returned can be seen in table 1. table 1. the description of the questionnaire on the respondents no description frequency percentage 1 distributed questionnaire 18 100% 2 returned questionnaire 18 100% 3 failed questionnaire 0 0% 4 questionnaire used 18 100% from table 1, the level of the questionnaire that was distributed and returned had a percentage of 100% so that in this study, all returned questionnaires can be processed into data. it used open-ended questionnaires so that the respondents were able to answer the questionnaires as well as provide the reasons behind them. 2.2.2 field survey this survey method was aimed to get the measurements results of the damage that occured in the components of the sheet pile structure in the �eld. therefore, the results of the existing condition of the sheet pile were visually obtained. the measurement of the damage was done by using boat because of the limited location in the river and tidal water that occured. the instruments used in surveying the damage of the sheet pile components in the �eld were: gps, roll meter, camera, digital caliper, and stationery 2.2.3 analysis phases the analysis used in this study are as follows the analysis of management status of musi sheet pile questionnaire : the method used in identifying this questionnaire was descriptive method in which the questionnaire and the interview were reviewed and adjusted to the applicable regulations, then they were described so that the agencies’ perception related to the management of musi sheet pile were obtained. theanalysisof thedamageofmusisheetpile: the method used in analyzing the damage level was survey method which referred to the guidelines of implementing river infrastructure and river maintenance op activities. furthermore, the steps in analyzing the damage level of the musi sheet pile are as follows: • observing the research sites in 16 ilir, 9-10 ulu and 11-14 ulu sheet pile infrastructures. • measuring the existing condition of the damaged sheet pile directly • taking note of the kinds of damage on the inspection sheet. • measuring the volume of the damage by using this formula: pxlxt (1) where : p = damage length; l = damage width; and t = damage height. in determining the volume of the damage, the formula used was adjusted to the shape of the damage occured. • measuring the percentage of the damage that obtained by using this formula: %damage = damagevolume initislvolume x100% (2) where : damage volume = volume obtained from the results of the measurement of the damage in the �eld; initial volume = volume obtained from the initial dimention of the construction. • classifying 4 (four) categories based on the damage percentage, they were good, minor damage, moderate damage, and severe damage conditions. according to the circular letter no. 01/se/d/2013 about the maintenance of river infrastructure and river maintenance in attachment ii where the damage percentage became the priority scale for the physical mainatance of the sheet pile components. 3. results and discussion 3.1 the analysis of management status of musi sheet pile questionnaire to identify the management status of musi sheet pile, the questionnaires that consisted of 10 (ten) items related to the construction and the management of musi sheet pile were distributed to 6 agencies with total number of the respondents © 2019 the authors. page 62 of 66 baniva et. al. indonesian journal of environmental management and sustainability, 3 (2019) 60-66 figure 2. respondents’ percentage were 18 people. therefore, the results obtained from the respondents can be seen in table 2. in addition, from table 2, table 2. the results of the respondents’ answers items the results of the respondents’ answers yes no 1 18 0 2 5 13 3 4 14 4 4 14 5 17 1 6 18 0 7 1 17 8 4 14 9 18 0 10 11 7 if the results of the respondent’s answer to the questions were included in percentage category of respondents, then it can be seen in figure 2. in �gure 2, the total number of the respondents who answered yes for question one, six, and nine were 100%, meanwhile, the total number of the respondents who answered yes for question three, four, and eight were 22,22%. for the remaining questions, the percentage produced varies, for respondents who answered yes for question two were 27,78%, for question ten were 61,11%, for question �ve were 94,44%, and 5,56% for question seven. the results of this percentage can be described from the respondents’ response. therefore, the information obtained were as follows: • musi sheet pile in palembang is a city master plan in accordance with the spatial plans year 2012-2032. • human resource management department south sumatera province, public works and spatial plans department, bappeda of palembang city, transportation department of palembang and transportation department of south sumatera have roles as the users, meanwhile bbws sumatera viii as the constructor. • musi sheet pile in palembang is owned by bbws sumatera viii. • musi sheet pile inventory has been done by bbws sumatera viii related to the assets ownership and the public works and spatial plans service only because the location is in palembang. • musi sheet pile in palembang functions as the cli� reinforcement. • the management / maintenance needs to be done so that it remains functioning optimally. • the maintenance has not been carried out until now because the operation and maintenance of musi sheet pile is not budgeted in the activity budget plan, but it will be planned for a sheet pile maintenance program in 2019 by bbws sumatera viii. • no coordination has been held regarding the management / maintenance of the musi sheet pile in palembang. the coordination between agencies is only carried out limited to planning and development. • delegation of management of musi sheet pile can be done in deconcentration to the provincial or city governments concerned. • bbws sumatera viii is willing to be given the responsibility of managing the musi sheet pile in palembang because it is in accordance with its authority where the assets are owned by the central government in referring to the regulations, the provisions on management of musi sheet pile have been clearly stated in minister of public works regulation no. 04/prt/m/2015 and law no. 23 of 2014 is the authority of the central government or bbws sumatera viii, but if it is associated with law no. 26 of 2007 concerning spatial planning is made possible by the city government authority. overall, the management of musi sheet pile in palembang is the authority of bbws sumatra viii where in the concept of the strategic plan for the implementation of the 2010-2025 op sda that all sda assets must be op in good condition, minor damaged, and moderately damaged or already completed. this is expected to be able to maintain the condition and function of sheet pile according to the service age. so that it is expected to be able to carry out the operation and maintenance of sheet pile according to the plan. 3.2 the analysis of the damage of musi sheet pile the measurement of damage conditions in each component of sheet pile is obtained from survey information data directly in the �eld by tracing these sheet pile components which will be recorded on a form that is given an inspection record of the component by marking existing / real damage in the �eld accompanied by documentation of damaged parts and description the damage. from the calculation of the percentage of damage that has been done, it can be classi�ed the conditions in each component of the sheet pile structure by referring to se 01/se/d/2013 by clarifying the condition of the sheet pile into four conditions including: good, minor damage, moderately damaged and severe damage conditions. the following are the results of recapitulation of damage calculations that © 2019 the authors. page 63 of 66 baniva et. al. indonesian journal of environmental management and sustainability, 3 (2019) 60-66 have been classi�ed in 3 sample research sites. 3.2.1 16 ilir sheet pile 16 ilir sheet pile which is right in front of 16 market was built in 2006 with a length of 93 meters. after a �eld damage survey was carried out on each component of the structure and supporting structure of the sheet pile, the results of the sheet pile condition were obtained as follows. from table 3, it can be seen that the sheet pile structure of the platform component has the largest percentage of 2.389% and the component structure of the pile cap has the smallest amount of 0.004%. this percentage value was still in the sheet pile category still in good condition because the percentage produced in each component was less than 10%. while in table 4, for supporting structural components on the fence, the condition was moderately damaged because it has a percentage of 21.739 % or more than 20%. 3.2.2 9-10 ulu sheet pile 9-10 ulu sheet pile, located in ulu part between the ampera bridge the temple court, was built in 2007 with the length of 174 meters. this sheet pile has a type of sheet pile with a cross section of the sheet pile in the front. after conducting a damage survey in the �eld on each component of the structure and supporting structure on the sheet pile, the results of the sheet pile condition were obtained as follows. from table 5, the highest percentage of structural damage was found in the components of the platform structure of 2.892% and the lowest percentage value was in the pile component of 0.003%. whereas the value of the percentage of damage to the supporting structure of the fence has a percentage of 1.452%. so that from these results the structural components and structural components of the plaster support were in good condition. 3.2.3 11-14 ulu sheet pile 11-14 ulu sheet pile was an advanced plaster built in 2013 and has a length of 83 meters. after a �eld damage survey was carried out on each component of the structure and supporting structure of the sheet pile, the results of the sheet pile condition were obtained as follows: from table 6, it can be seen for the supporting structure components on the fence having a damage percentage of 4.821% and for the components of the pile structure, the pile cap and platform have a percentage of less than 10% or in good condition. in contrast, in table 7 the structure of the sheet pile wall component was 10.387% or minor damaged. 3.3 discussion damage to components in sheet pile in the musi river is caused by several factors including the high tide of river water, garbage piles, ship or boat backrest and a lack of attention in managing sheet pile on the musi river. this causes damage to the sheet pile components so that in the handling e�ort it is necessary to maintain each component of the sheet to support the optimal sheet pile function. maintenance can be carried out by the asset management body in accordance with the activity budget plan by considering the damage to the sheet pile component that occurs so that the consistency of the sheet pile function. 4. conclusions the conclusions of this study are: • from the results of the sheet pile management status identi�cation it can be concluded that the management of musi sheet pile in palembang was the authority of bbws sumatra viii as the constructor and owner of the sheet pile assets and will be planned for the musi sheet pile maintenance program in 2019. • sheet pile in good condition occured in components of the structure of pile cap, pile, platform, at 16 ilir, 9-10 ulu, 11-14 ulu and sheet pile wall structural components at 11-14 ulu which have a damage percentage of more than 10% • good conditions were also seen in the supporting structure of the fence which has a damage percentage of 0.28% for 9-10 ulu sheet pile and 1.45% for 14 ulu sheet pile. • sheet pile in minor damaged conditions occured in sheet pile structural components of 10.38% in 11-14 ulu. • sheet pile components in good condition, minor damaged condition and moderate damaged condition repairs can be done with preventive maintenance or minor repairs. 5. acknowledgement acknowledgements for government agencies namely balai besar wilayah sungai sumatera viii references aurdin, y. (2015). sheet pile design to overcome the scour of musi river 600 meters long of seberang ulu (kampung kapiten-musi ii bridge) in palembang. teknika journal, 2(2) das, b. (2011). principles of foundation engineering (4th ed.). pws publishing company. hudson, w., r. haas, and w. uddin (1997). infrastructure management. mcgraw-hill, new york localgoverment (1991). government regulations number 35 year 1991 concerning the river localgoverment (2007). constitution number 26 year 2007 localgoverment (2014). constitution number 23 year 2014 localgoverment (2015). constitution number 9 year 2015 pupr (2013a). public works ministry of the republic of indonesia, attachment ii, maintenance of river infrastructure and river maintenance, circular letter of public works ministry number 01/se/d/2013. technical report, directorate general of water resources, jakarta pupr (2013b). public works ministry of the republic of indonesia, guidelines of implementing the operational activity and maintaining river infrastructure and river main© 2019 the authors. page 64 of 66 baniva et. al. indonesian journal of environmental management and sustainability, 3 (2019) 60-66 table 3. percentage of sheet pile components in good condition field component unit initial volume damage volume damage percentage structure pile cap m3 325.50 0.01 0.004 pile m3 1131.53 0.17 0.015 platform m3 404.55 9.67 2.389 sheet pile wall m3 55.8 0.67 1.207 table 4. the percentage of sheet pile components in moderate condition field component unit initial volume damage volume damage percentage supporting structure fence m3 184 40 21.739 table 5. the percentage of good sheet pile component field component unit initial volume damage volume damage percentage structure pile cap m3 366.14 0.02 0.004 pile m3 1534.52 0.05 0.003 platform m3 1534.52 0.05 2.892 sheet pile wall m3 174.35 0.52 0.298 supporting structure fence m3 4.97 0.07 1.452 table 6. percentage of sheet pile components in good condition field component unit initial volume damage volume damage percentage structure pile cap m3 216.72 1.28 0.591 pile m3 664.68 0.19 0.028 platform m3 103.2 0.98 0.946 supporting structure fence m3 3.13 0.15 4.821 table 7. the percentage of the sheet pile component in minor condition field component unit initial volume damage volume damage percentage structure sheet pile wall m3 68.8 7.146 10.387 © 2019 the authors. page 65 of 66 baniva et. al. indonesian journal of environmental management and sustainability, 3 (2019) 60-66 tainance, circular letter of public works ministry number 05/se/d/2016. technical report, directorate general of water resources, jakarta pupr (2015a). regulation of ministry of public works and public housing of the republic of indonesia, number 04/prt/m/2015 concerning criteria and river basin determination. pupr (2015b). regulation of ministry of public works and public housing of the republic of indonesia, number 06/prt/m/2015 concerning exploitation and maintenance of water resources and irrigation buildings. sri respati, n. (1995). foundation. pt. penerbit pusat pengembangan pendidikan politeknik, bandung usman, k. (2009). management review of building maintenance in lampung university. university of lampung © 2019 the authors. page 66 of 66 introduction sheet pile experimental section study area methods questionnaire field survey analysis phases results and discussion the analysis of management status of musi sheet pile questionnaire the analysis of the damage of musi sheet pile 16 ilir sheet pile 9-10 ulu sheet pile 11-14 ulu sheet pile discussion conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper emission and heavy metal content characteristic of densified refused derived fuels of oil sludge and biomass combination as an alternative fuel for cement plant rati yuliarningsih1*, fadjar goembira1, puti sri komala1, nino perdana putra2 1master program of environmental engineering, universitas andalas, padang-west sumatera, indonesia 2clinker production department, semen padang, padang-west sumatera, indonesia *corresponding author e-mail: ratiyuliarningsih12@gmail.com abstract hazardous waste such oil sludge combined with biomass (coconut shell and rice husk) was utilized as an alternative fuel in cement plant in form of densified-refused derived fuel (d-rdf). d-rdf were co-processed with primary fuel into rotary kiln in order to reduce usage of fossil fuel and eliminate the hazardous waste by thermal treatment, meanwhile to recover the energy contained in the d-rdf, the utilization of these waste are expected without causing adverse effect into the environment. co-processing of d-rdf as alternative fuels into cement plant kiln must follow the regulation applied in indonesian environment and forestry minister regulation 19/2017 and european union for responsible incineration and treatment of special waste (eurits). based on previous research, d-rdf composition of oil sludge and biomass at 1:1 ratio with 5% starch addition was choose as they give best calorific value at 6000 kcal/kg. the objectives of this research are to observe the emission caused by the utilization of these d-rdf and potential effect into cement or clinker product. the result show nox and co value are meet the standard requirement by government regulation meanwhile so2 value which are 1251 mg/nm3 and 1500 mg/nm3, over the regulation standard which is 650 mg/nm3. this issue could be overcome in the plant with pretreatment of d-rdf and utilization of bag house filter or electrostatic precipitator before release the emission to the stack. trace element analysis of d-rdf ashes (as, cd, co, cr, cu, hg, mn, ni, pb, se, sn dan zn) show the result are meet the eurits regulation, which mean utilization of d-rdf will not give quality defect to cement or clinker product keywords emission, oil sludge, biomass, hazardous waste, d-rdf received: 27 agustus 2019, accepted: 26 september 2019 https://doi.org/10.26554/ijems.2019.3.3.100-105 1. introduction the cement production process is an intensive thermal process because it requires high temperatures in the clinkerization process so it requires a lot of fuel. the cement industry uses 20 – 40 % of the total production cost as fuel cost (hajinezhad et al., 2016). to reduce dependence on fossil fuels, efforts have been made to substitute fuels with alternative fuels through a co-processing process with the use of waste and biomass. one of alternatives energy available and considered by pt semen padang is the use of oil sludge waste, which received from pt pertamina in the range of 20 tons/month to be destroyed in a rotary kiln in the cement plant. oil sludge is a solid waste in the form of black mud or paste, sometimes mixed with soil, gravel, water and other materials produced from the refining process, distribution process and petroleum storage tanks. oil sludge contains hydrocarbon compounds such as benzene, toluene, ethyl benzene, xylenes, and heavy metals (hu et al., 2013). utilization of oil sludge as fuel must meet emissionquality standards in accordance with the indonesian environment and forestry minister regulation 19/2017, meanwhile the trace element of d-rdf must meet the quality standards of the european union for responsible incineration and treatment of special waste (eurits) for utilization of waste co-incineration in cement kilns. a large number of environmental feasibility tests have been carried out to understand the characteristics of emissions and ash by burning d-rdf as fuel in mass combustion. to our knowledge, there has been little research on the utilization of oil sludge as an alternative fuel in cement production. in addition, there are only a few studies on the effects of various modes of adding oil sludge on clinker https://doi.org/10.26554/ijems.2019.3.3.100-105 yuliarningsih et. al. indonesian journal of environmental management and sustainability, 3 (2019) 100-105 quality (huang et al., 2017). biomass can be considered as an almost co2 neutral fuel (hughes, 2000), although there are still emissions associated with harvesting, transportation, pre-treatment, etc. in addition, biomass combustion prevents the release of methane (ch4) from residues, considering that ch4 has a 21 times higher effect as a potential cause of global warming compared to co2. in addition, alkaline ash from biomass can capture some co2 gas from burning (saidur et al., 2011). most biomass fuels contain less sulfur. therefore, cofiring with coal usually results in lower so2 emissions (ren et al., 2017). nox emissions arise from atmospheric nitrogen and from nitrogen-bound fuels, which are released during the volatilization and char oxidation phases. the release of volatile substances from biomass combustion is higher than that of coal, and during this phase, the nitrogen in the fuel is volatilized into the flame as volatile matter (lau and niksa, 1993). inside the flame, nitrogen bound to biomass mostly forms nh3 instead of hcn which is usually formed by nitrogen coal, and this can help prevent the formation of nox in flames (hein and spliethoff, 1999). previous studies on coal combustion and rice husk jun xie et al. (2007) reported that in the use of coal ratio remained the same and addition amount of biomass into the mixture will reduced no emissions but slightly increased so2 emissions. no reduction is associated with a lower terminal velocity of rice husk particles than coal particles, due to differences in density (fang et al., 2004). other research was combines coal and municipal solid waste (msw) into circulating fluidized bed (cfb) (desroches-ducarne et al., 1998). the results showed that acid gas flue increased as the proportion of msw increased, and, further, sox decreased because the amount of hcl in the flue gas increased. figure 1. (a) d-rdf(a) dan (b) d-rdf(b) in this study, d-rdf consisting of oil sludge and biomass waste is burned in the furnace to investigate the feasibility of burning d-rdf emissions. the properties of volatile matter, ash content, pollutant emissions and metal content for various fuel ratios are analyzed and discussed in this study. 2. experimental section 2.1 materials for the manufacture of d-rdf in this study, oil sludge is mixed with two types of biomass wastes, which are coconut shell powder and rice husk. the d-rdf sample can be categorized into two groups namely d-rdf (a) containing oil sludge, coconut shell powder, and 5% starch and d-rdf (b), where coconut shell powder is replaced with rice husk. for the characteristics of d-rdf raw materials can be seen in table 1. 2.2 equipment and experimental in this study, the d-rdf was produced using oil sludge as a base material and combined with coconut shell powder or rice husk with a composition of 1:1, then 5% starch is used as an adhesive to bind the raw materials. further, raw materials are mixed in a mixer and then feed into pelletizer machine to form d-rdf. the d-rdf forms produced were cylindrical with a length of 10-16 mm, and a diameter of 5 mm. for visual form of combination of d-rdf (a) and d-rdf (b) can be seen in figure 1. figure 2. d-rdf emission measurement scheme to measure co, so2, nox emissions from this d-rdf, it is carried out with a combustion scheme as shown in figure 2. probes from the portable gas emissions analyzer are inserted into the stack furnace. 1 gram d-rdf prototype was burned in the furnace for 1 minute. the furnace temperature is set at a temperature of 1000 oc then gas so2, nox, and co, co2, measured by the gas emission analyzer directly and the value (ppm) will be seen on the screen of the gas emission analyzer. the d-rdf residue after combustion then analyzed for their metal content using a shimadzu icpe 9000tm tool. the results of the emissions analysis and metal content are compared with quality standards in the indonesian environment and forestry minister regulation 19/2017 and eurits. 2.3 methods test of calorific value of raw materials and d-rdf was carried out using the calorimeter bomb tool with the astm d 2015: standard test method for gross calorific value of solid fuel by the adiabatic bomb calorimeter. moisture content, ash content, volatile matter, and fixed carbon content were measured using astm d3173 standard methods. ultimate analysis using thermo scientific chns / o tools with astm method d5373-16: determination of carbon, © 2019 the authors. page 101 of 105 yuliarningsih et. al. indonesian journal of environmental management and sustainability, 3 (2019) 100-105 table 1. d-rdf raw material and additive characteristic parameter unit raw material additive oil sludge coconut shell rice husk starch proximate analysis moisture % 34.88 10.94 10.83 13.94 volatile matter % 76.13 68.08 57.44 81.39 ash content % 3.14 1.55 18 0.116 fixed carbon % 1.17 19.8 14.34 3.52 calorific value kcal/kg 6298.86 4333.97 3381.91 3528.22 ultimate analysis (% dry basis) carbon (c) % 74.49 50.04 41.17 39.91 hydrogen (h) % 12.4 6.33 5.63 6.78 nitrogen (n) % 0 0.11 0.3 0 oksigen (o) % 8.73 41.97 35.04 50.24 sulfur (s) % 0.62 0.12 0.1 0.15 table 2. air emission limits at cement plants that implement hazardous waste co-processing based on regulation applied. parameter unit quality standard co mg/nm3 3000 so2 mg/nm3 650 nox mg/nm3 800 (source: indonesian environment and forestry minister regulation 19/2017) hydrogen, and nitrogen in analysis of samples of coal and coke for measuring c, h, and n content. astm d 4239-17: sulfur in the analysis sample of coal and coke is used to measure s content and astm d 3176-16: ultimate analysis of coal and coke is used to measure o content. analysis of metal content in waste oil sludge was carried out using astm d7260-19: standard practice for optimization, calibration, and validation of inductively coupled plasma-atomic emission spectrometry (icp-aes) for elemental analysis of petroleum products and lubricants. the oil sludge sample is dissolved first using an acid digestion method (nitric acid), then the solution will be analyzed by icp-aes which will measure the energy intensity of radiation emitted by the elements that experience changes in atomic energy levels (excitation or ionization). in indonesia, cement plants that utilize rdf co-processing and other hazardous wastes are subject to regulations issued by the indonesian environment and forestry minister regulation 19/2017 which sets co, so2, and nox emission limits as shown in table 2. the term trace element heavy metal has been used extensively as a term that describes the shape of certain metals. based on research yang et al. (2019), the characteristics of the heavy metal group are as follows: table 3. physical characteristic of d-rdf parameter unit d-rdf combination d-rdf(a) d-rdf (b) density g/cm3 0,9562 0,7466 length mm 15 10 diameter mm 5 5 drop test % 94 77 • has very large specific gravity (more than 4) • has atomic numbers 22-34 and 40-50 as well as lanthanide and actinide elements • has a specific (specific) biochemical response to living organisms. unlike ordinary metals, heavy metals usually have special effects on living things. it can be said that all heavy metals can be toxic materials that will poison the bodies of living things. examples are mercury metal (hg), cadmium (cd), lead (pb) and chromium (cr). in general, trace elements will enter the clinker in several forms: (1) in solid solutions with various phases of calcium silicate and calcium aluminate; (2) as a substitute atom that can damage the crystal structure of these phases, such as when cobalt replaces aluminum in afm; (3) physically adsorbed on the surfaces of various phases as insoluble hydroxides, sulfates, or carbonates; and (4) as a precipitated mineral that is mixed with the final product, such as when molybdenum is formed forming powellite (camoo4) at relatively high concentration of molybdenum (horsley et al., 2016). the quality of the final product such as clinker and cement must be controlled in accordance with applicable national or international quality standards. in principle, rdf co-processing should not reduce the quality of cement produced, where clinkers cement or concrete produced may not be used as a heavy metal dump. apart from that, there © 2019 the authors. page 102 of 105 yuliarningsih et. al. indonesian journal of environmental management and sustainability, 3 (2019) 100-105 table 4. chemical characteristic of d-rdf parameter unit d-rdf lignitec d-rdf (a)a d-rdf (b)b moisture % 9,8 11,25 volatile matter % 73,91 69,15 49,9 ash content % 2,99 12,49 11,5 fixed carbon % 13,33 7,11 38,6 calorific value kcal/kg 6413,17 6063,38 6 carbon (c) % 66,4 52,2 63,92 hydrogen (h) % 8,65 7,19 4,25 oksigen (o) % 21,56 20,38 17,71 nitrogen (n) % 0,03 0,01 1,51 sulfur (s) % 0,32 0,22 1,11 note : d-rdf (a) = oil sludge : coconut shell (1:1) ; d-rdf (b) = oil sludge : rice husk (1:1) ; source : (yanik et al., 2018) should be no negative impact on the environment. 3. results and discussion 3.1 physical characteristic of d-rdf combination physical characteristics of d-rdf combination; d-rdf (a) and d-rdf (b) can be seen in table 3. based on table 3 it can be seen that both combination of d-rdf (a) (oil sludge: coconut shell) and d-rdf (b) (oil sludge : rice husk) have similar diameter and the length are in range 10 – 15 mm. by observing the density and drop test value it show that d-rdf (a) has better physical characteristics when compared to the d-rdf (b) because it more solid and compact. 3.2 chemical characteristic of d-rdf combination as a comparison to these d-rdf the chemical properties of lignite coal from the previous research yanik et al. (2018) as shown in table 4. while compared to nitrogen and sulfur content of lignite, both combination shows that nitrogen and sulfur content are below lignite. these are mean that the source of nox and so2 formation from combustion are lower than what lignite potentially contributes. while compared sulfur sources (s) from oil sludge as raw material that is equal to 0.62%, sulfur (s) values in both d-rdf variations tend to be smaller because the addition of biomass (coconut shell and rice husk) are reducing s content within the d-rdf. 3.3 emission from combustion in all cement plants, whether using d-rdf or not, dust (particulate), co, nox, and so2 emissions are the main emissions that need to be addressed. 3.4 carbon monoxide (co) in this study, co combustion values from d-rdf variations and compare with lignite combustion emission can be seen in figure 3. in the combustion of these d-rdf variations, it can be seen that co from the d-rdf (a) value indicates as the highest value when compared with other compositions. however, both compositions of d-rdf (a) and (b) in regards to co emission are meeting the applicable quality standard. co gas is formed due to lack of oxygen in the combustion process, imperfect mixing between oxygen and fuel in the combustion chamber and rapid cooling of the combustion product to lower than the ignition temperature of co gas so that incomplete combustion occurs. co can be formed accidentally and anywhere in the kiln system. co gas emissions usually indicate fuel that is partially burned and not fully utilized. figure 3. co emission of d-rdf and lignite figure 3.5 sulfur dioxide (so2) so2 emission from d-rdf and lignite combustion could be seen in figure 4. sulfur dioxide (so2) is the result of oxidation of sulfides or sulfur elements contained in fuels during combustion and this gas is colorless with a sharp odor. the emission range depends on the content of volatile sulfur compounds in the raw material; mostly below 300 mg / nm3; although sometimes up to 3000 mg / nm3 (unep, 2011). indirect combustion, so2 emissions of lignite coal showed the highest value of 16,588 mg / nm3 when compared with © 2019 the authors. page 103 of 105 yuliarningsih et. al. indonesian journal of environmental management and sustainability, 3 (2019) 100-105 other d-rdf compositions. however, based on government quality standards through the minister of environment and forestry regulation of the republic of indonesia, number 19/2017, all samples both d-rdf and coal all show values above the applicable quality standard of 650 mg / nm3 as shown in figure 4. figure 4. comparison of so2 emissions from d-rdf composition with lignite coal to reduce so2 content, several methods can be used including (horkoss, 2008): • reduction of sulfur content, based on the goal of a substitution strategy by reduces inputs to reduce output. • optimizing the clinker combustion process, conducted to reduce heat consumption, to improve clinker quality and to increase equipment life. so2 emission reduction is only a side effect of optimization. • adding ca(oh)2 to the upper stage preheater, in order as an so2 absorbing reagent, hydrated lime can be injected into the right location in the upper stage preheater where hydrated lime reacts with so2 directly. 3.6 nox emission for nox value from d-rdf and lignite combustion could be seen in figure 5. nitrogen oxide (nox) is a group of nitrogen gases found in the atmosphere consisting of nitrogen monoxide (no) and nitrogen dioxide (no2). air pollution by nox gas can cause the emergence of peroxy acetyl nitrates which is abbreviated with pan. peroxy acetil nitrates causes irritation in the eyes which causes the eyes to feel sore and runny. in combustion units, nitrogen oxides (nox) mainly arise from three sources, namely, thermal, prompt, and fuel sources. the formation of nox is one of the major concerns because its emission would further induce acid rain, photochemical smog, and even health hazards (li et al., 2018). based on figure 5, the standard quality of nox value is 800 mg / nm3 meanwhile the results for d-rdf (a) and drdf (b) are still far below the applicable quality standards which are 143 mg / nm3 and 69 mg / nm3, respectively. this is due to the low content of nitrogen (n) composition ranging from 0.01 to 0.03%. when compared to lignite coal, the nox emission caused by lignite is higher, this is due to the lignite coal its nitrogen content is quite high at 1.51%. figure 5. comparison of nox emission from d-rdf composition with lignite coal 3.7 heavy metal content of d-rdf ash for the results of trace element analysis of heavy metals of d-rdf (a) and d-rdf (b) can be seen in table 5. the results of both d-rdf for heavy metal content analysis were compared with the quality standard in fuels according to eurits shows that there was no heavy metal in the drdf that exceeded the specified quality standard. whereas in other studies edo et al. (2017) with the composition of demolition and construction wood (dc): rdf, it was found that there was an analysis of metal content that exceeded the applicable metal content, namely for as and pb metals. this result shows that d-rdf from the of oil sludge: biomass waste combination is considerable suitable as an alternative fuel in cement industry. 4. conclusions in this study, an observation was made for the emissions resulting from the utilization of d-rdf mixture of oil sludge and biomass as an alternative fuel in the cement industry as well as the metal content of combustion residual ash. the results of this study are compared with the use of lignite coal as the main fuel for combustion in the cement industry. the co content shows that both d-rdf have higher emission values than lignite, but still meet the applicable quality standards. both of so2 content of d-rdf even though it is above the quality standard but is far below the result of lignite combustion, this is will make the workload of emission control devices such as esp and bag house filters will be lower to reduce levels of so2 emissions in the utilization of d-rdf compared to lignite utilization. in the case of nox content, both d-rdf and lignite show that nox emission values are meet applicable emission standards. the content of the combustion ash metal shows that the d-rdf metal content meets applicable quality standards. meaning that the utilization of d-rdf as an alternative fuel will not affect the quality of the clinker and cement produced. © 2019 the authors. page 104 of 105 yuliarningsih et. al. indonesian journal of environmental management and sustainability, 3 (2019) 100-105 table 5. analysis of d-rdf (a) and d-rdf (b) heavy metal content parameter unit standarda d-rdf (a) d-rdf (b) as mg/l 10 0,0238 0,0227 cd mg/l 10 0,0340 0,0354 co mg/l 200 0,126 0,131 cr mg/l 200 0,047 0,049 cu mg/l 200 0,044 0,047 hg mg/l 2 0,078 0,087 mn mg/l 200 0,052 0,055 ni mg/l 200 0,024 0,021 pb mg/l 200 0,023 0,022 se mg/l 10 0,021 0,02 sn mg/l 200 0,054 0,054 zn mg/l 500 0,289 0,30 references desroches-ducarne, e., e. marty, g. martin, and l. delfosse' (1998). co-combustion of coal and municipal solid waste in a circulating fluidized bed. fuel, 77(12); 1311–1315 edo, m., n. skoglund, q. gao, p.-e. persson, and s. jansson (2017). fate of metals and emissions of organic pollutants from torrefaction of waste wood, msw, and rdf. waste management, 68; 646–652 fang, m., l. yang, g. chen, z. shi, z. luo, and k. cen (2004). experimental study on rice husk combustion in a circulating fluidized bed. fuel processing technology, 85(11); 1273–1282 hajinezhad, a., e. z. halimehjani, and m. tahani (2016). utilization of refuse-derived fuel (rdf) from urban waste as an alternative fuel for cement factory: a case study. nt. j. renew. energy res. e.z.halimehjani al, 6(2) hein, k. and h. spliethoff (1999). co-combustion of coal and biomass in pulverized fuel and fluidized bed systems–activities and research in europe. univ. of stuttgart (de) horkoss, s. (2008). reducing the so2 emission from a cement kiln. international journal of natural and social science horsley, c., m. h. emmert, and a. sakulich (2016). influence of alternative fuels on trace element content of ordinary portland cement. fuel, 184; 481–489 hu, g., j. li, and g. zeng (2013). recent development in the treatment of oily sludge from petroleum industry: a review. journal of hazardous materials, 261; 470–490 huang, m., x. ying, d. shen, h. feng, n. li, y. zhou, and y. long (2017). evaluation of oil sludge as an alternative fuel in the production of portland cement clinker. construction and building materials, 152; 226–231 hughes, e. (2000). biomass cofiring: economics, policy and opportunities. biomass bioenergy, 19; 457–465 jun xie, j., x. min yang, l. zhang, t. li ding, w. li song, and w. gang lin (2007). emissions of so2, no and n2o in a circulating fluidized bed combustor during co-firing coal and biomass. journal of environmental sciences, 19(1); 109–116 lau, c. and s. niksa (1993). the impact of soot on the combustion characteristics of coal particles of various types. combustion and flame, 95(1-2); 1–21 li, p.-w., c.-s. chyang, and h.-w. ni (2018). an experimental study of the effect of nitrogen origin on the formation and reduction of nox in fluidized-bed combustion. energy, 154; 319–327 ren, x., r. sun, x. meng, n. vorobiev, m. schiemann, and y. a. levendis (2017). carbon, sulfur and nitrogen oxide emissions from combustion of pulverized raw and torrefied biomass. fuel, 188; 310–323 saidur, r., e. abdelaziz, a. demirbas, m. hossain, and s. mekhilef (2011). a review on biomass as a fuel for boilers. renewable sustainable energy rev, 15; 2262–2289 unep (2011). annual report. technical report 978-92807-3244-3 yang, j., q. li, j. zhao, y. zhao, and j. zhang (2019). sorbents for trace elements in coal-derived flue gas. in emission and control of trace elements from coal-derived gas streams. elsevier, pages 287–373 yanik, j., g. duman, o. karlström, and a. brink (2018). no and so2 emissions from combustion of raw and torrefied biomasses and their blends with lignite. journal of environmental management, 227; 155–161 © 2019 the authors. page 105 of 105 introduction experimental section materials equipment and experimental methods results and discussion physical characteristic of d-rdf combination chemical characteristic of d-rdf combination emission from combustion carbon monoxide (co) sulfur dioxide (so2) nox emission heavy metal content of d-rdf ash conclusions title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper box behken design for optimization of cod removal from palm oil mill effluent (pome) using reverse osmosis (ro) membrane muhammad said1*, muneer m. ba-abbad2, siti rozaimah sheikh abdullah3, abdul wahab mohammad3,4 1department of chemistry, faculty of mathematics and science,sriwijaya university, indralaya, 30662,sumatera selatan, indonesia 2department of chemical engineering, faculty of engineering and petroleum, hadhramout university of science &technology, mukalla, hadhramout, yemen 3department of chemical and process engineering, faculty of engineering and built environment, universiti kebangsaan malaysia, 43600 bangi, selangor, malaysia 1research centre for sustainable process technology, faculty of engineering and built environment, universiti kebangsaan malaysia, 43600, bangi, selangor, malaysia *corresponding author e-mail: saidusman2011@gmail.com abstract the optimization of cod removal from palm oil mill effluent (pome) using the reverse osmosis (ro) membrane was investigated. experimental conditions for reduce the cod value of pome were achieved successfully using the box behken design. the values of affecting factors (pome concentration, ph and transmembrane pressure were optimized according to the polynomial regression model. the predicted conditions to produce lower cod values were found to be pome concentration (vol. %) =28.30, ph =10.75 and transmembrane pressure= 0.69 kpa. the predicted of cod value was 24.137 mg/l which in good agreed with experiment value as 25.763 mg/l was obtained. keywords pome, ro membrane, box behken, cod received: 18 february 2019, accepted: 1 march 2019 https://doi.org/10.26554/ijems.2019.3.1.39-46 1. introduction palm oil mill effluent (pome) has been reported as a main wastewater produced from industry of palm oil mill. the main process of crude palm oil extraction from fruit is required to use huge amount of water which estimated 5-7.5 tons of water for produce of 1 tons of crude palm oil. unfortunately, more than 50% of the water has been produced as pome which causes to contaminate the environment (ahmad, 2003). the common method to handle pome is an integrated anaerobic and aerobic pond which disadvantages large area and long residence times have been reported earlier (yejian, 2008). last few years, some of previous studies are trying to still this problem by including biological and physical-chemical (chan, 2010; mohammed, 2014; shak, 2014). recently, the new method of membrane technology has been applied for pome treatment which improved the quality of final process effluents (said, 2005). the application of membrane especially reverse osmosis (ro) for pome treatment has many advantages such as capability to produce clear water in relatively short amount of time, small area and energy consumption. higher efficiency to reduce many parameters related to pome treatment process quality such as bod, cod, and, tss to acceptable levels set by regulatory agency (ahmad, 2006; wu, 2010). effects of several parameters such the pressure and concentration on the pome treatment have been investigated experimentally for each parameter which led to increase the experiment runs and consuming time (wu, 2007). in carrying out an experiments pome treatment which containing many affect variables, a tool such as response surface methodology (rsm) is required to optimize the process response (mohajeri, 2010). the response surface methodology (rsm) has been applied as a statistical technique to study of affecting process variables and build of experimental model with interactive variables (muneer, 2013b). as main advantages to apply rsm is, the higher interaction between all process variables and lower runs of experiment which attributed to consuming time of the process compared the traditional optimizations (box and draper, 1987). for this propose, the box behken design with lowest run of experiment has been selected for other chemical process which exhibited more efficient and accurate for the final process response (ismail, 2005). the https://doi.org/10.26554/ijems.2019.3.1.39-46 said et. al. indonesian journal of environmental management and sustainability, 3 (2019) 39-46 figure 1. experiment stages of pome treatment process main objective of this work is to investigate the ability of rsm based on the box behken design to optimize the affected process variables to reduce the cod using reverse osmosis (ro) membrane. 2. experimental section 2.1 materials and method raw pome was collected from a local palm oil mill in selangor, malaysia. to adjust of pome ph within the treatment process, sodium hydroxide and hydrochloric acid from r & m chemical, malaysia and merck company respectively, were used. the pome treatment process consists of two main stages as the first pre-treatment and second optimization was designed as shown in fig. 1.the first stage of pre-treatment includes adsorption and ultrafiltration membrane (uf) was used to reduce suspended solids from the raw pome. about 10 l contains different volume % (vol. %) of raw pome concentration was feed to adsorption column using dosing pump under constant flow rate at 2 ml/min. the pome flows downward along gravity, and exits at the bottom of the column which was feed into the uf membrane. the ultrafiltration pretreatment were carried out in cross flow unit with a hollow fiber membrane. permeate from the uf membrane also simultaneously serves as feed into the ro membrane. in the stage of ro membrane, the pome feed was pumped through a spiral wound (re2012-lpf, csm filter) and recycled back to the uf feed reservoir. the cod values of the pome feed sample and permeate were performed and analysed using a dr/2010 portable data logging spectrophotometer (hach, usa). 2.2 statistical design of experiments in this study, the box behken was applied based on the design expert software version 6.0. determination of the doe aims to reduce the number of experiments and obtain the optimum response (y) according to the interaction of all the factors (xi) were involved. the response (y) was related with three factors can be described by polynomial equation (1): y = β0 + k∑ i=1 βixi + k∑ i=1 βiix 2 i + k∑ i=1 βijxixij + ε (1) the relationship among the three factors mathematically based on the second order as given in equation (2) is: y = β0 + β1x1 + β2x2 + β3x3 + β11x12 + β22x22 +β33x32 + β12x1x2 + β13x1x3–β23x2x3 (2) where,y is the predicted response, βi is the coefficients, βii is coefficients of the quadratic terms, βij is the coefficients of the interactions of factors ε is random error. the response of this study was value of cod (y) while the affecting factors were concentration of pome (x1), ph of solution(x2) and transmembrane pressure (x3). all factors and their levels affects on pome treatment process were selected as concentration varying between 10 to 90 and of solution adjusted between 3.0 to 11.0 using hydrochloric acid and sodium hydroxide, while the transmembrane pressure between 0.5 to 2.5 kpa as summarized in table 1.the total number of experimental runs was 17 based on the box design and given in table 1.the effects of the interaction among all the factors to reduce cod value were evaluated through an analysis of variance (anova) according to experimental results. moreover, it was important to check the adequacy of the model using diagnostic graphs and validity of model by comparing the predicted to experimental results as the main steps (muneer, 2013a,c). table 1. parameters and levels of box behken design independent xi -1 levels factors 0 1 pome concentration, (vol. %) x1 10 50 90 ph x2 3 7 11 tmp, (kpa) x3 0.5 1.5 2.5 3. results and discussion 3.1 model fitting of box behken design the effects of pome concentration, ph of solution and transmembrane pressure on the final value of cod were investigated using the quadratic polynomial model. the mathematical model of pome treatment optimization was estimated based on the experimental results using box behken design with the respective coefficients as given in equation (3): y cod = 78.36563 − 0.49438x1 − 8.46437x2 + 0.40000x3 +0.011198x21 + 0.38547x 2 2 − 1.25000x32 − 0.027594x12 +0.10831x13 + 0.52063x23 (3) © 2019 the authors. page 40 of 46 said et. al. indonesian journal of environmental management and sustainability, 3 (2019) 39-46 the final model creates by the box behken design was involved all the coefficients which shown as a quadratic regression. the theoretical (predicted) values of final cod using the created model were compared to experimental results as listed in table 2. the analysis of variance (anova) results of the box behken model was presented in table 3. the significance degree of the model and all the factors (x1, x2 and x3) are estimated according to the p-value. if this value that less than 0.050 which was considered to be significant, and any other value that is greater than 0.050 was not significant (jafarzadeh, 2011). the higher significant factors of pome concentration (x1), the ph (x2) and then transmembrane pressure (x3) well as the interaction between the pome concentration and the ph (x21) were observed. however, the lack of fit of box behken model with f-value of 0.9193 exhibits to be insignificant relative to the pure error (zhang, 2009). additionally, other important terms are the accuracy and variability of the box behken model, which can be estimated according to the r-squared (r2) value which is between 0 to 1, with a value closer to1 being a better prediction of the response (karacan et al., 2007). the r2 of the box behken model showed a higher value, which was 0.9692. on the other hand, the adj r-squared (radj) coefficient was also found to be 0.9297, which was agreed to the r2 value. however, adequate precision term of box behken was used for evaluated the predicted range of responses relative to the associated error. for this process, the value greater than 4 as 18.019 was found which attributed to support the fitness of the final model (korbahti and rauf, 2009).these values shows a good correlation between the all factors of the pome treatment process using the box design. 3.2 adequacy check of the box behken model some plots to investigate the optimization pome treatment process using the box behken design are given in fig.2. the normality term which indicates the relationship between the student zed residuals with normal probability (fig 2 a) showed all points were close to the line. this result confirmed there no obvious problems with the normality of the design based on experiments result of cod. fig.2 b show the plot between the studentized residuals and the predicted cod values which as random scattering of all the points rather than a funnel-shaped pattern was obtained. this results, confirms that the response was an original observation of variance and no problem with the response [20]. the values of the studentized residuals were almost at intervals of between -3.5 to +3.5 as shown in fig.2 c, and the observed response value was not considered for any value beyond these values. this model was a studentized residual value that was lower than ± 3.5, which gives a good fitting of the model to the response surface (rauf et al., 2008). the outlier of the experimental runs pome treatment process clearly gave that all the points in the range of the outlier figure 2. all diagnostic plots of optimization of cod using box behken design, (a) normality, (b) studentized residuals, (c ) outlier t, (d) actual and predicted. as a good distribution for the box behken design model. the actual value of the final cod from the experimental was nearly the same as the value predicted by the model as shown in fig2 d, which due to the higher values of r2 and r2adj terms. 3.3 response surface plotting and optimization of box behken model 3.3.1 effects of concentration and ph solution on cod value the effects of the pome concentration and ph on the cod value of pome treatment were investigated by the rsm based on a box design. the 3-d response surfaces and contour graphs were used to explain the effects of the interaction between two factors as shown in fig. 3 (a,b). it can be observed that the final cod value decreases as the ph was increased from 3.0 to 11.0. this behaviour leads to changing of surface properties of impurities in pome. at higher ph of solution indicates to the charge of the impurities could be equal to the charge on the surface of the membrane. the similarity of these charges gives more hydrophilic nature of the membrane which leads to the impurities not stick to the membrane surface and the trapped to the bulk solution (ahmad et al., 2005). however, at lower ph of solution, the attraction force between the impurities and surface of membrane was increased. this phenomenon guides the impurities to easily attach to membrane surface and then pass through the pores. the impurities was not only included the solid particles but also the organic molecule. the existence of organic molecule can be assumed as the cod value in solution (said et al., 2014). the liner relationship between the final cod and con© 2019 the authors. page 41 of 46 said et. al. indonesian journal of environmental management and sustainability, 3 (2019) 39-46 table 2. experimental runs of box behken design with actual and predicted results of cod response std run no. (x1) (x2) (x3) cod(mg/l) cod(mg/l) (actual) predicted 1 4 10 3 1.5 54.67 53.55 2 12 90 3 1.5 108 109.96 3 10 10 11 1,5 35 33.04 4 3 90 11 1.5 70.67 71.79 5 6 10 7 0.5 32 34.5 6 14 90 7 0.5 74 73.42 7 5 10 7 2.5 36.67 37.25 8 2 50 7 2.5 96 93.5 9 17 50 3 0.5 60.33 58.96 10 9 50 11 0.5 26 25.46 11 16 50 3 2.5 65.67 66.21 12 11 50 11 2.5 39.67 41.04 13 8 50 7 1.5 48.67 43 14 7 50 7 1.5 37.33 43 15 1 50 7 1,5 33.33 43 16 13 50 7 1.5 51.67 43 17 15 50 7 1.5 44 43 table 3. anova results for quadratic model based on the box behken design source sum degree mean f-value p-value of squares of freedom square model 8245.45 9 916.16 24.51 0.0002 x1 4528.19 1 4528.19 121.12 < 0.0001* x2 1720.79 1 1720.79 46.03 0.0003* x3 260.83 1 260.83 6.98 0.0334* x21 1351.73 1 1351.73 36.16 0.0005* x22 160.16 1 160.16 4.28 0.0772 x23 6.58 1 6.58 0.18 0.6874 x12 77.97 1 77.97 2.09 0.1919 x13 75.08 1 75.08 2.01 0.1994 x13 17.35 1 17.35 0.46 0.5176 residual 261.7 7 37.39 lack of fit 27.72 3 9.24 0.16 0.9193** pure error 233.98 4 58.49 total 8507.15 16 *significant at < 0.05% level; ** not significant, r2= 0.9692, r2adj =0.9297, std. dev. = 6.11, mean=53.75, c.v= 11.38, adeq precision=18.019. © 2019 the authors. page 42 of 46 said et. al. indonesian journal of environmental management and sustainability, 3 (2019) 39-46 figure 3. the effect of the concentration and ph on cod value of pome treatment (a) 3-d, (b) contour, (c) interaction centration was observed. by increasing of concentration of pome, the final cod after treatment was increased because higher concentration of pome contained more of impurities and organic molecules. the effects of interaction between the pome concentration and ph to produce on lower value of cod were shown in fig. 3(c). lower value of cod at lower concentration of pome was found which less than 50 mg/l at higher ph of 11.00. however, the interaction between the pome concentration and ph exhibits more affecting at all values which also was confirmed by significant of anova of concentration analysis in table 3 as p-value, 0.0005 < 0.05. 3.3.2 effects of concentration and transmembrane pressure on cod value the effects of concentration of pome and trans membrane pressure on cod value were estimated with different several values as presented in fig.4. slightly affecting of trans membrane pressure on cod with different values especially at lower concentration of pome (10 vol.%) was reported in fig. 4 (a,b). this result is probably due to the lower concentration of pome as indicator to presence of smaller impurities. in addition, the increase in trans membrane pressure makes higher chance of the small particles to pass through the membrane pores (said et al., 2014). at the same time, the cod value was found to increase as the concentration of pome increased due to the presence more amount of impurities in pome solution. to explain that higher of cod value resulting under all values of transmembrane pressure for concentration more than 50 vol.% was found to be because to presence of more impurities. additionally, at higher transmembrane pressure causes to throughout membrane more amount of impurities which attributed to increase the final cod as reported earlier [23]. figure 4. the effect of the concentration and transmembrane pressure on cod value of pome treatment (a) 3-d, (b) contour, (c) interaction the effects of interaction between the pome concentration and transmembrane pressure to produce on lower value of cod were shown in fig. 4(c). at lower pome concentration (10 vol.%), the changing in transmembrane pressure was not affected on cod value due to lower of impurities and organic molecules. the lower cod at lower pome concentration than 50 vol.% under transmembrane pressure of 0.5 kpa was observed. however, the interaction between the pome concentration and transmembrane pressure showed affecting at higher values. 3.3.3 effects of transmembrane pressure and ph on cod value effects of ph and transmembrane pressure on cod value were investigated under several varying values as shown in fig.5. the lower cod values of pome at higher of 11.0 and lower of 0.5 kpa for ph and transmembrane pressure respectively were observed. at lower ph of 3.0 and all transmembrane pressure range, the higher cod values were produced. influence of ph on cod value refers to changing the properties of impurities in pome and membrane surfaces, which at lower ph of solution, the attraction force between the impurities and surface of membrane was increased. this result leads to easily attach of impurities to membrane surface and then pass through the pores which attributed to increasing of cod value. however, the influence of transmembrane pressure also showed the cod value increases as the pressure was increased. this results because under higher transmembrane pressure leads to more impurities pass through the pore membrane compare to under lower pressure which presence of small amount of impurities as reported in previous study (zinatizadeh and mohamed, 2007). the ph of solution shows as the main © 2019 the authors. page 43 of 46 said et. al. indonesian journal of environmental management and sustainability, 3 (2019) 39-46 figure 5. the effect of the transmembrane pressure and ph on cod value of pome treatment (a) 3-d, (b) contour, (c) interaction factor was affected on the performance of pome treatment process which reported for other treatment process earlier (ba-abbad et al., 2013, 2012). 3.4 model validation of pome optimization conditions to check of box behken model validation is very important to produce more stable model for pome treatment process. the main important term use to investigate the validity of the predicted model is desirability function (box et al., 2005). the maximum value of the desirability function (d=1.000 or d≈1.000) was selected to optimize of pome treatment process. to determine factors to produce lower value of cod within the experiment process, the optimization criteria of rsm had five options: none, maximum, minimum, target and within range as shown in table 4. the anova analysis of this model, all factors of pome concentration, ph and transmembrane pressure were significant which each factor contributed affecting within their range option. the minimum value of cod according to the factor as pome concentration =28.30 vol. %, ph =10.75 and transmembrane pressure= 0.69 kpa was to be 24.137 mg/l as shown in fig.6. to investigate the model validity predicted by box behken design, a triplicate of experimental runs under optimum conditions of all factors was achieved. the average cod results was 25.763 mg/l was obtained which in good agreed with the predicted by model. accordingly, the optimization results (comparison between the predicted and experimental results) showed more effective and reliable to apply the box behken design for reduces of cod value which was attributed to a good interaction between the selected factors with their ranges. figure 6. predicted cod, as obtained from the rsm based on box behken design under optimal conditions 4. conclusions in this study, the pome treatment process using reverse osmosis membrane was optimized by appling the response surface method (rsm) based on the box behken design. effects of pome treatment process factors with their interactions were estimated by anova. good coefficients of r2 as 0.9692, r2adj as 0.9297 of the predicted model were obtained. optimum conditions for lower value of response cod were pome concentration =28.30 vol.%, ph = 10.75 and transmembrane pressure= 0.69 kpa. the predicted value of cod under optimal condition was 25.763 mg/l which showed in good agreement with the predicted by model as 24.137 mg/l. this result evidences to support the validity of the model was created by box behken design which also showed as suitable way for optimizing the conditions pome treatment process in future. 5. acknownledgment the authors wish to thank the research centre for sustainable process technology (cespro) , faculty of engineering and built environment, universiti kebangsaan malaysia for support this study under project kk-2013-003. one of the authors (m. m. ba-abbad) is grateful to the hadhramaut university of science &technology, yemen for their financial support for his phd study. also one of authors (muhammad said) is grateful to universiti kebangsaan malaysia (ukm) for supporting through the beasiswa zamalah universiti penyelidikan. references ahmad, a. l., s. ismail, and s. bhatia (2005). membrane treatment for palm oil mill effluent: effect of transmembrane pressure and crossflow velocity. desalination, 179; 245–255 ahmad, c. m. b.-s. i. s., a. l. 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(2009). optimization for decolorization of © 2019 the authors. page 45 of 46 said et. al. indonesian journal of environmental management and sustainability, 3 (2019) 39-46 azo dye green 20 by ultrasound and h2o2 using response surface methodology. journal of hazardous materials, 172(3); 1388–1393 zinatizadeh, a. a. l. and a. r. e. a. mohamed (2007). optimization of pre-treated palm oil mill effluent digestion in an up-flow anaerobic sludge fixed film bioreactor: a comparative study.”. biochemical engineering journal 35(2):, 35(2); 226–237 © 2019 the authors. page 46 of 46 introduction experimental section materials and method statistical design of experiments results and discussion model fitting of box behken design adequacy check of the box behken model response surface plotting and optimization of box behken model effects of concentration and ph solution on cod value effects of concentration and transmembrane pressure on cod value effects of transmembrane pressure and ph on cod value model validation of pome optimization conditions conclusions acknownledgment title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper operational analysis of waste transportation in sukarami district to sukawinatan final disposal ani firda1*, rosmalinda permatasari1, destu lareza1, 1civil engineering study program, faculty of engineering, palembang tridinanti university 2full affiliation of author 2 *corresponding author e-mail: ani.firda@gmail.com abstract increased development, economic growth and population growth in sukarami sub-district also have an impact on changes in the lifestyle of its people, which are becoming more consumptive. this has led to an increase in waste production, which must be managed properly, especially in transportation to the landfill. the purpose of this study was to count the number of dump trucks needed to transport the garbage produced in sukarami district to the final disposal site of the sukawinatan landfill. the data collected in this study were survey data on the generation of waste per capita and the number of residents to calculate the waste generation in sukarami district , as well as survey data on waste transportation, namely the capacity of the garbage truck, the time to load and reduce waste, travel time, travel distance, and route of travel. secondary data collected is a map of sukarami subdistrict, transport vehicle routes, the number of garbage transport equipment in the form of dump trucks, the population, and the number of markets. obtained results that large generationsolid waste generated in sukarami district in 2019 is 427.873 m3 / day, and is predicted to increase to 450.367 m3 / day in 2023. the need for garbage transport vehicles is 29 units of dump trucks. the number of trips needed for dump trucks is 57 trips / day from 2019 2023, 61 trips / day for 2023. keywords waste generation, transportation system , sukarame district received: 5 november 2019, accepted: 23 november 2019 https://doi.org/10.26554/ijems.2019.3.4.116-120 1. introduction the rapid development of urban development in indonesia, followed by an increase in the movement of some rural people to the city has greatly impacted the increase in urban population which is also proportional to the waste that will be generated. until now, the municipal waste management system still relies on the final disposal site (tpa) as a waste management site . s ampah was taken from the location of the source of waste removal or directly to the disposal site (tpa) . this garbage transportation system must be improved because it is related to time and cost efficiency. with the improvement of transport system of garbage , is expected transporting waste to be easy, fast, and relatively low cost . so as to minimize the accumulation of waste that will have a direct impact on public health and the beauty of the city. minimizing distance and travel time is the main solution for waste transportation planning. the garbage transportation route that is made must be effective and efficient so that the optimum transportation route is obtained. palembang city is one of the cities experiencing complex problems in the field of waste management, especially regarding the waste transportation system . one is k ecamatan sukarami which is the nearest district in sukawinatan tpa services. the process of collecting rubbish is carried out using the method of collecting rubbish in the garbage bin in each house and the containers provided at the temporary disposal site (tps). however, this situation is not supported by an effective and efficient transportation system. from this description of the problem, it is very important to carry out further studies on efforts to optimize the process of transporting waste by the number of route waste transport fleets to be effective and efficient. 2. experimental section 2.1 classification method palembang city is located between 2 052’ latitude to 3 05’ latitude and 104037’ to 104052’ east with an average height of 8 meters above sea level. based on pp no. 23 https://doi.org/10.26554/ijems.2019.3.4.116-120 firda et. al. indonesian journal of environmental management and sustainability, 3 (2019) 116-120 figure 1. map of palembang city area in 1988, an area of k ota palembang of 400.61 km 2 , and in the year 2007 is divided into 16 subdistricts and 107 villages . one of the sub-districts in the city of palembang is sukarami sub-district which is the location of a research study. k ecamatan sukarame having an area of 5145.90 hectares with a population of 155 590 inhabitants. (bps, 2018) . sukarami subdistrict is divided into 7 villages, namely sukabangun, sukajaya, sukarame, kebun bunga, talang betutu, sukodadi, and talang jambe. population density in sukarami subdistrict is 32.33 people per ha, where sukajaya urban village has the largest population density compared to other kelurahans in sukarami subdistrict which is 100.33 people per hectare. judging from the composition of the population per sex, the male population in sukarami sub-district is more than the female population, this can be seen from the sex ratio whose value is above 100.00 ie 100.40 with a different male and female population of 330 people. every year a new population arrives, with 1.891 inhabitants consisting of 992 men and 899 women. the number of residents who moved was 1.359 people consisting of 689 men and 670 women (bps, 2018). the sukawinatan final disposal site (tpa) is located in the sukajaya sub-district of sukarami with an area of ± 25 hectares . the sukawinatan landfill has been operating since 1994 , with a distance of ± 10 km to the city center, and is still using the landfill control system and is currently heading for sanitary landfills . while the average amount of garbage entering the landfill is ± 650 tons / day (dlhk, 2019). the process of transporting waste from the tps to the tpa uses a dump truck with a capacity of 6 m3 , while the number of existing garbage transport fleets in sukarami subdistrict is 7 units of dump trucks. waste transportation time is often influenced by several factors, namely transportation routes, vehicle speed, number of attractions, types of roads and activities at the landfill. figure 2. research flow chart 2.2 analysis method data collected are classified into two, namely primary data and secondary data. data primary data is obtained directly through the field survey , conducted by mapping the location of dumps g ’s temporary (tps) and calculate the time and the amount of waste carrier fleet. whereas secondary data in the form of data taken in sukarami district, palembang city environment and cleanliness agency, palembang city statistics agency. the research methodology carried out can be illustrated in figure 2: 3. results and discussion 3.1 waste transportation conditions in sukarami district in this study, the authors determined one sub-district to be used as a research sample, sukarami sub-district with restrictions only on transportation from tps to landfill using 6 m3 dump trucks. the total fleet of garbage trucks and transport routes can be seen in table 1. 3.2 waste transportation time in sukarami district waste transportation time is often influenced by several factors, namely transportation routes, vehicle speed, number of attractions, types of roads and activities at the landfill. the existing condition of the number of waste transportation rations in sukarami sub-district is as much as 2 © 2019 the authors. page 117 of 120 firda et. al. indonesian journal of environmental management and sustainability, 3 (2019) 116-120 table 1. data on the garbage and tps transporting fleet in sukarami district in 2018 no driver type tps transport routes 1 amir hamzah dump tps kantor dlhk bg 8175 mz truck 2 syukuroni dump km.11-jl. kol. burlian/km.7 sebelah kiri bg 8304 mz truck depo transfer kebun bunga 3 agusri dump tps jl. tanjung api-api bg 8021 az truck 4 kasdi rozi dump tps komp. pdk bg 8178 mz truck tps tpu kebun bunga tps perum polantas jl. sukabangun i 5 kailani dump tps talang jambe bg 8120 mz truck tps vip bandara, pdk, grand city 6 indra gandi dump tps jl. adi sucipto bg 8205 mz truck tps jl. alaska tps jl. sukawinatan tps jl. pertandean sukabangun 7 manaf dump tps jl. sepanjang soekarno hatta bg. 4002 lz truck tps grand city table 2. total time of waste transportation research results in sukarami district name capacity distance speed time time amount total vehicle container (±) (v) hold back decrease rit transport time (m3) km (km/hour) (hour) (hour) hour/day a b c d e f = ((a/b)+(c+d))*e bg 8175 mz 6 18 25 1.5 0.3 2 5.04 bg 8304 mz 6 15 25 1.2 0.3 2 4.2 bg 8021 az 6 20 25 1.6 0.3 2 5.4 bg 8178 mz 6 13 25 1 0.3 2 3.62 bg 8120 mz 6 25 25 1.7 0.3 2 6 bg 8205 mz 6 15 25 1.2 0.3 2 4.2 bg 4002 lz 6 23 25 1.5 0.3 2 5.44 rits / day with the first rit working time starting at 06.00 11.00 and the second rit working time starting at 15.00 20.00 while the queuing time for waste reduction in the landfill takes an average of ± 2 ( two hours). 3.3 projection of population in sukarami district in 2018-2023 determination of the projected population in the sukarami district up to 2018 uses the geometric method because the level of development of the population has increased in a number of ways. projected population in sukarami subdistrict from 2013 to 2014 with a population growth rate of 1.03% per year (bps, 2018). so the projected population of sukarami sub-district in 2023 with a growth rate of 1.03% is 163.770 inhabitants. table 3. projection of population in sukarami district from 2018-2023 no years growth total rate (%) population 1 2019 1.03 157.193 2 2020 1.03 158.812 3 2021 1.03 160.447 4 2022 1.03 162.099 5 2023 1.03 163.77 3.4 volume projection of waste in sukarami district in 2023 the projected waste generation will increase every year from 2018 until 2023 is the generation of waste originating from © 2019 the authors. page 118 of 120 firda et. al. indonesian journal of environmental management and sustainability, 3 (2019) 116-120 table 4. projected garbage collection volume for each village in sukarami district per day in 2018 village total waste waste population volume (liters) volume (m3) 1. sukabangun village 19.565 53803.75 53.804 2. sukajaya village 44.114 121313.5 121.314 3. sukarame village 20.265 55728.75 55.729 4. kebun bunga village 28.95 79612.5 79.613 5. talang betutu village 14.866 40881.5 40.882 6. sukodadi village 17.856 49104 49.104 7. talang jambe village 9.974 27428.5 27.429 jumlah 155.59 427872.5 427.873 table 5. projected volume of garbage collection for every village in sukarami district per day in 2023 village total waste waste population volume (liters) volume (m3) 1. sukabangun village 20594 56632.32 56.632 2. sukajaya village 46433 127691.2 127.691 3. sukarame village 21330 58658.52 58.659 4. kebun bunga village 30472 83797.89 83.798 5. talang betutu village 15648 43030.72 43.031 6. sukodadi village 18795 51685.5 51.685 7. talang jambe village 10498 28870.47 28.87 jumlah 163770 450366.6 450.367 settlements, while the generation of waste originating from other sources is projected to be the same throughout the year. the projection of solid waste generation in each village in sukarami sub-district per day in 2018 and 2023 can be seen in tables 4 and 5. 3.5 vehicle needs calculation waste transportation in sukarami district is carried out with two systems namely the hauled container system and the stationary container system (dlhk, 2019). the ideal number of trips per day with the conditions in the present sukawinatan landfill and working time of 10 (ten) hours a day is 2 (two) trips, so that existing waste generation per day in sukarami district that can be transported is as big as: the garbage is transported = trip / day x number of containers / day x container capacity = 2 x 7 x 6 = 84 m3 / day the calculation of the number of trucks needed for a fixed container system / scs (stationary container system) is as follows: 3.5.1 determine the number of trips / day • number of trips / day = embossed truck waste (existing in 2019) = 343,873 m3 / day / 6 m3 = 57.31 trips / day or 57 trips / day • number of trips / day = embossed truck waste (projected year 2023) = 366,367 m3 / day / 6 m3 = 61.06 trips / day or 61 trips / day 3.5.2 determine truck needs the need for trucks to make 57 trips / day (existing in 2019) and 61 trips / day (projected in 2023) can be searched as follows: • determine the operating time if using a dump truck unit operating time = number of trips / day x time of one trip (existing in 2019) = 57 x 5 hours = 285 hours (existing 2019) operating time = number of trips / day x time of one trip (projected year 2023) = 61 x 5 hours = 305 hours (projected in 2023) • determine the number of trucks needed: amount = (operating time / working time a day) x one unit dump truck = (285 hours / 10 hours) x 1 unit = 28.5 ˜ 29 dump truck units (existing 2019) amount = (operating time / working time a day) x one unit dump truck = (305 hours / 10 hours) x 1 unit = 30.5 ˜ 31 dump trucks (projection in 2023) the calculation results show that additional trucks are needed and the number of trips / day is needed. 4. conclusions the garbage transportation system in sukarami district, palembang city is carried out in 2 (two) ways, namely a direct individual system and the placement of garbage containers in a temporary disposal site (tps). the commu© 2019 the authors. page 119 of 120 firda et. al. indonesian journal of environmental management and sustainability, 3 (2019) 116-120 nal system is directly carried out using motorized carts and dump trucks while transporting garbage containers with arm roll trucks. the number of trips / rubbish transportation trashes currently available in sukarami district, palembang city is 2 (two) trips per day, where the first trip operational hours are 06.00-11.00 hours and continued for the second trip, which is 15.00-20.00. where for the current number of dump trucks as many as 7 (seven) units of capacity of 6 m3 with an average transport distance of ± 20 km per trip. the need for dump truck garbage transport vehicles needed in surakarami sub-district, palembang city in 2019 is 29 units of 6 m3 dump trucks and the projected need for 2023 is 31 units of 6 m3 dump trucks, prediction of waste generation in sukarami district in the year 2019 based on population growth of 1.03% per year is settlement waste of 427,873 m3 / day while the projected solid waste generation in 2023 is 450,367 m3 / day. 5. acknowdlegment acknowedgement for palembang city environment and cleanliness agency references bps (2015). badan pusat statistik: kecamatan sukarami dalam angka 2015. badan pusat statistik kota palembang. palembang bps (2018). badan pusat statistik: kecamatan sukarami dalam angka 2015. badan pusat statistik kota palembang. palembang dlhk (2019). dinas lingkungan hidup dan kebersihan kota palembang: jumlah truk angkutan sampah pada dinas pertamanan dan kebersihan kota palembang kondisi bulan desember tahun 2018. dinas lingkungan hidup dan kebersihan kota palembang. palembang pemerintahindonesia (1988). pp nomor 23 tahun 1988 tentang perubahan batas wilayah kabupaten daerah tingkat ii palembang, dan kabupaten daerah tingkat ii musi banyuasin dan kabupaten daerah tingkat ii ogan komering ilir. lembaran ri tahun 1988 no. 44. jakarta : sekretariat negara. perda (2012). peraturan daerah kota palembang no. 15 tahun 2012 tentang rencana tata ruang dan wilayah (rtrw) kota palembang 2012-2032 prie, g. (2015). studi sumber timbulan sampah di pasar daya makassar. universitas hasanudin makassar. makassar prihandarini (2011). analisis sistem pengangkutan sampah kota makassar dengan metode penyelesaian vehicle routing problem (vrp) (studi kasus: kecamatan mamajang). universitas hasanudin makassar. makassar © 2019 the authors. page 120 of 120 introduction experimental section classification method analysis method results and discussion waste transportation conditions in sukarami district waste transportation time in sukarami district projection of population in sukarami district in 2018-2023 volume projection of waste in sukarami district in 2023 vehicle needs calculation determine the number of trips / day determine truck needs conclusions acknowdlegment title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper assessment of farmer’s tree preferences and their seasonal frost management practices in frost-affected highlands of eastern ethiopia goremsu getachew1*, daba bogale2, abera tesfaye1 1ethiopian forestry development, central ethiopia research center, addis ababa, 33042, ethiopia 2ethiopian forestry development, dire dawa center, dire dawa, 1708, ethiopia *corresponding author e-mail: goremsugetachew@gmail.com abstract deforestation, land degradation, and low survival of planted seedlings are serious problems in highland ethiopia. to address these problems, different land management practices such as afforestation and conservation program have been implemented; however, the success to date limited due to environmental stress and insufficient post-planting care. therefore, the objective of this study was to investigate farmer’s tree needs and their traditional knowledge of seasonal frost management practices in selected frost-affected highlands of eastern, ethiopia. a total of 111 households were randomly selected for interviews on farmer’s tree species preference, frost management practices, and the causes of seedling mortality in the study area. furthermore, key informant interviews and focus group discussions were used to collect the data. descriptive statistics were used to analyze the data. the results confirm that season frost (55.6%) followed by free grazing (22.2%), inappropriate species site match (11.1%), and inappropriate planting time (5.6%) were major causes of seedling mortality in the study area. organic mulch, plant cover, smoking, watering, and manuring were seasonal frost management practices applied by farmer’s to enhance seedlings’ survival in the study areas. however, this indigenous knowledge should be encouraged by the government through improved research, and extension services, to enhance seedlings’ survival in the study areas as well as to introduce it in different frost-prone highlands of ethiopia. moreover, species such as eucalyptus globulus’ labill, cupressus lusitanica mill., juniperus procera hochst. ex endl., hagenia abyssinica a (bruce) j.f.gmel, and podocarpus falcatus (thunb.) mirb. (syn. p. gracilior pilg.), were suggested as frost-tolerant species in the study area. therefore, it is recommended that planting these tree species through research and campaign is essential to reduce land degradation in the frost-affected highlands area of the country, particularly in the study area. keywords eastern highlands, frost hardiness, indigenous knowledge, tree survival received: 15 december 2022, accepted: 10 march 2023 https://doi.org/10.26554/ijems.2023.7.2.38-46 1. introduction the ethiopian highlands are the largest mountain complex in africa and are rich in a diverse variety of flora and fauna species and nowadays, the percentage of forest cover is less than 4% (hurni et al., 2010; meshesha et al., 2014; nyssen et al., 2015). rapid deforestation and degradation are severely threatening the forest resources in the highland parts of ethiopia (lemenih and teketay, 2004). agricultural expansion, population pressure, free grazing, and overexploitation of forests for fuel wood, fodder, and construction materials are the main causes of deforestation and land degradation in highland parts of ethiopia (tefera et al., 2014; tigabu et al., 2014). these deforestation and land degradation had an economic and ecological impact at both local and national levels. for instance, biodiversity loss is accelerated; ecosystem services such as carbon sequestration are also threatened, and reduced capacity of the forest to contribute to products and food security (taddese, 2001; gebre et al., 2019). drought, invasive species, and climate change are the new threats to forest resources in ethiopia (bishaw, 2001). environmental factor together with deforestation and land degradation has resulted in a shortage of wood products such as fodder, timber, and fruits. furthermore, environmental stress (frost, low humidity, and drought) together with insufficient post-planting care, poor-quality nursery stock, and limiting site conditions are the main causes of the death of transplanted tree seedlings in ethiopia (lemenih and teketay, 2004; eshetie et al., 2020). for example, frost is a significant climatic phenomenon that influences the https://doi.org/10.26554/ijems.2023.7.2.38-46 getachew et. al. indonesian journal of environmental management and sustainability, 7 (2023) 38-46 distribution of plant species, particularly in highland areas (rorato et al., 2018). it hinders tree growth and reduces the productivity of forests in the long run. frost also causes the formation of ice crystals in the extracellular spaces. as a result of the difference in water potential, water in the cell protoplasm is directed to the extracellular spaces, causing damage because the cell loses water, resulting in dehydration (rorato et al., 2018). however, assessment of species selection and local management practices of frost are crucial to enhance seedling’s survival in frost-affected areas. to address environmental challenges, efforts have been made to launch afforestation and conservation programs; however, success has been limited thus far (eshetu et al., 2014). the lack of information on the performance of tree species after planting and their responses to environmental conditions has made listing potential species for restoring frost-affected areas a difficult task. therefore, careful species selection is required to avoid frost-sensitive species, especially for restoration and afforestation programs in frost-affected areas (rorato et al., 2018). yet, detailed analyses of the forest resources crises associated with the destruction and practical solutions on how to effectively reverse the course of destruction in the country are generally limited. hence, to make plantation and restoration work effective, critical assessments of possible limitations and improving seedling establishment and management techniques in degraded frost-affected highlands would be vitally essential. with this regard, tree species selection for the restoration and management of environmental factors are essential as environmental stress may affect seedling survival in the highland area differently. there have been limited studies concerning farmer’s tree preferences and traditional knowledge of seasonal frost management practices in frost-affected degraded highlands of eastern ethiopia. thus, an investigation of farmer’s tree needs and traditional knowledge of seasonal frost management practices was conducted to answer the following questions: (1) how and why do local farmer’s manage the frost in the study area? (2) which tree species were suggested as frost tolerance in the study area? to address these research questions, the following specific objectives were developed. therefore, the objectives of this study were :(1) to describe e farmer tree species preferences, main niches, and traditional knowledge of seasonal frost management practices in the study area; and (2) to identify frost tolerant tree species in the study area. thus, the present study provides information about appropriate species selection for frost-affected areas, and environments and resolves land degradation problems through afforestation/reforestation and area ex-closure strategies by improving seedling establishment and management practices in frost-affected highlands. the outcome of this research serves as input for scientific studies, researchers, governmental and non-governmental organizations, policy and decisionmakers, and forestry projects in the area and at the national level. 2. materials and methods 2.1 description of the study area the study was conducted in the haramaya and girawa districts of east hararghe zone, oromia regional state, ethiopia. haramaya district is located around 9° 0’-9° 5’ n and 42° 0’-42° 24’ e and between 1400 and 2340 m above sea level while girawa district is found around 8° 42’-9° 24’ n and 41° 24’-42° 24’ e and between 1215 and 3405 m above sea level. the mean annual rainfall ranges from 769 to 1150 mm in the haramaya (marru et al., 2013) and 550 to 1100 mm in the girawa district (beyan ahmed and geta, 2013). the average mean annual temperature is 18 ◦c in the haramaya (marru et al., 2013) and 20 ◦c in the girawa district (beyan ahmed and geta, 2013). both haramaya and girawa district has three agroecological zones namely highland, midland, and lowland. these agroecological zones vary by altitude and rainfall distribution. the two study kebeles are located in the highland agroecological zone. the physiographic condition of the study areas are plateaus, rugged dissected mountains, deep valleys, gorges, and plains (beyan ahmed and geta, 2013; marru et al., 2013). cultivated lands, pasture lands, and forest lands are the land use type found in the study areas (beyan ahmed and geta, 2013; marru et al., 2013). the dominant soil types in the study areas are nitosol, cambisols, and vertisols (beyan ahmed and geta, 2013; marru et al., 2013). the total population is 271,018 in haramaya and 240,173 in girawa district (authority, 2015). rainfed agriculture with a mixed farming system (crop production and livestock rearing) are the primary livelihood source of the inhabitants in both study areas (beyan ahmed and geta, 2013; marru et al., 2013). maize (zea mays), common bean (phaseolus vulgaris), pulse (haricot bean), oilseed, vegetables, and fruits are the most dominant crops in both districts (ahmed et al., 2017). moreover, khat (catha edulis forsk) and buna (coffea arabica l.) khat (catha edulis) are the dominant cash crop grown in both districts. 2.2 sampling techniques in the present study, a multi-stage sampling procedure was used to conduct a household survey. first, preliminary information was collected at the district level through discussions with agricultural experts and local elders who know about degraded lands and frost-prone areas. the discussions were focused on degraded areas, frost occurrence, and frost-prone areas. then, a reconnaissance survey was conducted to characterize degraded areas and frost-prone highlands. secondly, two districts (haramaya and girawa districts) where seasonal frost is a major threat were selected purposively. thirdly, two kebeles (tinike from haramaya and birbrsa from girawa district) were selected purposively with frostprone areas. the reasons for having the two selected kebeles were due to the presence of degraded areas, frost occurrence, and frost-prone areas. moreover, the reason to have two © 2023 the authors. page 39 of 46 getachew et. al. indonesian journal of environmental management and sustainability, 7 (2023) 38-46 figure 1. map of the study area kebeles samples was for replication purposes. the lists of households living in the kebeles were obtained from kebele offices and crossed checked with key informants for their inclusiveness. we identified a total of 1840 households (640 from tinike kebele and 1200 from birbrsa kebele). finally, a total of 111 households, 39 from tinike and 72 birbrsa kebeles, were randomly selected for interview. the proportional sample size formula, which was adapted from the (kothari, 2004) method, was used to determine the needed number of household respondents from the two kebeles. n = z2pqn e2(n − 1) + z2pq where: p = probability of success = 0.5 and q = 1-p (1-0.5) = 0.5 n = total number of households in selected kebeles (1840) z = confidence level at 95% which is 1.96 from z-table e= the margin of error considered as 9% for this study which is 0.09 n = 1.962(0.5)(0.5)(1840) 0.092(1839) + 1.962(0.5)(0.5) = 111 the number of households for each kebele was calculated as shown below: n = n ∗ n1 n where, n = sample size in respective kebele, n1 = total number of the households included in the study (111), n = total number of households in both kebeles (1840). n(tinike kebele) = 640 ∗ 111 1840 = 39 n(birbrsa kebele) = 1200 ∗ 111 1840 = 72 2.3 method of data collection to achieve the study objectives both quantitative and qualitative data were used. in this study, both primary and secondary data sources were used. the secondary data were collected from published and unpublished documents to get an overview of the study sites and frost. the primary data were gathered through household surveys, key informant interviews, and focus group discussions. closed and open questionnaires were developed and semistructured and face-to-face interviews were conducted to collect qualitative and quantitative data from respondents. the household questionnaires were prepared in english and translated into afan oromo, the study area language. enumerators who were experts and knowledgeable about the area were involved in data collection. before interviewing household respondents, the objectives of the study were explained to enumerators, and they were trained in data collection and interview methods. for qualitative data, both key informant interviews and focus group discussions were conducted. in this study, key © 2023 the authors. page 40 of 46 getachew et. al. indonesian journal of environmental management and sustainability, 7 (2023) 38-46 informants are defined as persons who are knowledgeable about frost, frost occurrences, and frost management practices and who have lived for a long time in the respective kebele. the selection of key informants was done by using the snowball sampling method (bernard, 2017). twelve key informants (six per kebele) were interviewed for the entire study. the purpose of selecting key informants was to identify the local name of tree species and to cross-check the number of households living in the kebeles. the following points were addressed during key informant interviews: farmer’s tree species preferences, frost management practices, and major causes of seedling mortality in the study areas. in the focus group discussion, model farmer’s, youths, and women households were selected from each kebele. the focus group discussions were conducted separately with men and women and with different wealth ranks. the purposes of the discussions were to verify farmer tree needs and traditional frost management practices. the information generated here was used to validate the information obtained from household respondents. 2.4 data analysis and presentation the data were analyzed by using both quantitative and qualitative methods. before data analysis, data encoding and data management were conducted. then, the quantitative data were analyzed by using descriptive statistics (frequency, percentage, and means) with the spss version 25 package software program. on the other hand, qualitative data interpretation was done through the description and narration in words. 3. results and discussion 3.1 households and socio-economic characteristics in this study, the socio-economic features of the sampled households were assessed and presented (table 1). about 79.3% of the respondents were men. marital status also showed that the majority of sampled respondents were married (91.3%), and the remaining were divorced. the average age of the sample households was 39.5 years. the majority (39.5%) of them had ages between 30 and 45 years old. concerning, educational status, the majority of sample respondents (57.6%) were illiterate (table 1). the mean land holding size of the sampled households at the study sites were 0.58 ha and it was a major fixed asset for farmer’s in the study area. farmer’s in the study area pursued farming in which livestock production was a component. cattle, goats, donkeys, mules, and poultry were important species of livestock kept by farmer’s in the study area. the average total livestock holding of the sampled respondents was 5.8 tropical livestock units. farming was the primary occupation for all of the households, which represents about 92.4% and 7.4% of the households were involved in other income such as petty trading, charcoal selling, and labor work. 3.2 the source of seedlings, planting niches, and species preference for planting about 66% of respondents stated that they got seedlings from government nurseries, 21% of them produced seedlings in their nurseries by broadcasting seed on prepared plantation sites, while 12% and 1% of the respondents get seedlings from other private nurseries and ngo-owned nurseries, respectively (figure 2). this was supported by the finding of dedefo et al. (2017) who reported that government nurseries followed by individual groups, non-governmental organizations, and projects provide seedlings for farmer’s, afforestation, and community tree planting programs. moreover, farmer’s can also participate in the production of tree seedlings individually or collectively to access markets for their consumption (gregorio et al., 2015; dedefo et al., 2017). figure 2. the main source of seedlings for planting in the study area in this study, households retained tree species in different land use types for multiple products and services. therefore, in the present study, the most preferred niches for planting tree species were boundary planting followed by homegarden and scattered trees in crop filed (table 2). farmer’s tree planting was limited to boundary and homegarden could be to prevent disturbance from animals and for better management of the tree species. boundary planting and homegarden were preferred because browsing and fire were easier to control, and manure and refuse could be applied more easily than in a distant field. women, in particular, stated that they prefer planting trees close to their homes so that they do not have to leave their homes for long periods in search of fuel wood medicine and animal fodder. furthermore, planting close to home reduces the risk of others secretly collecting fruits from their trees. planting along borders is also done to mark the boundaries and deter stray animals. the majority of tree species are retained in boundary planting and homegarden to meet the immediate needs of the household, such as food, medicines, income, handcrafting materials, and ecological needs. this conforms to the results reported by fikir et al. (2018), that farmer’s only planted trees in their backyards and boundary © 2023 the authors. page 41 of 46 getachew et. al. indonesian journal of environmental management and sustainability, 7 (2023) 38-46 table 1. socio-economic characteristics of the sampled household heads (n=111) interviewed in the study area variables categories number (%) of respondents mean sex male 88(79.3) female 23 (20.7) marital status married 101(91.3) divorced 10(8.7) age (years) 39.5 educational status illiterate 64 (57.6) literate 47 (42.4) size of land holding (ha) 0.58 family size 5.7 total livestock in tlu 5.8 planting due to the homeowner feeling a strong sense of ownership and trees directly managed by household members. moreover, such a tendency to maintain multipurpose species limited to the homestead and boundary planting may be for the sake of easing management practices, to protect the farm from theft, and livestock grazing (negash, 2007; fikir et al., 2018). in addition, farmer’s maintained scattered tree species on their crop fields for their wood products and soil fertility improvement. furthermore, the respondent stated that they match planting niches with planting objectives. for instance, a species that will grow in farmlands loses its leaves before it starts to rain and easily decomposes to improve the fertility of the soil. table 2. the main niche where the farmer’s grow tree species in the study area planting niches percent home garden 20.9% scattered trees in the crop field 17.9% boundary planting 61.9% from the total respondents, about 73% of the respondents mentioned that they planted tree species and managed for a different purpose in their farmland while the remaining 27% of the respondents did not plant tree species on their farms. the major reasons farmer’s did not grow the tree on their farms are due to the shortage of land (52%) and lack of planting materials especially fruit trees (48%). likewise, previous studies have reported various constraints that could affect the integration of tree species in farmland including land shortage, lack of seedlings for planting, poor survival of seedlings, and lack of sufficient material (dedefo et al., 2017; fikir et al., 2018). according to the respondent, eucalyptus globulus (94%), cupressus lustinica (52%), olea africana mill. (36%), jufigure 3. most preferred tree species for planting on farmer’s fields in the study area niperus procera (23.8%), cordia africana lam. (21%), and podocarpus falactus (19%) were tree species planted on their farms for different products and services. eucalyptus globulus is exotic species that was retained in farmlands for its pole for construction, timber, source of cash, and fuelwood, as it is fuelwood demand is high in the highland area. moreover, the species are highly preferred by farmer’s in the study area due to their easy adaptability, propagation, and management regimes of eucalyptus globulus. a previous study elsewhere reported that eucalyptus globulus was the most performed tree species in the highland of ethiopia (mekonnen et al., 2006; tesfaye et al., 2015; fikir et al., 2018). furthermore, eucalyptus globulus species support the livelihood of local peoples through the sale of stands, fuelwood, and building materials (kebede, 2022). 3.3 farmer’s species selection criteria and preferences of tree products/ services in the study area, farming households have long relied on tree species for different products and services. about 50.5% © 2023 the authors. page 42 of 46 getachew et. al. indonesian journal of environmental management and sustainability, 7 (2023) 38-46 of the respondent’s plant tree species for the production of fuel wood and 24.9% of the respondents’ plant trees for the production of poles for construction (table 3). they also retained tree species for diverse purposes such as fruit, fodder production, soil fertility improvement, erosion control, shade, and medicinal value. the majority of farmer’s, used tree species for fuelwood may be due to the fuelwood shortage is a critical problem in highland areas. farmer’s normally retained tree species in farmland for multiple useful and valuable purposes to optimize the capture and use of environmental resources (negash, 2007). this is dependent on the tangible that they render to the household such as food, cash income, medicine, fodder, bee forage, shades, live fences, improve soil fertility through mulching, animal feed as fodder, shade reduction over integrated crops, fuelwood, timber and construction wood (mohammed and asfaw, 2015; mamo and asfaw, 2017). the other reasons farmer’s integrate tree species in farmlands are also to regulate leaching and improve crop yield, productivity, and sustainability of the land (negash, 2007). table 3. tree services and products most preferred by respondents in the study area tree products/service percent fuelwood 50.5% fodder 6.8% soil fertility and erosion control 3.5% fruits 8% medicine 1.3% shade 5% pole for construction 24.9% according to the survey result, fast-growing (64.2%,) followed by multiple uses (23.9%), drought resistance (7.5%), and ease of establishment (11%) were the major criteria for selection of tree species to plant in their farmlands (table 4). fast growing was the most preferred attribute of tree species in the study area. similarly, fast-growing and high biomass-producing tree species were preferred in highland areas (mekonnen et al., 2006). this finding was also supported by negash et al. (2012) reported that farmer’s prefer species that give multiple products and services. furthermore, fast-growing tree species are being increasingly integrated with traditional land-use types, mainly for poles for construction and timber. furthermore, farmer’s employ some characteristics, including fast growth, utility, compatibility, multipurpose use value, and drought resistance to incorporate tree species on farms (mohammed and asfaw, 2015). 3.4 causes of seedlings mortality about 97% of the respondents had information on treeplanting activities and seedling survival in the study area. table 4. attributes of trees most valued by respondents in the study area attributes percent rank drought resistance 7.5% 3rd fast growing 64.2% 1st ease of establishment 4.5% 4th multiple uses 23.9% 2nd the respondents noted that the major causes of seedling mortality were frost (55.6%), free grazing (22.2%), inappropriate species site match (11.11%), inappropriate planting time (5.6%), inappropriate planting material (3.3%), and drought (2.2%) (figure 4). previous studies elsewhere supported that insufficient management care, species site match, and limited site condition contributed to the death of transplanted trees before they can make a meaningful economic and environmental contribution to the communities (eshetie et al., 2020). on other hand, many factors influence the survival of seedlings and their importance varies according to the species and agroecological condition (reubens et al., 2009). for instance, insufficient soil moisture during the early growth stage is one of the most important causes of high seedling mortality; hence watering during this period can improve seedling survival (jegora et al., 2019) and animal grazing and termite were the two major biotic factors for survival of transplanted tree species (eshetie et al., 2020). furthermore, weeds can pose a threat to the planted seedlings, especially in the first year, due to competition for water, nutrients, and light and weeding can have a positive effect on seedling survival (eshetie et al., 2020). 3.5 seasonal frost occurrence and management practices the result indicated that frost was occurring once a year (monomodal). therefore, the majority of respondents, 84.5% stated that seasonal frost occurs once a year (between septemberjanuary). this line with the finding of charrier et al. (2015) who reported that with the current climate condition, the risk of frost damage is greatest in the autumn or spring. to enhance seedling survival and mitigate frost farmer’s applied frost management techniques. therefore, about 64% of respondents pointed out that they used local frost management practices while 36% of the respondents didn’t apply any management practices. the management practices applied for frost protection were organic mulch (39%), plant cover (32%), smoking (23.7%), watering, and manuring (5%). the result is in line with the finding of amin et al. (2018) reported organic mulch and plant cover were the two important management practices for enhancing the survival of transplanted seedlings. respondents stated that there is no prevention method to protect seedlings and crops from frost damage. it is an © 2023 the authors. page 43 of 46 getachew et. al. indonesian journal of environmental management and sustainability, 7 (2023) 38-46 figure 4. causes of seedling mortality in the study areas figure 5. farmer’s frost management practices in the study area emergency or natural disaster that partially or completely damages the planted seedlings. therefore, they apply management practices to enhance the survival of seedlings and crops, but not for the total prevention of frost. damage from abiotic stresses such as frost may hinder tree growth and affect the productivity of forest products (figure 6). therefore, assessing and documenting traditional knowledge of frost risk is critical for forestry and agriculture. concerning the stage when seedlings are more prone to frost damage, 54.3% of the respondents reported that seedlings at the first 6 months of their growth stage were prone to frost damage. this was supported by the finding of eshetie et al. (2020) who reported that the seedlings were dead in the first seven months after planting between july to january and also a similar finding was reported that frost damage often occurs on newly planted seedlings (man et al., 2009). 3.6 tree species suggested as frost-tolerant species species respond differently to frost, regardless of the size of the container in which the seedling is produced or the ecologfigure 6. the pictures show the effect of seasonal frost on catha adulis (a) and coffea arabica (b) species in the study areas ical group. the result shows that species such as eucalyptus globulus(45.3%) followed by cupressus lusitanica (23.3%), juniperus procera (18.9%), haginia abyssinica (10%), and podocarpus flactus (2.5%) were suggested as frost-tolerant species in the study area (figures 5 and 7). a previous study elsewhere reported that eucalyptus globulus and cupressus lusitanica were the most performed tree species in the highland of central ethiopia (mekonnen et al., 2006). therefore, planting these species play an important role in the rehabilitation and restoration of degraded land in highland areas. © 2023 the authors. page 44 of 46 getachew et. al. indonesian journal of environmental management and sustainability, 7 (2023) 38-46 table 5. the main stages of the seedlings susceptible to frost (n = 111) in the study area the main stage of planted seedlings susceptible to frost frequency percent first six months after planting 60 54.3% the first year after planting 35 31.5% first two years after planting 12 10.9% first three years after planting 4 3.3% figure 7. tree species suggested by respondents as frost tolerant in the study area 4. conclusions the present study has provided valuable information on the assessment of farmer’s tree needs and their traditional knowledge of seasonal frost management in the study area. the result of this study confirms that boundary planting and homegarden were the most preferred planting niches in the study area. frost is an emergency or natural disaster that partially or completely damages the planted seedling in the study area. therefore, organic mulch and plant cover were the two most important management practices for enhancing the survival of transplanted seedlings in the study area. however, these management practices should be encouraged by the government through improved research, and extension services, to enhance seedlings’ survival and successful establishment of tree species in the study areas. species eucalyptus globulus, cupressus lusitanica, and juniperus procera were suggested as frost-tolerant species in the study area. therefore, we recommended that planting these tree species through research and campaign is essential to essential to reduce land degradation in the frost-affected highlands area of the country, particularly in the study area. 5. acknowledgement the first author acknowledges the ethiopian environment and forest research institute for their financial support. we are grateful to all staff of the haramaya and girawa district agricultural and rural development office for their technical support and field guidance while collecting data. references ahmed, m. h., k. m. geleta, a. tazeze, h. m. mesfin, and e. a. tilahun (2017). cropping systems diversification, improved seed, manure and inorganic fertilizer adoption by maize producers of eastern ethiopia. journal of economic structures, 6(1); 1–16 amin, m., a. jaleta, and h. bersisa (2018). evaluation of mulching practice on the survival and subsequent early growth performances of the transplanted coffee seedlings. universal journal of agricultural research, 6(4); 119–126 authority, e. r. 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(2001). land degradation: a challenge to ethiopia. environmental management, 27(6); 815 tefera, b., m. l. ruelle, z. asfaw, and b. abraha tsegay (2014). woody plant diversity in an afromontane agricultural landscape (debark district, northern ethiopia). forests, trees and livelihoods, 23(4); 261–279 tesfaye, m. a., a. bravo-oviedo, f. bravo, b. kidane, k. bekele, and d. sertse (2015). selection of tree species and soil management for simultaneous fuelwood production and soil rehabilitation in the ethiopian central highlands. land degradation & development, 26(7); 665– 679 tigabu, m., l. mulugeta, m. negash, d. teketay (2014). rehabilitation of degraded forest and woodland ecosystems in ethiopia for sustenance of livelihoods and ecosystem services. iufro world series, 32; 299–313 © 2023 the authors. page 46 of 46 introduction materials and methods description of the study area sampling techniques method of data collection data analysis and presentation results and discussion households and socio-economic characteristics the source of seedlings, planting niches, and species preference for planting farmer's species selection criteria and preferences of tree products/ services causes of seedlings mortality seasonal frost occurrence and management practices tree species suggested as frost-tolerant species conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper the analysis of energy efficiency and emission rate of a cookware coated with enamel material pramadhony1*, martin luther king2, muhammad lazim2, sukarmansah2, helmi ibrahim3 1student of doctoral program, department of engineering science, sriwijaya university, palembang 30139, indonesia 2mechanical engineering department, university of tridinanti palembang, palembang, 30129, indonesia 3student of mechanical engineering department, university of tridinanti palembang, palembang, 30129, indonesia *corresponding author e-mail: pramadhony@yahoo.com abstract metal cookware has been used many people for its better thermal conductivity. however this material also has some weaknesses for its reaction with acidic food which will contaminate the food. metal-base material coated with enamel is one of the solutions. the hard and non-reactive surface has cause this material has been widely used for processing food. lower thermal conductivity is one of the problems of enamel cookware. the experimental analysis has been conducted to investigate energy efficiency, emission rate and thermal conductivity. the efficiency is calculated by comparing the useful energy (work) with the input energy. the emission rate is calculated by multiply energy consumption with emission factor. meanwhile the thermal conductivity is calculated by using simply conduction heat transfer equation. based on the analysis, enamel cookware has much lower thermal conductivity than aluminum cookware. however this physical property does not much affects the efficiency. the most dominant factors which should considered are type of fuel and technology of stove which consume higher energy inefficiently and emits much higher hazardous gas. keywords enamel cookware, energy efficiency, emission rate received: 5 november 2019, accepted: 23 november 2019 https://doi.org/10.26554/ijems.2019.3.4.128-132 1. introduction commonly metal based materials are used as main material for cookware product because they have good heat conductivity which is good for better energy efficiency and emission reduction. however these materials have some weaknesses. reaction with acidic food materials and sometime stick with food are the main problems of metal materials. therefore the development of material technology is needed in order to solve the problems. the emerging of non-stick inner coating ptfe in cookware seems gives a solution. but this material is still to be suspected as a source of toxic gas in very high temperature (sajid et al., 2014). another solution is the application of enamel material which can be used to coat metal-base cookware material. cast iron coated with enamel can increase the resistance of cookware against an oxidation (mart́ınez-gomez et al., 2016). therefore, for the safety reason nowadays many metal packaging is coated with enamel (oldring and nehring, 2007). enamel is a non-reactive material which makes this material is safe for storing many kind of food. moreover it has a very hard surface. this property gives some advantages for high durability and the ease for cleaning after the usage. in other side this material also has a significant weakness when applied as a cookware material. the heat conductivity of enamel is far lower than the heat conductivity of a common metal. the addition micro particle such as sio2 or tio2 in enamel layer apparently doesn’t improve the heat conductivity property (ganesan et al., 2013). considering these enamel’s properties, it is necessary to investigate the performance and efficiency of this material when applied on a cookware. since the lower efficiency will cause the increasing of energy consumption, co2 and some hazardous gasses which emitted by burning process. 2. experimental section 2.1 materials the investigation is conducted with two different materials of cookware. the first analysis will investigate the performance of an enamel-coated cookware. and the second analysis investigates an analyze aluminum cookware which is commonly used in household. https://doi.org/10.26554/ijems.2019.3.4.128-132 pramadhony et. al. indonesian journal of environmental management and sustainability, 3 (2019) 128-132 2.2 methods the investigation is begun by measuring the dimension of cook wares. the dimension measurement is conducted with some tools such as: • ruler for measuring diameter. • vanier caliper for measuring depth of cookware. • micrometer screw gauge measuring the thickness. the profile dimension of cookware is estimated by measuring the height and radius of water which is filled in cookware. water is filled in cookware with various volumes. the result of the measurement is shown in table 1. this profile is needed to estimates the contact area between water and inside wall of cookware. dimension and the height equation of cookware are shown in figure 1. in addition volume and contact area of cookware can be estimated by using equation (1) and (2). q = −ka dt dx (1) ein = mfhvf (2) table 1. dimension and contact area of cookware in some various volumes volume dimension (mm) contact (ml) radius height area (cm2) 0 0 0 0 50 55 9.05 100.61 100 67.5 13.1 145.41 200 79 18.2 203.19 300 88.5 22 247.27 400 96 26.65 302.42 500 100 29.75 339.91 600 104.5 32.9 378.6 700 108 35.5 410.98 800 111 37.8 439.95 900 113 40 467.96 1000 114.5 42.2 496.24 figure 1. graphic surface profile of cookware v ol = 2.π ∫ r 0 hrdr (3) area = 2.π ∫ r 0 rds (4) where: ds = √ 1 + ( dh dr )2dr h = -1.4522e-06r3 + 3.3160e-03r2 1.8490e-02r having obtained the dimensions, the research s continued by setting the mass of water (500, 600, 700, 800 and 1000 gram). then each mass of water is heated from 31 °c to 100 °c and at the same time the authors are also counting the time needed. during heating the water, the temperatures of flame, outer wall and inner wall of cookware are measured with thermocouple. each temperature is measured three times to obtain the average temperature. in this research, liquid petroleum gas (lpg) is used as source of energy. mass of lpg is measured in each heating process in order to calculate energy released during the combustion process. 3. results and discussion the result of temperature and time measurements during heating water with enamel and aluminum cookware are shown in table 2 and table 3 respectively. water with various masses are heated from 31 °c to 100 °c. during heating process, some parameters are measured such as temperature (flame, outer wall and inner wall), fuel consumption and heating time. then these data’s are processed to calculate the amount of heat transfer, energy consumption, emission rate and efficiency. 3.1 energy consumption the analysis is begun by calculating energy consumption for each material of cookware. heat energy input is taken from the lpg burning process. the fuel is used on stove to heat up water from 31 °c to 100 °c. mass of lpg consumption is measured and then multiplied with its caloric value. in this calculation, lpg is assumed has caloric value of 11.254,61 kcal/kg or 47.089 mj/kg (esdm, 2013). the calculation result of energy consumption is shown in table 4. 3.2 energy adsorption thermal energy is adsorbed by water and causes the increasing of water temperature. each kg of water needs to adsorb 1 kcal or 4.184 kj of energy to increase its temperature by 1 °c at constant pressure. the amount of energy adsorption is depending on heat transfer between heat source and heated media. the smaller difference between input energy and adsorbed energy means it has better efficiency. the amount of energy adsorbed by water is shown in table 5. © 2019 the authors. page 129 of 132 pramadhony et. al. indonesian journal of environmental management and sustainability, 3 (2019) 128-132 table 2. experimental result of boiling water with enamel cookware mwater mlpg temperature (°c) time (gram) (gram) flame outer cookware inner cookware (s) 500 4.53 601 230 225 160 600 5.43 603 233 227 191 700 6.3 602 234 228 218.7 800 6.7 603 234 229 233.3 1000 8.63 616 239 233 260 table 3. experimental result of boiling water with aluminum cookware mwater mlpg temperature (°c) time (gram) (gram) flame outer cookware inner cookware (s) 500 4 604 234 233 150 600 5 628 236 235 187.8 700 6 626 237 236 211.7 800 6.7 627 242 241 233.3 1000 7.5 628 243 242 250 table 4. energy consumption for heating water with enamel cookware mwater enamel aluminium cookware cookware mlpg energy mlpg energy (gram) (gram) (kj) (gram) (kj) 500 4.53 213.31 4 188.36 600 5.43 255.69 5 235.45 700 6.3 296.66 6 282.54 800 6.7 315.5 6.7 315.5 1000 8.63 406.38 7.5 353.17 3.3 energy efficiency and emission rate based on the calculation, apparently the cooking efficiency for both cook wares is increased as the increasing of water in cookware. based on table 1, 2 and 3 all temperature is relatively constant in each experiment, but the contact area is increased when the volume of water is increased. it is accordance with conduction heat transfer equation which implies that the heat transfer will be increased when the contact area is enlarged. the graph the efficiency is shown in figure 2. the average efficiencies which are yielded by enamel and aluminum cookware are 69.95 % and 75.34 % respectively. even though these materials have significant different thermal conductivity (discussed in next part of this paper), their efficiency is not too significantly different. apparently, the energy efficiency is not only determined by thermal conductivity. there are many factors which affecting the efficiency of heat transfer, such as thickness and shape of cookware. table 5. the amount of energy adsorption by water and its energy efficiency. mwater efficiency caloric energy enamel aluminum (gram) value adsorb cookware cookware (kj/kg) (kj) (%) (%) 500 4.18 144.35 0.68 0.77 600 173.22 0.68 0.74 700 202.09 0.68 0.72 800 230.96 0.73 0.73 1000 288.7 0.71 0.82 generally aluminum has weaker mechanical properties than cast iron and stainless steel. it is causing aluminum cookware needs a thicker surface than other cookware materials. because of that, there are many solutions to increase the heat transfer efficiency. the example solutions are by reducing the ratio of cookware diameter to flame diameter or decreasing cookware’s distance to its heat source (hannani et al., 2006). other research also reveals that a thin enameled cast iron can have better efficiency than aluminum cookware (villaćıs et al., 2015). air emission is other issue relates to fuel consumption. the emission can be categorized by the impact of pollutant to the environment. the degradation of ambient/indoor air quality and the increasing of ambient air temperature has become the biggest issue. since the energy efficiency of cooking by using enamel and aluminum cookware do not different significantly, the percentage increase in emission rate is also relatively low at 8,18 %. considering the health © 2019 the authors. page 130 of 132 pramadhony et. al. indonesian journal of environmental management and sustainability, 3 (2019) 128-132 table 6. emission rate of cooking activity by using gas stove and traditional stove. type enamel cookware of fc (kj) emission rate stove efp afp prameter efp afp gas stove 297.51 275 co2 (g) 18.77 17.35 co (mg) 5.95 5.5 traditional 5435.51 5024.28 co2 (g) 608.78 562.72 wood stove co (mg) 21742.04 20097.11 figure 2. graph of energy efficiency of the cookwares table 7. thermal conductivity of water heating with enamel cookware ∆t time q a k (°c) (s) (kw) (m2) (w/m°c) 5 160 0.903 3.40e-02 15.94 6 191 0.908 3.79e-02 11.99 6 218.7 0.925 4.11e-02 11.25 5 233.3 0.991 4.40e-02 13.51 6 260 1.111 4.96e-02 11.2 average 12.78 benefit of enamel coating on cookware, this cookware is very feasible to be used especially for cooking acid food. in addition, the focus consideration of emission rate should be focused on the technology and type of fuel. in indonesia there are many people still use traditional wood stove. it has bad efficiency and emits a huge hazardous gas concentration. according report of emission inventory in prabumulih, the consumption of wood is 18.27 higher than lpg (klhk, 2016). the emission rates in four conditions are shown in table 6. 3.4 thermal conductivity enamel coating affects cookware’s thermal conductivity property. this property is simply calculated by using heat transfer equation (eq. 1). based on the calculation in table 7 and table 8, aluminum cookware has better thermal conductivity than enamel cookware. the temperature difference between outer wall and inner wall of cookware proves the significant difference of thermal conductivity betable 8. thermal conductivity of water heating with aluminum cookware ∆t time q a k (°c) (s) (kw) (m2) (w/m°c) 1 150 0.963 3.40e-02 84.99 1 187.8 0.923 3.79e-02 73.14 1 211.7 0.955 4.11e-02 69.73 1 233.3 0.991 4.40e-02 67.55 1 250 1.156 4.96e-02 69.86 average 73.06 tween aluminum (± 1 °c) and enamel (5 6 °c) cookware. the calculations state the average of aluminum thermal conductivity is 73.06 (w/m °c) and enamel cookware is 12.78 (w/m °c). actually thermal conductivity value is depend on temperature and phase of the material. aluminum material thermal conductivity would be decreased when the temperature is increased. in solid phase, aluminum thermal conductivity is 150 210 (w/m °c) (valencia & quested, 2008). this range value is different to the result in table 7 and 8. the difference result with the standard value could be caused by the limitation of thermometer. in order to obtain better result, it needs a more accurate and precise thermometer especially in high temperature. 4. conclusions an experimental study has been conducted to investigate the influence of enamel coating on a cookware. there are two different material of cookware investigated in order to find out the performance. the parameters described in this research involve energy efficiency, thermal conductivity and the emission rate. in addition this research also comparing the emission when the cooking activity use traditional wood stove which is still used by many people in indonesia. energy efficiency is calculated by divides energy input from burning process by useful energy which adsorbed by water. based on the calculation above the efficiency of enamel and aluminum cookware are 69.95 % and 75.34 % respectively. the efficiencies of enamel and aluminum cookware above are influenced by thermal conductivity, where the © 2019 the authors. page 131 of 132 pramadhony et. al. indonesian journal of environmental management and sustainability, 3 (2019) 128-132 average thermal conductivity of enamel and aluminum cook wares are 12.78 (w/m °c) and 73.6 (w/m °c) respectively. furthermore, all these efficiencies are increased when the amount of water on cookware increased. the addition of water enlarges the contact area between outer wall and inner wall of the cookware. as a consequence, the conduction heat transfer which occurred in solid material is also increased. even though thermal conductivity of enamel cookware is much lower than aluminum cookware, the efficiency between two cookwares is not so different because the efficiency is influenced by many factors such as thickness, shape of cookware and distance between flame and cookware. the most dominant factors on efficiency and emission rate which should be considered are type of fuel and technology. the using of traditional wood stove is should be replaced, because it consumed large of energy inefficiently and emits much higher of carbon monoxide. references esdm (2013). konversi mitan ke gas. technical report, kementerian esdm ganesan, l. j., d. e. selvaraj, and j. ramathilagam (2013). experimental analysis of thermal conductivity of enamel filled with micro and nano composite of sio2 and tio2. interantional journal of advance research in electrical, electronics and instrumentation engineering, 2(7); 2907–2912 hannani, s. k., e. hessari, m. fardadi, and m. k. jeddi (2006). mathematical modeling of cooking pots’ thermal efficiency using a combined experimental and neural network method. energy, 31(14); 2969–2985 klhk (2016). inventarisasi emisi kota prabumulih 2016. prabumulih mart́ınez-gomez, j., g. guerrón, and r. a. n. c (2016). corrosion analysis in different cookware materials. international journal of engineering trends and technology, 34(8); 389–393 oldring, k. p. and u. nehring (2007). packing materials 7. metal packing for foodstuffs. international life sciences institute sajid, m., m. ilyas, c. basheer, m. tariq, m. daud, n. baig, and f. shehzad (2014). impact of nanoparticles on human and environment: review of toxicity factors, exposures, control strategies, and future prospects. environmental science and pollution research, 22(6); 4122–4143 villaćıs, s., j. mart́ınez, a. riofŕıo, d. carrión, m. orozco, and d. vaca (2015). energy efficiency analysis of different materials for cookware commonly used in induction cookers. energy procedia, 75; 925–930 © 2019 the authors. page 132 of 132 introduction experimental section materials methods results and discussion energy consumption energy adsorption energy efficiency and emission rate thermal conductivity conclusions indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article doi: 10.26554/ijems.2017.1.1.1-51 received: 12 september 2017 accepted: 28 november 2017 *corresponding author email: dina.gofar@yahoo.co.id fish and fisheries in flood plain swamp in middle part of musi river dina muthmainnah1,*, abdul karim gaffar2 1research institute for inland fisheries and extensions palembang 2faculty mathematic and natural science, pgri university, palembang abstract floodplain area is a very dynamic water system where the influence from terrestrial and river is high. this area is recognized as feeding, nursery and spawning ground of some fishes. capture fisheries in this area is frequently occurred by using some of specific fishing gears which related to dynamic pattern of aquatic environment, such as water level, current, and physical-chemical aspects of water. the research was conducted in order to evaluate fish caught composition and fishing activity in floodplain swamp in middle part of musi river by survey method. the result showed that 45 species of fish were caught and nine kinds of fishing gears were used by fishers. gill nets were used in whole year, while seine were used only in the peak of dry season. intra-annual variations of swamp water flow can modify the distribution and migratory pattern of fish species, with direct effects on fish catches. keywords: fish caught composition, fishing gears, floodplain swamp 1. introduction river and its floodplain were considered as complex and dynamic aquatic ecosystem where alternately and periodically changes from aquatic to terrestrial ecosystem [1]. main sources of nutrients come from decomposed plant litter of macrophytes gave high fertility of aquatic ecosystem. many kinds of invertebrate organisms were involved in decomposition processes would provide natural food for fish [2]. in indonesia, inland swamp is around 14 million hectares found in all big islands such as sumatra, kalimantan, sulawesi and irian. floodplain swamps are found in south sumatra province as lowland area. the characteristic of lowland area is in wet season inundated by water from the adjacent musi river forming any kinds of water bodies. floodplain swamps play a vital role in providing abundant fish food, and one of the most important characteristics of floodplain swamps are their combination of shallow water and thick vegetation, which provides nursery habitat for young fish [3]. together with phytoplankton and benthic algae, organic matter from the emergent vegetation is the source of primary production in floodplain swamps [4]. association of aquatic vegetation and invertebrate animals provide food and shelter for many species of fish [5]. the local people who live surrounding the area engaged primarily in fishing during wet season and farming during dry season. the previous study in sekayu district south sumatra province focused on the fish diversity found 20 [6] species in the mainstream and 35species in the floodplain, while there were 233 species of freshwater fishes in south sumatra waters [7-9]. during the wet season, the lowland swamp water becomes a productive fishing ground. capture fishery range from small subsistence efforts to commercial one, using any form of fishing gears and multi species target. fisheries activities start at the beginning of rainy season when fish habitually migrate from the main river either for grazing and for`spawning and finish at the mid of dry season when the fish already going back to the main river and the rest have been totally caught out [10]. this paper provides a description of the small-scale fisheries of floodplain swamp in middle part of musi river, with emphasis on fish diversity and fishing activity. 2. experimental section research was carried out in survey descriptive method by direct observation on fishing activity in a selected area in middle part of musi river of sekayu sub district (1030:50’:04” to 103o:51’:56,8” e and 02o:53’:59,7” to 02o:55’:05,8” s). direct observations were done to find out informations on fishing practices and species diversity of fish cought by different types of gears. fishing gears recorded base on its size, form, materials, and how to operate [11,12]. schedule of operation of each kind of fishing was recorded from agustus 2015 to july 2016. fish cought by each type of gears were identified base on morphometric and meristic data and comparing to reference books [13,14]. hydrological characteristics such as water flow and water level were directly measure during survey time. 3. results and discussion 3.1.fish diversity fish caught during one year in research location composed of 45 species, where family of cyprinidae have the highest diversity of 17 species, while bagridae, channidae and anabantidae have four species respectively. beside using as human food there were two species of fish considered as ornamental fish, balantiocheilus melapterus and chromobotia macracanthus as listed in table 1. fishing intensity in a water body was depend on natural productivity which are related to environmental conditions and human activity around the water body [15]. muthmainnah et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 1-5 doi: 10.26554/ijems.2017.1.1.1-52 3.2. fisheries activity 3.2.1. fishers there are two types of fishers, individual fisher who work individually using simple fishing gears, and grouped fishers who work in team of 3 to 10 people using more complex fishing gears. individual fisher usually the native inhabitant and did not need any license for fishing activity, while grouped fishers not only the native inhabitant but also migrate fishers and to exploit a water body they should have a “license” from local government. the license could be found through auction system which is conducted by village major on early january every year. in the research location, 6 fishers were individually work using pot traps, long lines, gill nets and pole and line, they work as fishers only during rainy season. a group of 10 fishers was working together using more complicated fishing gear such as tabel 1. composition of fish caught in floodplain swamp of musi river no family species common name local name 1 cyprinidae osteochilus vittatus bonylip barb palau 2 cyclocheilichthys apogon beardless barb seberas 3 leptobarbus hoevenii hoven’s carp jelawat 4 barbonymus schwanenfeldii tinfoil barb lampam 5 puntioplites bulu tebengalan 6 puntigrus tetrazona sumatra barb pirik elang 7 osteochilus melanopleura aro 8 barbichthys laevis sucker barb bentulu 9 osteochilus microcephalus buing 10 thynnichthys thynnoides damaian 11 labiobarbus ocellatus lambak usang 12 hampala macrolepidota hampala barb sebarau 13 balantocheilus melapterus tricolor sharkminnow puntung hanyut 14 rasbora sp seluang 15 haludaria fasciata melon barb semuringan 16 labiobarbus festivus signal barn siumbut 17 labeo chrysophekadion blackshark minnow sihitam 18 channidae channa pleurophthalmus snakehead bujuk 19 channa striatus striped snakehead gabus 20 channa micropeltes indonesian snakehead toman 21 channa melasoma black snakehead serkoh 22 anabantidae anabas testudineus climbing perch betok 23 trichopodus pectoralis snakeskin gourami sepat siam 24 trichopodus trichopterus three spot gourami sepat mato merah 25 trichopodus leerii pearl gourami sepat daun buluh 26 helostomatidae helostoma temminkii kissing gourami tembakang 27 belontidae belontia hasselti malay combtail selincah 28 bagridae mystus gulio long whiskers catfish lundu 29 mystus micracanthus biran 30 hemibagrus nemurus asian redtail catfish baung 31 mystus nigriceps twospot catfish beringit 32 clariidae clarias macrocephalus bighead catfish lele 33 silurudae wallago leerii tapah 34 kryptopterus schilbeides lais kocor 35 kryptoperus cryptopterus lais tapah 36 pangasidae pangasius macronema riu-riu 37 pangasius polyuranodon juaro 38 cobitidae chromobotia macracanthus clown loach kejublang 39 pristolepididae pristolepis grootii indonesian leaffish kepor/sepatung 40 nandidae nandus nebulosus bornean leaffish setambun 41 mastacembelidae mastacembelus unicolor spinny eel tilan 42 cynoglossidae cynoglossus feldmanni river tonguesole lidah 43 tetraodontidae tetraodon sp buntal 44 chandidae parambassis wolffii duskyfin glassy perchlet sepengkah 45 eleotridae oxyleotris marmorata marble goby betutu muthmainnah et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 1-5 doi: 10.26554/ijems.2017.1.1.1-53 funnel filtering device, barrier traps, fence and traps, and seine, they work as full time fishers. 3.2.2.fishing gears floodplain fisheries are known as multispecies and multi gears fishery, where there are no specified fish target and fishers use many kinds of fishing gears, commonly traditional and self made gears [16]. fishing gears operated in musi floodplain along year round were practiced in a squence according to water level fluctuations. during the early of flooding season and at the end wet season the main fishing gears is fence barrier traps, a static trap filtering fishes in lateral migration from the plain to river and vice versa. during high water level with slow current, fishes moving inside the swamp for feeding, the main gears are the ”set and wait gears” such as gill nets, pot traps, and long lines. in dry season where only some water pools still exist and almost all of fishes crowded in relatively small area of pool, fishing activity were use chasing gears such lift nets and push nets or hoovering by seine net. type and operating method of fishing gears used in musi flood plain was showed in table 2. these four basic categories of floodplain river gear types have the following characteristics [17]: set-and-wait fishing gears include gill nets, long lines and individual fish traps. these are usually used in open waters where they are not entangled by weed or disturbed by strong flows. such gears generally take a small catch per unit of effort but require relatively little effort, and can be used over a long season or even continue to be effective throughout the whole year. chasing gears such as lift nets, push nets, and spears are mainly used in the flood season, and involve more active pursuit of the fish by fishers, preventing their involvement in other parttime activities. they are a relatively inefficient fishing method at this time, due to the wide dispersal of the fish in the open floodplain waters. barrier gears are used on fish migration routes, particularly where water flows off the floodplain into the rivers or permanent pools of the dry season. fish are trapped along such routes in some type of fyke chamber which is easy to enter but then difficult to escape from. such fykes may be fished in various ways: several small box traps may be placed along a channel for example, or long fences may be used to direct fish into one central holding chamber. hoovering gears are used in the dry season to extract or ‘hoover’ those fish stranded in dry season water bodies. at this time of year, fishing waters may either be seine-netted in one or more wide sweeps, or even completely drying so that the fish can be collected by hand. proportion of fish catch by each kind of fishing gears was shown in figure 1. barrier trap was the most effective gears which is yielding 40% of total catch, while long lines yields only 3% of total catch. gillnets which were operated from february to october yields 32% of total catch and set pole and line yields 21 of total catch. freshwater swamp which are inundated by nutrient-rich water from river resulting in high productivity [18]. 3.3. relationship of water level fluctuation and operated fishing gears figure 2 shows the sequence of fishing gears operated according to water level fluctuation. any type of fishing gear was operated according to dynamic of water level or water flow which is influence to fish movement. during the initial of flooding the fish tend to migrate laterally from river to plain and at the end of rainy season they move from flood plain to river. set longlines, gilnets, funnel filtering device were operated during high water level while seine operated only during low water level with water depth less than 2 meters. cast net and pole and line were used within whole year. gill nets with different mesh size could operated within a table 2. kinds of fishing gears operated in musi floodplain no fishing gear mode of work category 1 hook and line (tajur) passive, bait, selective, set in night time. set and wait set longlines 2 (rawai) passive, bait, selective, with many hook, set and wait gillnets set in day a and night time. 3 (jaring) passive, selective according to mesh size. set and wait filtering funel (corong) 4 silindric pot traps (bubu) passive, filtring fish in fast water current, non selective. set and wait rectangular pot traps (bengkirai) passive, traping fish in grazing area, selective, usually with bait. 5 cast net (jala) passive, trap, selective. set and wait 6 barrier traps (empang) active, non selective, operated in open area, supported by canoe. set and wait seine passive, fence barrier 50 100 m long with box traps, non selective. 7 (kerakat)w active, moved by 3 5 people to make a small circle as fish room, nonselective. chasing 8 barrier 9 hoovering muthmainnah et al. 2017 | indones. j. env. man. sus. 1 (1) 2017: 1-5 doi: 10.26554/ijems.2017.1.1.1-54 whole year (january – december), in flowing water or in stagnant water. long lines were operated only during high water (march – june), while set pole and line (tajur) were operated during the end of wet season (april – august) in slow flowing water. funel filtering device was used in fast flow water, filtering fish which are swing against water current, during wet season (february – march and november december). barrier trap was used to catch migrating fish from plain to river during the initial of dry season (june – july) and seine was used during low water level (july – august). recent studies also found that the fishers using different fishing gears related to fluctuation in water depth [19, 20]. during high water level, pole and line, long line, gill nets are favorable fishing gears in swamp forest, while during low water level seine, cast net, lift net and drag net are the favorable gears. barrier trap and fence are favorable during period with drastic change of water level when fishes move out and enter the swamp. pot traps with some different shapes and different materials were used in a whole year. at the beginning of dry season (march to july) when water depth was around 1.5 to 2.0 m, the main gears are pole and line (“tajur”), long lines, and gill nets. from july to mid of october with water depth only around 1.0 m the principal fishing gears used were barrier traps, fence and trap, and seine. long lines were used during high water level (february – march and october – december). funnel filtering device only used during high water with fast flow (february – april). similar fishing activities were also seen in floodplain around lempuing river channel. river barier with funnel trap use for fishing migratory fishes along the lempuing river especially during the fast flowing water in early flood season. significant catches were also observed during the june/july early reflooding at the upstream sites, but less so at the downstream savanna river sites. after this time, very few fish were caught in the riverine barriers during the second drawdown period, and over the dry season. in the subsequent early flood season, longitudinal migrants were again caught in riverine barriers though in smaller numbers, reflecting the catches taken over the dry season. the catches taken during this flood season confirm the ability of these barrier gears to catch whitefish on their spawning migrations. the mesh sizes used in fishing gears determine their selectivity towards small sizes of fish, and hence have a profound effect on the overall levels of exploitation of fish stocks [21]. on the positive side, the use of small meshed gears increases the number of small fish species which are accessible to the fishery: on the negative side, they also take the small fry of other larger fish species. the different gillnet mesh sizes caught great variation in their size class catch distribution of fish [22]. while a fishery with small meshed gears may be sustained by the smaller fish species, there is an associated danger that the larger fish will become overexploited and decline. 4. conclusion flood plain swamp is a dynamic ecosystem where it is become terrestrial habitat during dry season and aquatic habitat during rainy season. the swamp has the high fish diversity and has been utilized as fishing ground. hydrological variations can affect fish at their distribution and temporal scales. intra-annual variations of swamp water flow can modify the distribution and migratory pattern of fish species, with direct effects on fish catches. in the long term, variations in the hydrological fluctuation can influence the population dynamics of fish by acting on their reproductive and recruitment processes, changing the relative 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[20] muthmainnah, d., z. dahlan, r.h. susanto, a.k. gaffar and d.p. priadi. utilization of freshwater fish biodiversity as income source of poor rural people (case study in pampangan subdistrict of south sumatra province, indonesia). in asia-pacific biodiversity observation network: aquatic biodiversity conservation and ecosystem services. editor: s. nakano, t. yahara, & t. nakashizuka. ecological research monographs. springer science. singapore. pp 89-100, 2016. [21] hamely, j.m. 1975, review of gillnet selectivity. journal of fish research. 32: pp1943-1969. [22] chindah, a.c. and c.c.b.tawari. 2001, comparative study of different gillnet mesh size in the exploitation of bonga fish (ethmalosa fimbriata) and sardines (sardinella eba) in brass coastal waters, bayelsa state, nigeria. journal of appl. science environment management. vol. 5 (1): pp17-24. title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper the change of nutrients rations quality of feed fermented with different moisture content miksusanti1, sofia sandi2*, fitra yosi2, eli sahara2, nasir rofiq3 1department of chemistry, faculty of mathematics and natural science 2department of animal science, faculty of agriculture, university of sriwijaya 3agency for the assessment and application of technology (bppt) centre for agriculture production technology *corresponding author e-mail: sofiasandi-nasir@yahoo.com abstract the change of nutrients on rations made from local raw materials was evaluated after being fermented in various moisture contents. the experiment used completely randomized design comprise of 5 treatments and 3 repetitions. the treatments were p0 (fermentation without moisture), p1, p2, p3 and p4 (fermentation in 40%, 50%, 60% and 70% moisture content). variables observed were total microbe, total acid, acidity (ph) and the change of dried matter content, organic matter, crude protein, crude lipid, crude fiber and nitrogen-free extract. the result showed that there are statistically significance differences (p<0.05) between local raw materials rations fermented in different moisture contents towards variables observed. local raw materials rations fermented in 50% moisture content exhibited good nutrients quality indicated by increased in dried matter content, organic matter, crude protein, nitrogen-free extract, total microbe and total acid while crude lipid, crude fiber and acidity (ph) showed a decreased. keywords fermentation, nutrient change, moisture content, local raw material rations received: 20 may 2019, accepted: 14 june 2019 https://doi.org/10.26554/ijems.2019.3.2.47-53 1. introduction rations is an important factor in supporting duck broiler farms. the cost for rations approximately 70% of total production budget in an intensive animal husbandry. rations cost can be reduced by optimizing local raw materials obtained from agricultural and industrial wastes. naturally, wastes from agriculture and industry has not been optimally utilized nevertheless one can get it easily. the drawback issues of wastes utilization as rations are highly crude �ber content, low digestible nutrients and the presence of anti-nutrients substance. various waste processing can be carried out prior used as ration such as fermentation. fermentation is a process of storing substrates in anaerobic or aerobic conditions with embedded microbes in it. fermentation process would reduce crude �ber content, increase digestible value and diminish anti-nutrients substance of local raw materials hence can be used as rations (pamungkas, 2011) . inoculant widely used with the ability to hydrolyze starch in fermentation chamber is saccharomyces cerevisiae contain in yeast. saccharomyces cerevisiae is anaerobic facultative, which can live in both aerobic and anaerobic systems and able to break up glucose to obtain energy. fermentation using saccharomyces cerevisiae reach optimum result after 7 days. rations digestibility increased with yeast addition 0.3% into fermentation substrate with moisture content 50% (bidura et al., 2012; martindah and bahri, 2016) . moisture content contribute signi�cantly on growth of microbe in fermentation process. metabolic reaction of microbial cell is assisted by water to transport nutrients into the cell as well as metabolic product transported out of cell. each microbe has its own optimum moisture content to grow and regenerate. low moisture content in the growth media hamper microorganism activity which in turn decrease the chance to degrade �ber and crude lipid components in the substrate. high moisture content on the other hand tend to decrease medium porosity causing di�culty in aeration process and mass transfer on microorganism metabolism (vu et al., 2010) . 2. experimental section 2.1 materials preparation and formulating rations preparation of eggshell powder was initiated by washing dirt and removing membranes embedded. the eggshell was then soaked in hot water (100 °c) for 15-30 minutes, dried and grinded to obtain �ne particles. preparation of powder from leaf of lamtoro, kale and cassava were conducted by cutting the leaf from its stalk. the leaf was dried, grinded and sieved to https://doi.org/10.26554/ijems.2019.3.2.47-53 miksusanti et. al. indonesian journal of environmental management and sustainability, 3 (2019) 47-53 collect powder in �ne texture. similar procedure was carried out on other rough raw materials such as corn, coconut pulp, water hyacinth, palm kernel cake and golden snail. raw materials prepared in �ne powder from the previous step were weighed in certain amount. the powders were mixed initially from smallest composition i.e. premix by eggshell powder and then water hyacinth powder followed by palm kernel cake powder, kale leaf powder, cassava leaf powder, coconut pulp powder, lamtoro leaf powder, golden snail powder and �nally, corn powder. the portion of each powder was displayed on table 1 while rations nutrients content was appeared on table 2. table 1. local raw material composition in rations formulation raw materials composition (%) fine corn 57 coconut pulp powder 5 palm kernel cake powder 4 golden snail powder 17 kale leaf powder 4 water hyacinth powder 3 cassava leaf powder 4 lamtoro leaf powder 5 eggshell powder 0.5 premix 0.5 total 100 table 2. nutrient composition of rations nutrients composition metabolic energy (em) kcal/kg 2921.39 crude protein (%) 17.11 crude �ber (%) 9.43 crude lipid (%) 7.82 p available (%) 0.3 ca (%) 0.73 methionine (%) 0.21 lysin (%) 0.53 remark: analysis result from laboratory of nutrition and animal feed university of sriwijya 2016 2.2 moisture content determination and the process of fermentation moisture content was determined by analyzing the rations dried matter value prior fermentation, so moisture can be calculated accordingly. porcelain crucible was pre-heated to 105 °c oven for 1 hour and then placed in desiccator for 30 minutes. porcelain crucible was weighted and mark as a. 5 grams samples (b) placed into the crucible and heated to 105 °c for 24 hours and then cooled in desiccator for 30 minutes. the �nal weight of porcelain crucible with sample were measured and mark as c. moisture content was calculated according to following formula (aoac, 1995) : moisturecontent(%)= b−(c − a) b x100% driedmatter(%)= 100%−moisturecontent(%) water to be added was calculated according to formula (rostini et al., 2009) : rations moisture content (g) = bkrations(%) bkrationsprepared(%) x rations in total (g) water to be added (ml) = rations moisture content (ml) – rations in total (ml) fermentation process was conducted according to previous report (bidura et al., 2012) with modi�cation i.e. rations was added by warm water (50–60 °c) based on previous researcher (rostini et al., 2009) , formula. rations and water were stirred, and air cooled for 5 minutes. yeast was added in form of �ne particles 0.3% by weight of rations and then homogenized. the tray containing fermented rations with various moisture content was weighted and covered with aluminum foil and stored for 7 days (kusumaningrum et al., 2012) . after fermentation completed, the cover was removed, and the sample was dried in oven 45 °c for 6 hours. rations was then subjected to analysis of crude protein, crude lipid and crude �ber. 2.3 research method and data analysis research was planned by using completely randomized design with 5 treatments and 3 repetitions. the rations used in this research was marked as: • p0 = rations fermented without water addition (control) • p1 = rations fermented with moisture content 40% • p2 = rations fermented with moisture content 50% • p3 = rations fermented with moisture content 60% • p4 = rations fermented with moisture content 70% data was analyzed by using analysis of variance and if the treatment showed statistically signi�cance di�erence, data was further analysis with duncan’s multiple range test. 2.4 variable observed the observed variable was dried matter, organic matter, crude protein, crude lipid, crude �ber, nitrogen-free extract, microbe total, total acid and acidity (ph) (aoac, 1995) . nutritional value was calculated according to following formula (nelson and suparjo, 2011) : nutrition value change (%) =(axbkoxco)−(bxbktxct) (axbkoxco) x100% note: a = rations weight before fermentation (g) b = rations weight after fermentation (g) bk0 = dried matter before fermentation (%) bkt = dried matter after fermentation (%) c0 = nutrition value before fermentation (%) ct nutrition value before fermentation (%) © 2019 the authors. page 48 of 53 miksusanti et. al. indonesian journal of environmental management and sustainability, 3 (2019) 47-53 3. results and discussion average value of microbe total, total acid and ph analyzed from samples are display in table 3. rations samples were treated and fermented with di�erent moisture content as described on procedure above. analysis of variance showed that rations fermented in different moisture content has signi�cance di�erence (p<0,05) towards microbe total. furthermore, analysis result exhibited that rations with 50% moisture content has higher microbe total compare to p0 and p1 but showed no statistically signi�cance di�erence towards p3 and p4. 50% water in fermentation process presume to provide optimum condition for microbe growth. high level of moisture content moreover, hampered aeration and mass transfer on metabolism activity of corresponding microorganism, while low level of moisture content will make microorganism di�cult to grow on the media (vu et al., 2010) . physical quality of rations fermented in 40% moisture content indicate slightly sour smell, light brown and dry texture. the rations fermented in 50% moisture content showed similar appearance both on smell and color but has wet texture. 60-70% moisture content fermentation resulted rations with strong sour smell, pale color and highly wet texture. the last two results indicate a decrease in nutrient quality along with growth of harmful microbe. julendra et al. (2012) reported harmful microbe could cause damage on rations quality which can be seen from its color, smell change and decay process due to chemical composition modi�cation. furthermore, good quality rations physically can be assessed from sour smell, light brown color and wet texture (saad et al., 2016) . the result indicated that microbe was grew in lag phase up until 40% moisture content. the number of microbe growth was not increased at this phase. lag phase de�nes as slow growth of microbe due to adaptation and adjusting themselves to the environment. at 50-70% moisture content, the microbial growth is in stationary phase i.e. growing rate equals to mortality rate hence at this phase, the microbe growth is constant (mathivanan et al., 2006) . rations prepared from local raw materials with various moisture content according to analysis of variance is showed statistically signi�cance di�erence towards total acid (p<0.05). further test indicated that 50% moisture content treatment has distinctly higher total acid compare to p0 and p1 but not signi�cantly di�erent with p3 and p4. the increase of total acid was assumed due to high moisture content of the substrate which prompt the microbial growth and produced organic acids. microbes used simple sugars in fermentation process to produce organics acids (anggraeni and yuwono, 2014) . total acid titrated is total acids both dissociated and undissociated henceforth total acids bonds to naoh can be identi�ed. our work obtained total acid at 1.47-2.70% higher than reported previously [4] whom obtained total acid of cacao beans pulp fermented with yeast at 0.23-0.62%. during fermentation process, organics acid is formed including lactic acid, acetic acid and butyric acid. these acids were produced due to acetobacter activity in the yeast which has oxidative character (feng et al., 2007) . fermentation with 50% moisture content smelled sour which indicate high lactic acids was produced. 60-70% moisture content further, smelled very sour which indicate acetic acids and butyric acids were produced. sour smell indicates the lactic acids formation while smelled very sour indicates the formation of acetic acids and butyric acids. analysis of variance conclude, rations made from local raw materials fermented with various moisture contents showed signi�cance di�erence towards ph (p<0.05). further statistical analysis reveals fermentation with 50% moisture content (p2) signi�cantly higher than p0 and p1 but not signi�cantly di�erent with p3 and p4. the rationale behind this fact is moisture can increase fermentation rate henceforth the higher moisture content, the more acids (low ph) rations obtained. the ph of fermentation is proportional to the total acid, which makes lower ph indicate total acids produced is higher. the decrease of ph started at 50% moisture content as the increase of total acids produced. phenomenon as the decrease in ph is accompanied with the increase in total acid on sago fermentation. ph was decreased due to fermentation aerobically produced oxygen which formed organic acids compound and a�ected ph value (chaing et al., 2010) . acidity scale (ph) is one of important factor in fermentation process (azizah et al., 2012) . in this research we found out the average of rations ph fermented in di�erent moisture content is 4.42-6.20. ph started to decrease at 50% moisture content through 70% i.e. 4.48-4.42. ph measured in cempedak skin fermentation to obtained bioethanol by using saccharomyces cerevisiae is 4-5. nutritional changes of rations were analyzed before and after fermentation in di�erent moisture content is displays in table 4. analysis of variance result concluded that rations fermented in di�erent moisture content statistically signi�cance di�erence (p<0.05) towards crude protein content. moisture a�ects the increase and decrease of crude protein content resulted from microbial activity. further test exposes rations p2 (50%) higher signi�cantly (p<0.05) on its crude protein compare to others. p1 also showed signi�cance di�erence (p<0.05) compare to other treatment while p0 reveals signi�cance difference compare to other (p<0.05). p3 has no signi�cance di�erence (p>0.05) compare to p4 in the decrease of crude protein content. the highest change of crude protein content was discovered on p2 i.e. 5.65% of initial value (17.11% into 17.60%). the condition of p2 henceforth indicate the optimum condition among other treatments for saccharomyces cerevisiae. water obviously help microbial growth and metabolism in fermentation. the increase of crude protein strongly associated with microbial activity. our analysis also found out that microbe total at p2 is 7.20x1010 cfu g−1 while control (p0) shows 3.23x1010 cfu g−1. the increase in amount of microbe directly correlated to the increase of protein-rich microbial mass © 2019 the authors. page 49 of 53 miksusanti et. al. indonesian journal of environmental management and sustainability, 3 (2019) 47-53 table 3. average value of microbe total, total acid and ph rations prepared from local raw materials with di�erent moisture content on fermentation treatment variable microbe total (1010 cfu g−1 ) total acid (%) ph p0 323a±1.08 1.53a±0.06 6.20b±0.05 p1 3.20a±0.09 1.47a±0. 04 6.27b±0.10 p2 7.20b±1.08 2.42b±1.02 4.48a±0.02 p3 7.37b±1.23 2.57b±1.07 4.46a±0.03 p4 7.43b±1.11 2.70b±1.18 4.42a±0.04 note: di�erent superscript in the same column indicate signi�cance di�erence. table 4. nutritional changes of rations fermented from local raw materials treatment change crude protein crude lipid crude �ber dried matter organic matter nfe (%) (%) (%) (%) (%) (%) p0 0.01c±0 .90 0.02a ±0.86 -0.01b±0.94 0.01c±0.03 0.01c±0.03 1.87c±0.12 p1 -2.93b±0.50 2.5bc±0.94 3.95c±0.27 -0.28b±0.01 -0.42b±0.04 -6.76b ±0.22 p2 -5.65a±0.20 4.55c±0.66 5.68d±0.56 -2.70a±0.15 -3.72a±0.13 -11.85a±0.27 p3 1.54d±1.19 2.06ab±1.98 -1.85a±1.33 2.98d±0.13 3.48d±0.07 13.66d±0.06 p4 2.53d±0.48 1.26ab±0.86 -3.06a ±0.23 4.42e±0.01 5.88e±0.06 19.71e±0.20 and so does crude protein content. mass of cell composed of protein compound which makes large amount of microbe correspond to large amount of protein content (wajizah et al., 2015) . fermentation process drives microbe to produced enzyme used to degrade complex compound into simpler one and to synthesis protein and protein enrichment. protein enrichment was achieved from protein synthesis by microbe which produced degradation enzyme used on converting complex compound into smaller one (heres et al., 2003) . crude protein was decreased on p3 and p4. high content of moisture tends to accelerate not only the growth of useful microbes but also harmful microorganism, this situation caused microbial growth to increase microbial mass is hampered. high moisture content can reduced substrate porosity which in turn decrease oxygen exchange and increase risk of bacterial contamination (juliarti and alfaizah, 2013) . physical quality appearance of our product exhibited the possibility of nutrient quality reduction due to the existence of green and dark brown mycelia fungus, smells very sour, pale color and very wet texture on the fermented rations. similar occurrence i.e. contamination of mold producing-toxin caused damage and made the rations quality decline physically, chemically and biologically and reduced palatability and the diminish of nutrient value (martindah and bahri, 2016) . analysis of variance con�rmed that moisture content treatment statistically signi�cance di�erence (p<0.05) towards crude lipid content. this fact strengthens the notions that moisture content indeed a�ects the reduction of crude lipid caused by microbial activity. statistical test further veri�ed that the treatment of rations at p3 not signi�cantly di�erent (p>0.05) to p0 and p4 (p>0.05). p1 however is largely decrease crude lipid in signi�cant way (p<0.05) compare to p3 and p4 but lower signi�cantly compare to p2 (p<0.05). p2 has crude lipid much lower signi�cantly (p<0.05) compare to p1. the highest crude lipid change is obtained at p2 i.e. 4.55% of initial value (7.82% into 7.27%). p2 with 50% moisture content was able to provide optimum condition for microbe to hydrolysis complex crude lipid into smaller volatile fatty acids. the presence of water in fermentation process produced volatile acids i.e. sort chain fatty acids which easily to vaporize. crude lipid content of rations consists of glycerol, fatty acids and vitamin which is soluble in volatile fatty acids. water promote crude lipid hydrolysis into glycerol and free fatty acids (rostini et al., 2009) . moisture content treatment marks as p0, p1, p3 and p4 exhibited change of crude lipid content but not as high as p2. moisture in less or more than 50% seems to hinder microbial optimum growth. moisture plays important role in substrate decomposition process. substrate generally contain organic substance which is used by microbes for its growth and regeneration. saccharomyces cerevisiae utilize lipid in the substrate as energy resource on metabolism process in the cell. low moisture content tends to hamper nutrient transport hence microbial growth is slower and cannot degrade crude lipid optimally. high moisture content further reduces decomposition rate of substrate and limited nutrient availability for microbe. mass transfer in metabolic process also harder to carried out under high content of moisture. © 2019 the authors. page 50 of 53 miksusanti et. al. indonesian journal of environmental management and sustainability, 3 (2019) 47-53 treatment of moisture content con�rms to give signi�cance di�erence (p<0.05) towards crude �ber content change according to analysis of variance result. statistics proved that moisture a�ects the increase and decrease of crude �ber content due to microbial activity. further test result informed that the signi�cance di�erence achieved highest value at p2 towards the decrease of crude �ber. it is also can be concluded that p1 showed signi�cance di�erence (p<0.05) to other treatment as well as p0 to other treatments while p3 showed no signi�cance di�erence (p>0.05) to p4 towards increment of crude �ber content. the highest crude �ber content decline by treatment p2 i.e. 5.68% (9.34% into 8.66%) indicate microbial activity runs optimally under 50% moisture condition. moisture takes important part in biosynthesis and enzyme secretion (idiawati et al., 2014) . saccharomyces cerevisiae showed secondary activity i.e. produced cellulase which assists complex compound degradation into smaller compound (nuryana et al., 2016) . the mold also able to hydrolyze cellulose to form glucose and indirectly reduced crude �ber content. cellulose compose of carbohydrate, useful substrate for microbial growth as feed source (d et al., 2015) . treatment p3 and p4 exhibit increase of crude �ber content. hight content of moisture appears to prevent optimum activity of microbe to degrade crude �ber. total microbe in p4 was calculated as highest 7.43x1010 cfu g−1 . the microbe in this number allegedly is not the useful microbes which assisted fermentation. physically appearance exhibit there are harmful fungal mycelia formed in the substrate. the growth of fungal mycelia contributes to crude �ber mass in the fermentation media (samadi et al., 2015) . microorganism cell wall is �ber source which contribute �ber content on fermentation product (rostini et al., 2009) . analysis of variance result for moisture content e�ect on dried content change shows signi�cance di�erence (p<0.05). further test concluded the increase of dried content fermented in p2 treatment is higher (p<0.05) compare to p1. the decrease of dried matter found out on p4 with a larger decline compare to p3 and p0 (p<0.05). p2 increase the dried content by 2.70% from initial value before being fermented (90% into 95.02%) while p4 decrease the dried content by 4.42% from initial value before it fermented (90% into 87.73%). dried matter value raises when fermented in 50% moisture content. at this condition, oxygen di�usion presume to be optimal and provide a smooth process of heat exchange which cause moisture content decrease. during fermentation water used by microbes for metabolism activity. the activity prompt oxygen di�usion runs well and then decrease the content of moisture. another author described that dried matter of substrate increase due to microbial activity in solid medium used water in the substrate and made it less water to contained (saad et al., 2016) . dried matter decreased in p0, p3 and p4 treatments. fermentation in 60-70% moisture content caused rations dried matter to decrease. high content of moisture possibly hinders the oxygen di�usion which make heat transfer was disturbed and lower the activity and microbial growth. high moisture content can also hamper aeration process which a�ects evaporation and keep the rations moisture content stays high (juliarti and alfaizah, 2013) . p0 was found out to have its dried matter decreased. low content of moisture obviously inhibits microbial growth. the moisture plays important role on nutrient transport, chemical process and metabolic activity during fermentation (idiawati et al., 2014) . condition in lack of water decreased microbial growth as well as substrate degradation. throughout fermentation the component of rations was degraded by mold, typically carbohydrate to form glucose and by product such water which reduced dried matter content (bidura et al., 2012) . the variance was analyzed statistically and reveals that moisture content give signi�cance di�erence towards organic matter (p<0.05). further statistical test concluded organic matter increase in p2 which is higher than p1 (p<0.05). p4 displays decrease on its organic matter more than p3 and p0 (p<0.05). organic matter increases by 3.72% in p2 treatment compare to before fermented (94% into 94.9%) while organic matter decreases by 5.88% in p4 treatment compare to before fermented (94% into 92.55%) fermentation in 50% moisture content raise the organic matter indicate optimum microbial activity to produce enzyme which converts organic molecule into smaller compounds. the conversion of organic molecule produced simpler substances such as �ber, lipid and carbohydrate and increase organic matter of rations (nuryana et al., 2016) . moisture content of 60-70% in contrary decreases the organic matter. high level of moisture in fermentation tends to accelerate air exchange which promotes evaporation. droplets were formed on the tray and drips onto substrate surface and contribute to moisture content (feng et al., 2007) . this condition is assisting the accretion of harmful bacteria and prevents the optimum microbial growth. the increase of protein-rich microbial mass is therefore decelerated and lower one of organic mass source in the rations. physical appearance exhibits some fungus grew with sour’s smell, pale color and wet texture in the fermented rations. it had been reported that bacterial contamination cause decay on rations quality including color aberration, change of smell, and decomposition due to chemical composition modi�cation (julendra et al., 2012) . in addition, organic matter decrease throughout fermentation can be caused by harmful microbe proteolytic activity which grew during the process. calculation of total microbes showed that at p4, it contains 7.43x1010 cfu g−1. the change of dried matter and organic matter show similar tendency. the change of organic matter is aligned with the change of dried matter (nelson and suparjo, 2011) . calculation by using analysis of variance informed that moisture content show signi�cance di�erence towards nitrogenfree extract (p<0.05). further test con�rm rations p2 has nfe highest increased (p<0.05) compare to p1 while p4 has nfe lowest decreased (p<0.05) compare to p3 and p0. the nfe © 2019 the authors. page 51 of 53 miksusanti et. al. indonesian journal of environmental management and sustainability, 3 (2019) 47-53 increase by 11.85% from its initial value on p2 (50.36% into 54.85%) while nfe decrease by 19.71% from it initial value on p4 (50.36% into 42.30). microbial growth at p2 condition reach optimum due to good performance of its metabolic activity and enzymatic hydrolysis process (kusumaningrum et al., 2012) . the increase of nfe implied by the decrease of crude �ber on p2 by 5.68%. the decrease on crude �ber was triggered by cellulase enzyme produced by microbes and was able to break down cellulose into glucose which then use as carbon and energy resource (sitohang et al., 2012) . the nfe decreased in 60-70% moisture content of fermented rations evidence that watery substrate reduces the microbial activity. microbial activity to produce enzyme was hampered hence degradation of complex compounds cannot optimally conducted. fiber degradation is one of process being hampered process which reduce the yield of nfe. the total microbe also is not correlates to moisture content treatment as in p4. the number of microbe was calculated as highest i.e. 7.43x1010 cfu g−1. high number of microbes does not e�ective proportionally in degrading complex compounds (julendra et al., 2012) . generally, low nfe does not give advantage for the microbe because it is also means organic matter digestible component is low and reduce the amount of energy obtained. nfe is a�ected by moisture content, ash content, crude protein, crude lipid and crude �ber (saad et al., 2016) . 4. conclusions fermentation of local raw materials rations in 50% moisture content can increase total microbes, total acidity, crude protein, dried matter, organic matter and nitrogen-free extract. the process in contrary decreases crude lipid, crude �ber and ph. 5. acknowledgment author would humbly thank you to the directorate general of higher education for providing research grant through competitive scheme 2015. thank you also be delivered to students involve in this 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718–726 wajizah, s., samadi, u. y, and m. e (2015). evaluasi nilai nutrisi dan kecernaan in-vitro pelepah sawit (oil palm fronds) yang difermentasi menggunakan aspergillus niger dengan penambahan sumber karbohidrat yang berbeda. agripet, 15(1); 13–19 © 2019 the authors. page 53 of 53 introduction experimental section materials preparation and formulating rations moisture content determination and the process of fermentation research method and data analysis variable observed results and discussion conclusions acknowledgment title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper feasibility of local commodities on peatlands resti salmayenti1*, muhammad sugihartono2, elham sumarga3, fauziah nur1, aan aryanti sandra2 1department of geophysics and meteorology, faculty of mathematics and natural resources, institut pertanian bogor, bogor, 16680, indonesia 2aquaculture study program, faculty of agriculture, universitas batanghari, jambi, 36122, indonesia 3school of life sciences and technology, institut teknologi bandung, bandung, 40132, indonesia *corresponding author e-mail: salmayentiresti@gmail.com abstract indonesian peat ecosystem, generally managed for protection and cultivation functions, contributes to providing economic benefits to the local community through agricultural practices. this study aims to evaluate the feasibility of local commodity agriculture (coffee, areca, coconut, and pineapple) on peatland from social, ecological, and economic perspectives using descriptive and quantitative approaches in mendahara-batanghari, jambi. data was collected from interviews of 60 farmers in two villages with three types of farms, including monoculture and polyculture of commodities. the results of this study showed that socially, farmers still have difficulty with access and infrastructures. coconut, areca, and coffee are popular among the smallholders because of land suitability, low maintenance, and high selling price. from an ecological perspective, intercropping on polyculture farms is able to store more carbon with a high density of biomass than on monoculture farms. generally, the carbon emissions of local commodity farms are lower than other types of plantations, such as oil palm and rubber plantations. lastly, from an economic perspective, local commodity farming in the study area is feasible based on analyses of net present value, benefit cost ratio, and internal rate of return. polyculture farms provide higher benefits compared to monoculture land. the income is considered sufficient for standard living needs, and there is potential to increase the revenue by developing and optimising processing product industries. keywords economy feasibility, local commodity, peatland, restorations received: 15 march 2022, accepted: 7 june 2022 https://doi.org/10.26554/ijems.2022.6.2.67-75 1. introduction indonesia peatlands provide multiple types of important ecosystem services such as carbon storage, water regulation, biodiversity, ecotourism and other cultural services which are valuable for local communities. in case of supporting regional economy, peatland is widely used for agricultural purposes. however, most activities related to land cover changes of peat forests led to a decrease in ecosystem quality. peat oxidation, biologically, emits around 4.5 tc/ha/yr from burnt peatland and about 7.9 tc/ha/yr from drainage (hirano et al., 2014). moreover, drained peatland generates continuous carbon emissions through an oxidation process and affects the lowering groundwater level, implicating land subsidence. peat fires also produce harmful smoke for health and regularly restrain social and economic activities. hansson and dargusch (2018) estimated that 2-million ha peat restoration would cost us$4.6 billion. the commodities cultivated on peatland vary, and some could lead to ecosystem degradation. besides economic benefits from agriculture practices, the effects on the environment and social perspective are also essential to be considered. some agricultural commodities are considered suitable for the peat ecosystem, known as the paludiculture system, which includes the cultivation of fish and livestock on peatlands known as silvofishery and silvopasture (tata and susmianto, 2019). this system is introduced in order to support the development of the local economy along with maintaining the ecological function of peatlands. local commodities are able to grow on degraded land or shallow peat areas without drainage. according to uda et al. (2020) some local commodities can promote sustainable agricultural activities which have positive values in sustainability, profitability, and scalability aspects, especially sago, banana, and pineapple, followed by kangkong, tengkawang, dragon fruit, mangosteen, and melon. yanarita et al. (2020) also recommended sago as an alternative for forest restoration economically and socially. the economic, social, and environmental contributions of developing local commodities on peatland are essential to https://doi.org/10.26554/ijems.2022.6.2.67-75 salmayenti et. al. indonesian journal of environmental management and sustainability, 6 (2022) 67-75 analyze (gunawan and afriyanti, 2019). according to bagio et al. (2021) low social awareness (knowledge) on peatland management contributed to drought, potentially leading to economic loss. many local communities utilize peatland for agricultural purposes in tanjung jabung timur district, jambi. they cultivate local commodities such as coconut, areca, coffee, and pineapple. budiman et al. (2020) stated that local commodities help restore the peat ecosystem. this study intends to identify the feasibility of local commodities business on peatland. this aims to initially understand the agricultural practices in the study area from sustainable perspectives, i.e. from social, environmental, and economical perspectives. two villages in the peat hydrological unit (phu) of mendahara-batanghari, jambi, indonesia, were selected as study areas. 2. experimental section 2.1 study area this study was conducted in two villages, mendahara tengah and merbau. those regions are part of the mendaharabatanghari phu located in sub district mendahara, district of tanjung jabung timur, jambi province (figure 1). there are several local commodities cultivated by the farmers. this study examined both monoculture and polyculture farming systems of the most popular commodities, including coconut, areca, coffee, and pineapple, by smallholders. this study differentiated the commodities into three groups of farming composition: a monoculture land of pineapple and two polyculture land, coconut areca and coconut areca coffee. detailed information regarding the area, commodities, and farming system of each study case can be seen in table 1. interviews were conducted in both villages with three groups of farmers. 2.2 methods 2.2.1 social acceptance this indicator represents the social preferences of agriculture activity of local commodities. this indicator was elaborated using a descriptive-qualitative analysis based on interviews with the farmers and related stakeholders on the following parameters: a) access and infrastructure facilities; b) agricultural preferences; c) the influence and interests of stakeholders; and d) perceptions and acceptance of sustainable agricultural practices. 2.2.2 environmental impact this indicator explains the potential environmental impacts of local commodities farming on peatland. the analysis focused on particular aspects including the condition of existing agricultural land, carbon storage, carbon emission, and fertilizer use. the information was collected through interviews with farmers and literature reviews. figure 1. area of case study of feasibility assessment of local commodities in mendahara-batanghari, jambi (badan restorasi gambut, 2020) 2.2.3 financial feasibility the farming activities are conducted to support the welfare of farmers. in order to analyze the profitability of the farming, this study a) estimated the economic feasibility using npv, bcr, and irr approaches using the equation 1, 2, 3; b) calculated the annual incomes and expenditures comparison; c) analyze the stability of market and price; and d) analysed the potential of added value applied by society in the study area based on equation 4. npv = n∑ t=0 bt − ct (1 + i)t (1) note: npv = net present value, bt = benefits in t year, ct = costs in t year, i = interest rate, t = farming year. net b c = ∑ p.v.net benefit(+)∑ p.v.net benefit(−) (2) note: net bc = benefit and costs ratio, net benefit (+) = total benefits in profitable year, net benefit (+) = total benefit in non-profitable year. irr = [ i′ + npv′ npv′ − npv′′ (i′′ − i′) ] (3) note: irrc = internal rate of return, npv’ = npv at the interest rate i’, i’ = interest rates that produce positive © 2022 the authors. page 68 of 75 salmayenti et. al. indonesian journal of environmental management and sustainability, 6 (2022) 67-75 table 1. agricultural practices of case study in khg mendahara-batanghari, jambi case study village mendahara tengah merbau area (km2)* 67.3 87.5 inhabitant (in 2018)* 3,926 2,852 commodities coconut areca coffee coconut areca, pineapple cropping system polyculture: coconut (120-160/ha), polyculture (coconut-areca): coconut areca (1,000-1,300/ha), (140-160/ha), and areca (1,200-1,600/ha), and coffee: (1,100-1,300/ha) monoculture (pineapple) (36,000-51,000/ha) (badan pusat statistika, 2019) npv, npv” = npv at the interest rate i”, i” = interest rates that produce negative npv. i = b c (4) note: i = average income during the farming year (idr/ha/year), b = average annual benefit (idr/ha/year), c = average annual costs (idr/ha/year). 3. results and discussion 3.1 social acceptance 3.1.1 access and infrastructure facilities mendahara tengah and merbau villages are only accessible by boat and motorcycle. the distance from the capital city of jambi province to mendahara tengah and merbau is approximately 113 and 80 kilometers, respectively. the distance between the agricultural land and settlement area in mendahara tengah is within a kilometer radius, and in merbau is within 1-5 km, even more than 5 km for most coconut areca farmers (65% of respondents). farmers agreed that the general condition of the infrastructures in their villages is considerably poor (table 2). the roads connecting the villages to the capital city of district are not well constructed. moreover, there is no paved roadway within the villages. during the wet season, the road made of clay and grass becomes slippery, making transportation limited. motorcycles that the farmers commonly use to reach the buyers are hardly operated during the rainy days. in contrast, during the dry season, the obstacle is encountered by the buyers who transport the product to the main road using boats. these situations become a burden for farmers due to the higher expense needed for transportation. the communication infrastructure is also hardly found in the villages. internet access is limited in the area close to the river. therefore, the farmers often complain that there is a lack of information regarding the market condition. 3.1.2 agricultural preferences the number of residents who farm coconut, areca, and coffee has increased in the last decades due to the popularity of the commodities (table 3). this is supported by the higher prices of the products compared to the prices of others. the farmers also favour these commodities because of the lower maintenance costs and even zero fertilizer costs. they only use herbicide to clear the weeds. the main difficulties are the high production costs (additional labour cost for extensive land) and the transportation costs, usually higher during the wet season. for monoculture farming of pineapple, the farmers received the nurseries from governmental aid. there is no extra cost for fertilizers and pesticides (organic). however, the maintenance of pineapple land is considerably hard. because the gap between the plant lane is quite close and the plant is relatively small, farmers cannot use herbicide and have to clear the land manually. there are also pests and wild pigs that often eat the plants. moreover, the price of pineapple is lower than othes. some farmers are willing to shift their pineapple farm to coffee and areca. 3.1.3 the influence and interests of stakeholders agricultural development in the study area involves several stakeholders, i.e., farmers, farmer groups, buyers (customers and collectors), local and central governments, and ngos (table 4). farmers have been cultivating local commodities as their main livelihood for decades. there are farmer groups in each village. farmers use the organization as a forum for discussions about agriculture. however, the continuity of farming depends strongly on the influence of collectors (toke). toke is the primary buyer for the harvested products. toke usually give loan to the farmers by taking the potential yields that will be harvested shortly. this purchasing system has been established for decades, and it seems unchangeable. in recent years, other parties, including local government, governmental peat restoration agency (brg), and an ngo (warsi), have run several programs related to the development of sustainable agriculture on peatlands. all parties are interested in introducing more sustainable practices of agriculture on peatlands. the local government has been supplying nurseries of pineapples and supporting entrepreneurship for farmers. brg and warsi also provide support in the form of giving processing equipment to add product values, conducting studies and training, and providing assistance to enhance the skills of farmers and © 2022 the authors. page 69 of 75 salmayenti et. al. indonesian journal of environmental management and sustainability, 6 (2022) 67-75 table 2. satisfying level of supporting infrastructure conditions in the study area mendahara-batanghari response supporting infrastructures roads transportation communication strongly dissatisfied 0% 0% 0% somewhat dissatisfied 79% 95% 100% somewhat satisfied 21% 5% 0% strongly satisfied 0% 0% 0% table 3. constraints and predominant factors of local commodity cultivation according to smallholders the study area mendahara-batanghari indicator coconut areca coffee coconut areca pineapple constraints high cost (100%) high cost (90%) high maintenance (100%) transportation (100%) transportation (100%) low price (100%) benefits low maintenance (100%) low maintenance (85%) low cost (100%) land suitability (100%) land suitability (100%) land suitability (100%) popularity among farmers (100%) popularity among farmers (100%) other residents. 3.1.4 perceptions and acceptance toward local commodity development generally, the farmers have agreed that they have contributed to peatland preservation for several reasons. first, the farmers actively expand the cultivation of local commodities. the governments support the development of areca, coffee, and pineapple farming because they require relatively low drainage levels. secondly, for years, the farmers have started developing awareness about the damages of land fires. in the past, burning was the best, cheapest and fastest procedure to clear the land. they were convinced that the produced ash enhances the fertility of their land. currently, locals join the government in preventing forest and land fires. the impact of forest fires in 2015 brought trauma for them. fires have spread and damaged their agricultural land. in addition, the smoke affected their health, resulting in a higher number of acute respiratory infections (ari) cases, particularly among children patients. however, awareness of residents to protect peat ecosystems is still limited. other essential ecosystem functions of peatlands, such as water and climate regulations and biodiversity protection, are less taken into account. this might be due to a lack of understanding among locals. the respondents mentioned that few have participated in training (15% of coconut-areca farmers). interviewed farmers in the studied areas are primarily elementary, and junior high school graduates; only 5% of them (coconut-areca farmers) hold a university degree. 3.2 environmental impact 3.2.1 land and drainage most agricultural land owned by the respondents was converted from the forest. the rest was already cultivated hereditary. the land was converted in several ways in the past, including by manual clearing, forest firing, and indirect firing called peat peeling. peat peeling is a land clearing procedure that takes out the upper layer of peat (around 20 cm) to be burned in another place blocked by canals to prevent widespread fire. however, the use of fire in land preparation still potentially increases the risk of forest and peat fires. in general, indonesian forest and peat fires can be strongly linked to human activities (medrilzam et al., 2014; sumarga, 2017). after clearing, the land area requires canals and ditches (smaller ones) for drainage (table 5). the canals are constructed in the agricultural land by the farmers voluntarily. the width of the canal is approximately 50-100 cm. most canals are blocked during tide periods to prevent flooding and are opened during the dry season. according to the farmers, the land is becoming drier as an impact of canal construction. 3.2.2 carbon emissions drainage on peatlands reduces the level of groundwater which leads to greenhouse gas production. drained peatlands decrease the soil capacity to retain water and accelerate the peat decomposition rate (agus and subiksa, 2008). hence, the lower the groundwater level, the higher the carbon emissions. table 6 presents the average groundwater level and the estimated carbon emissions from agriculture on peatlands. for comparison, the information of other peatland uses (plantation (sago, oil palm, rubber), primary forests and secondary forests) are also provided. the emis© 2022 the authors. page 70 of 75 salmayenti et. al. indonesian journal of environmental management and sustainability, 6 (2022) 67-75 table 4. stakeholders analysis in terms of the development of local commodity cultivation in study area khg mendahara-batanghari stakeholder power main interest smallholders cultivating on their (peat) land increasing their welfare community of farmers conducting meeting and discussions sharing and implementing knowledge business activity toke (buyers) purchasing agricultural products making profit giving loan market monopolism consumers purchasing agricultural products consumption village government arranging regulation regarding preserving peat ecosystem peatland uses at village level regional government sharing information and knowledge regional economic development supplying aids human resources development preserving peat ecosystem ngo and national institution sharing information and knowledge regional economic development providing consultation and assistance human resources development supplying aids preserving peat ecosystem table 5. the use of canals in local commodity plantations in study area mendahara-batanghari criteria coconut areca coffee coconut areca pineapple have no canal 0% 0% 0% have canals 100% 100% 100% sions from local commodity farming on peatlands are around 17-39 tco2/ha/yr. this number is higher than emissions from sago plantation, primary and secondary forests, but lower than emissions from the well-known plantation, such as oil palm and rubber which could reach 178 tco2/ha/yr. it is noted that among the local commodities, the groundwater level for coconut and coffee farms is relatively high, reaching 57 cm. the water level on peatlands needs to be kept below 40–50 cm to slow down land subsidence (noor, 2001). 3.2.3 carbon storage the conversion of peat forest to agricultural land implicates the change in carbon storage. the variability of carbon stored as dry matter biomass (dmt) above land in various land covers is displayed in table 7. it shows that the carbon stored on a monoculture farm is lower than the one on peat forests due to less biomass and vegetation density. however, an agroforestry system that cultivates several commodities increase the capacity of carbon stored. the intercropping system of polyculture increases the density of vegetation and the capability of carbon absorption. coffee is a commodity which is recommended for agroforestry/intercropping system. based on saidi and suryani (2021) around 54% of peatlands in tanjung jabung timur are marginal suitable for coffee plantations. 3.2.4 the use of fertilizers exaggeration use of fertilizers on agricultural land would bring negative effects to the ecosystem. according to a study by landry and rochefort (2012) the fertilizers for agriculture on peatland are only required on drained poor land. based on surveys and interviews in this study, most farmers hardly fertilize the land. there are only some minor cases when fertilizers are needed on considered-poor land. as a result, the farming of local commodities in the study area is considered organic. 3.3 economic feasibility 3.3.1 financial analysis the costs of smallholders in cultivating commodities vary in different regions enormously depending on the social and economic conditions. farming costs carried out by the smallholders in the study area consist of costs for land preparation, equipment, nurseries, herbicides, planting, harvesting, and transportation. meanwhile, costs of land, labor, and infrastructure (canals) are not taken into account because they are voluntary works. the polyculture system has a planting interval between commodities. generally, coconut is the first commodity to be planted, followed by areca after 4-7 years, and coffee in the next 4 years. coconut commodities are able to be harvested after 6-8 years, while areca and coffee are harvested after 3-4 years and pineapple after 18 months. the results of financial analysis of local commodity farm© 2022 the authors. page 71 of 75 salmayenti et. al. indonesian journal of environmental management and sustainability, 6 (2022) 67-75 table 6. estimation of carbon emissions based on water levels in various peatland covers commodity average estimated carbon emission groundwater level (m) (tco2/ha/year)* sago -0.09 to -0.73a 6 to 60 coconut, coffee -0.3 to -0.5c 21 to 34 areca -0.25 to -0.57g 17 to 39 pineapple -0.3 to -0.4d 21 to 27 oil palm -0.5 to -0.8c,f 45 to 73 rubber -0.83 to -1.96e 75 to 178 primary swamp forest -0.13 to +0.1b 0 to 3 secondary swamp forest -0.3 to -0.56f 3 to 7 source: a. (watanabe et al., 2009); b. (hergoualc’h and verchot, 2012); c. (agus and subiksa, 2008); d. (situmorang et al., 2019); e. (wakhid and nurzakiah, 2021); f. (adhi et al., 2020); g. (andesmora, 2021); *estimated based on hooijer et al. (2010) with assumption of drained area: 25% for swamp forest, 75% sago, coconut, coffee, pineapple, and 100% for oil palm and rubber plantations. table 7. estimation of carbon storage based on land cover types on peatlands commodity carbon storage (dm ton c/ha) sago 53a coconut 51b coffee 82 (shade), 52 (sun)c 62-79h agroforestry land 144d oil palm 2-60e rubber 32-67f primary swamp forest 157g secondary swamp forest 140g sources: a. (tata and susmianto, 2019); b. (bhagya and maheswarappa, 2017); c. (van noordwijk et al., 2002); d. (novita et al., 2021); e. (kho and jepsen, 2015); f. (corpuz and abas, 2014); g. (krisnawati, 2014); h. (yunianti et al., 2021). ing in the study area are presented in table 8. all of the local commodity farming has a positive npv, which shows that these activities are financially feasible. three types of farming are also categorized as feasible from the estimated bcr and irr values. the irr of the three types of farm is greater than the discount rate (12%), with a bcr of more than one. therefore, it can be concluded that the development of local commodities, both monoculture pineapple and coconut-areca and coconut areca coffee (polyculture) farming, can be a financially feasible option for smallholders. 3.3.2 incomes and expenditures comparison the farming area owned by farmers varied from 1 ha to 13 ha. the agricultural activities are carried out by themselves or with families. meanwhile, the pineapple farmers use a landsharing system where a group of farmers, namely sumber usaha, co-cultivates the land owned by four members. the average area of pineapple farms is 1.6 ha per farmer, smaller than the area of the other commodities. table 9 displays the information on income contribution from agricultural activities. the polyculture farms provide higher profit than the monoculture (pineapple) farms. if the production of each type of commodity is compared, the two-commodity land of coconut and areca provide the highest production. after all, the three-commodity farms provide higher income because of higher harvesting frequency and less production cost. additional labor costs for areca peeler apply in merbau, while there is no cost in mendahara tengah. the farmers or their family members carry out the peeling process in this village. the income from one-hectare polyculture land surpasses the monthly minimum needs per person (ump) in jambi. meanwhile, sharing profit system from pineapple farms only contributes to less than half of ump jambi. the sufficiency level of the income depends on the total area owned by each farmer, the number of family members, personal lifestyles, and other sources of income. this study found that all respondents agreed that their income from agricultural activities fulfilled their basic needs, even excessed according to the farmers with extensive land (>10 ha). © 2022 the authors. page 72 of 75 salmayenti et. al. indonesian journal of environmental management and sustainability, 6 (2022) 67-75 table 8. financial analysis of local commodity farming in the study area mendahara-batanghari indicators coconut areca coffee coconut areca pineapple total costs (million idr) 513 1.786 137 total revenue (million idr) 3.16 3.758 375 net benefit (million idr) 2.804 1.972 237 npv (million idr) 447 333 68 irr (%) 45.95 45.92 218.60 bcr 17.05 22.49 7.65 note: estimated for one-hectare land with a discount rate of 12% and a 25-year planting period. table 9. financial conditions of smallholders in the study area mendahara-batanghari criteria unit a b c land ownership proprietary % 100 100 100 labour family member % 100 100 group of farmers % 100 agricultural land min-max ha/farmer 2-7 1-13 1-4 average ha/farmer 3.9 4.5 1.6 basic needs family member people 2-4 2-5 1-5 monthly needs* million idr/family/month 5.3-10.6 5.3-13.2 2.6-13.2 average income million idr/month/ha 9.3 6.5 0.96 adequacy level excessed % 10 sufficient % 100 90 100 (standard living) less sufficient % insufficient % note: a) coconut areca coffee; b) coconut areca; c) pineapple; *based on provincial standard minimum wage (ump) jambi 2020 (badan pusat statistika, 2020). table 10. market condition of local commodity business the study area mendahara-batanghari criteria coconut areca coconut pineapplecoffee areca nursery purchasing strongly easy 100% somewhat easy 100% 90% somewhat difficult 10% strongly difficult 100% product selling strongly easy somewhat easy 70% 15% 100% somewhat difficult 30% 85% strongly difficult price strongly stable somewhat stable 100% 100% 100% somewhat fluctuate strongly fluctuate sales toke 100% 100% market 100% 3.3.3 stability of market and price the market condition in the study area is presented in table 10. most farmers expressed that it is convenient to purchase the nursery. the sales process was also quite simple. coconut, areca, and coffee are sold to toke, which offers a selling guarantee. the challenge is found in the transportation process, which is costlier during wet seasons. looking at the price, it tends to be stable because toke monopolies the © 2022 the authors. page 73 of 75 salmayenti et. al. indonesian journal of environmental management and sustainability, 6 (2022) 67-75 table 11. general condition of the processed-product business in the study area, mendahara-batanghari type of business business scale average productivity market price (idr/kg) coffee processing medium enterprise 6 ton/year 150,000-250,000 pineapple dodol home industry 480-600 kg/year 40,000 market. the farmers of coconut, areca, and coffee concluded that they are satisfied with their commodity preference, and there is no planning on changing the commodity in the near future. on the other hand, most pineapple farms are willing to change their commodity to more profitable ones, such as areca or coffee. 3.3.4 potential of added value most harvested products from the study area are sold to toke without post-harvest processing. only a tiny part of coffee and pineapple is processed into roasted coffee and pineapple dodol (traditional food) by locals to add higher product value. the dodol home-processing industry is carried out by the ketupat farmer group in collaboration with bumdes (village-owned enterprises) in merbau. the industry is able to produce 40-50 kg of dodol at once (table 11). with the price at idr 40,000/kg, the net profit can reach 30% of total revenue or about idr 600,000 on average. however, production is occasionally carried out because it depends on demand. marketing is still underdeveloped, and the market is limited due to management and permit issues. the sustainable peat farmers group developed a coffee processing industry in a neighboring village. their products have been recognized with the brand peatland coffee liberika mendahara. the product has already reached the online market with a price range of idr 150,000-250,000/kg, depending on the quality. in addition, farmers in merbau also carry out a post-harvest drying process for areca. there is a place to store unsold peeled areca called ’areca house’. drying the areca increases the price to idr 19,000/kg instead selling it in logs at idr 120,000-150,000/sack or as peeled areca at idr 5,000-9,000/kg. 4. conclusions socially, the local commodities cultivated in the study areas are favored by the stallholders despite the limitation in access and infrastructures and price differences between commodities. all studied farming types are feasible options from an economic perspective, and they generate incomes that are sufficient for basic living costs, from the polyculture farming system in particular. this study is an initial analysis of peat friendly local commodity-based business development. in order to improve the local economy, further research is required, including to assess and implementation strategies in facilities and infrastructure development, application of related sustainable agricultural practices, the development of multiple income based strategy through the application of post harvest technology, processed agro industries, and agro silvofishery, as well as the development of farmer partnerships between villages, local enterprises, and partnerships with the private sector. 5. acknowledgment this research was supported by peat restoration agency of indonesia (brg). we thank our colleagues from deputy for research and development of brg who provided insight and expertise that greatly assisted the research. we would also like to show our gratitude to the reviewers for their comments during the development of research proposal and results, as well as the farmers and 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facilities agricultural preferences the influence and interests of stakeholders perceptions and acceptance toward local commodity development environmental impact land and drainage carbon emissions carbon storage the use of fertilizers economic feasibility financial analysis incomes and expenditures comparison stability of market and price potential of added value conclusions acknowledgment title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper assessment of fire hazard on the readymade garment industry in chittagong city, bangladesh: a geospatial analysis of cepz and baizid industrial hub shahidul islam1*, rafion islam roman1, 1department of geography and environmental studies, university of chittagong, chittagong-4331, bangladesh *corresponding author e-mail: shahid ges@yahoo.com abstract the readymade garments (rmg) industries are the largest contributor for the national export earnings and second largest contributor in gross domestic product (gdp) of bangladesh. starting from the late 1970s, rmg sector of the country has dramatically grown up a geometric progression over the few decades which were started as a minor as well as non-traditional sector with a negligible of exporting. although the country has a glorious history of textile, cloths and clothing’s from the ancient period of time. over the preceding decade, fire and fire hazard is the continual problem in the readymade garments industries of bangladesh. considering this as a crucial problem, this paper was carried out a geospatial assessment of fire hazard effects on readymade garment industries in chittagong export processing zone and baizid industrial hub of chittagong city, bangladesh. the study was mainly carried out based on primary field survey while secondary sources were also used in comparing and basement of analysis. there were two types of parameters (hard and soft parameters) generally have used to assess the fire hazard risk and vulnerability on readymade garments. based on 19 soft parameters in the study, a suitable and appropriate fire risk index (fri) was developed to identify the risk and vulnerability of the industry. in both of the study area, there were 50 garment industries were surveyed where each area covered by 25 sample stations. by the evaluation of soft parameters, the study assessed that the chittagong export processing zone has a mean safety is 90.45% (9.55% deviation from the standard) and 80.29% safety (19.71% deviation from the standard) covered in baizid industrial hub. although both of them were considered as good condition as well second one nearest to the average. electric short circuit was the prime cause of fire in cepz and baizid industrial hub. overall, it was found that about 80% garments in baizid industrial area under in good condition which is (10-20) % deviation from ideal case. while cepz area about 80% garments was categorized as excellent condition, it is only 8% seen in baizid area. the study also reveals that there is no garment in both areas which is in poor as well as extremely vulnerable to fire hazards. keywords readymade garments, fire hazards, quantitative and qualitative measurements, vulnerability and risk indexing, fire safety parameters received: 09 december 2018, accepted: 28 february 2019 https://doi.org/10.26554/ijems.2019.3.1.20-28 1. introduction readymade garment is the principle exporting sector in bangladesh, approximately 78% of the total foreign currency generated from this sector and also the second largest apparel exporter in the world with a total export of usd $17.91 billion in the fiscal year of 2010-11 (bgmea, 2016). the garment sector has enjoyed a significant growth in bangladesh for the last three decades. from a humble beginning of 12 enterprises in 1978, this sector currently consists of 4,500 factories of various sizes, although around 3,500 are currently operating (abdin, 2008). almost all of these factories are distributed primarily in the two of the largest cities dhaka, the capital and chittagong, the port city. unfortunately, given the labor intensive nature of the industry, the density of workers on factory floors is very high. this high density of workers results in a large number of injuries and fatalities in the event of an accident (habib, 2009; abdullah, 2005) the readymade garment industry is a highly competitive industry and cost-saving is highly valued sector in the economic development of bangladesh. while the lack of a safety culture, cost-cutting measures often affect the health and safety of the workers (abdullah, 2005). clothing is easily flammable and as such fire is one of the most frequent and damage inducing accidents in these factories in bangladesh (ahmed, 2007). fire is also purported to be https://doi.org/10.26554/ijems.2019.3.1.20-28 islam et. al. indonesian journal of environmental management and sustainability, 3 (2019) 20-28 the largest cause of on the job injuries and fatalities in this sector. each and every new incident of fire and related damage adversely affects the reputation of the industry abroad, especially since the working conditions in the manufacturing sector in the developing countries is a general cause of concern in many developed countries (akhter, 2010). given the importance of fire safety in the garment sector, there have been concerted efforts from the government, the industry lobby (bangladesh garments manufacturers and exporters associations, bgmea) and the international buyers of the apparel products, to improve the fire safety culture and this has indeed reduced the fire incidents and losses significantly (alam, 2006; j and t, 2009). despite the various measures, rules and regulations implemented in the past decades, there are still several instances of fire outbreak in the garment factories every year, resulting in significant losses of lives, livelihoods (through injuries), equipments and materials (j and t, 2009). as is common in any developing country, there is a lack of data on fire safety in bangladesh, and, although there is a few studies on fire safety status in general no comprehensive fire safety assessment of the garment factories were undertaken before. in the wake of a recent fire disaster at a garment factory that killed more than 100 factory workers fire safety evaluation of the industry became even more important (firoz, 2011). the recent fire at the tazreen fashions garment factory has brought the perennial challenge of worker safety into the spotlight once again. given the constant pressure to lower costs and the dearth of meaningful government oversight, businesses are continually tempted to reduce costs at the price of worker safety. worker deaths are not new in bangladesh especially chittagong city, and while they have led to recriminations and some important changes, fires and other tragic accidents continue. fires have been a persistent problem in readymade garment (rmg) industry for over a decade in chittagong city industrial areas. the country’s comparative advantage is low costs; the minimum wage for workers is a mere tk. 3,000 ($37) per month (fy and n, 2011). as keeping costs low has been one of the keys to the sector’s success in bangladesh, there are strong disincentives to make necessary investments in worker safety. while improvements were made over the years, the safety record of the chittagong city industrial areas rmg industry remains poor (tazreen and sabet, 2013). there is some disagreement about the number of worker deaths in the industry. according to the bangladesh institute of labour studies, 431 workers died in 14 major fire incidents between 1990 and 2012 (prothom, 2013). however, according to bangladesh fire department, 414 garment workers were killed in 213 factory fires between 2006 and 2009 alone (prothom, 2013). especially, enforcement of the rules and regulations and day-to-day health and safety management practices on factory floor is a major issue. in order to improve the fire safety in the readymade garment industries, it is important to understand and quantify the current state of affair in fire safety of the garments factories. therefore the aim of this study is to examine the fire hazard in rmg industrial sectors and intensity of fire hazard, existing conditions and remedial measures to reduce the problems in epz and nonepz industrial hub of chittagong city. to investigate the existing fire safety deign of the readymade garments industries of chittagong city, this study has tried to assess the risk and vulnerability due to fire hazard in rmg industries at the study areas, was prepared a vulnerable map based on severity and magnitude of rmg industries in both area and finally was explored the fire risk index and the causes and consequences of fire hazard. 2. experimental section 2.1 study area the study area, the chittagong city of bangladesh (figure 1) is the principal city of the south-eastern region of bangladesh and the second largest city of the country after capital dhaka. the city is also the principle commercial hub of the country as the largest sea port is located here. the study is mainly carried on two principle industrial locations at biazid industrial hub and chittagong export processing zone (cepz) areas. the biazid industrial hub is the northern part of the city is located at 22022’n to 22028’n and 91046’e to 91051’e with three city corporation ward. while the chittagong export processing zone (cepz) is the southernmost part of the city located at south halishahar is only 3.1 km from the sea port, 5.5 km from the cbd of chittagong city and 11.3 km from the shah amanat int. airport, chittagong (bepza, 2013). 2.2 methods and materials considering the importance of fire safety for the worker in rmg industry at chittagong city, an intensive study was carried out on two important industrial areas at chittagong city (cepz and baizid industrial hub). the study was mainly based on primary field survey. however secondary source of information are also used for making background of the study. 2.2.1 primary field survey primary field survey has been conducted under the present study during the month of january to march, 2016. the primary field survey included a questionnaire survey on various levels of the industries, mapping, and observation and in depth interview from fire related person and worker. questionnaire survey : to conduct the research, some questionnaires have constructed with the open and closed type of questions along with pre-coded and coded manner. the questionnaires were developed on the basis of the objectives to determine the fire safety system for readymade garments industry in chittagong city. fire hazard estimation is mainly carried out from the garments worker, fire safety officers and garment’s security officers etc. and at © 2019 the authors. page 21 of 28 islam et. al. indonesian journal of environmental management and sustainability, 3 (2019) 20-28 figure 1. location of the study area in bangladesh (source: chittagong city corporation, chittagong development authority and a modification of arc gis 10.2) the same time also some opinions and valuable suggestions have been taken from bgmea, rmg, bnbc, and fscd officials. sampling : a purposive judgment sampling method has been used for the study. in cepz area, there about 167 industries where 72 are garments and garments related industry. due to authority restriction and other jurisdictional limitations, only 25 garment industries in cepz have taken as a sample for the study (38% of the total). therefore, for a balance of comparison at biazid industrial hub also taken 25 industries as a sample for the survey. mapping: arc gis 10.2, illustrator, photoshop etc. software have used for the purposes of mapping and analysis of the risk and vulnerability assessment at the readymade garments in both areas. for the base of accuracy, source maps have collected from the bangladesh export processing zone authority (bepza), bgmea, chittagong development authority (cda), chittagong city corporation (ccc) and google satellite. checklist survey : a checklist has developed and surveyed on the basis of bangladesh fire service and civil defense authority (bfscda) for certifying a garment factory’s existing fire safety system and capacity. in depth interviews : some detail in-depth interviews have conducted with garments workers, fire safety officers and fire safety workers who are experienced and available knowledge about fire and fire safety systems in his working place. 2.2.2 secondary data collections and analysis a detail and study related secondary data and information have been collected from the various organizations like chittagong city corporation (ccc), chittagong development authority (cda), bangladesh fire service and civil department (fscd), bgmea, bepza etc. some information also have been collected from banglapedia, wikipedia, journals, newspapers, archives, research papers and web sites of different organizations. 2.2.3 data presentation and analysis collected primary surveyed and secondary sources data have analyzed and represented through spss 10.0, ms excel, ms access and arc gis 10.2 etc. following two type of assessment methods have been applied for risk and vulnerability identification: qualitative method for fire risk assessment : in this study, a qualitative method by checklists and narratives approach has been applied on the basis of hultquist and karlsson (2000) (table 1) [14]. the checklist approach mainly was checked the performance of the building (or, in present case, the garment factory), generally in a yes/no format, with respect to a set list of standards or codes relevant to fire safety according to following parameters with their weights. quantitative method for fire risk index (fri) of assessment: in quantitative method, risk indexing has been used as evaluating multiple attributes into a single value and various risk indexes by primarily in the number. types of parameters (attributes) considered and the arithmetic functions used to summarize these parameters. among various types of fire risk rating, the most popular ones are gretener’s index, frame index, dow’s fire and explosion index, fire system evaluation system (fses) index and hierarchical approach (hultquist and karlsson, 2000). the study mainly carried out through dow’s fire and explosion index by following equation: fri = ∑n i=1 xi∑n i=1 wi x100 (1) where, fri = fire risk index in percentage, xi is a dimensionless grade parameter of i; wi is the importance of parameter i; and i is number of parameter as i= 1, 2,..n, n=19. the weight wi was used to incorporate the variations in importance of the parameters relative to each other and is generally determined by expert opinion and/or from previous data. the grade points or scores xi have reflected the ’measure’ of the danger, consequences or safety offered by a particular parameter i. since the units of measurement for different parameters were different, xi was expressed as a normalized dimensionless number watts (1997). © 2019 the authors. page 22 of 28 islam et. al. indonesian journal of environmental management and sustainability, 3 (2019) 20-28 table 1. list of different parameters with their level of weight and consequences (source: watts and hall, 2002) parameters weight of parameter consequence and descriptions width of the main road 5 most important: distance between two building 5 if not present, general stair 5 very high damage of both life exit door locked 5 and properties may occur emergency exit in the factory 5 water reservoirs 5 fire fighting pump 5 fire drilling held 4 important: emergency gate blocked by furniture 4 if not present, fire extinguished 4 considerable damage of both life combustible material 4 and properties may occur director system 4 distance fire service station 4 is the transformer near the 3 essential: work ability of announcement 3 loss of life may not occur but other losses emergency light 3 and injuries are high first aid box 3 gas mask 2 preferable: electric cable over headed 2 loss of properties and injuries are considerable table 2. description of the grade point of the parameter grade point not quantifiable parameters quantifiable parameters % subjective observations deviation from ideal case 5 excellent less than 10% 4 good from 10%-20% 3 average from 20%-30% 2 poor from 30%-40% 1 very poor more than 50% 3. results and discussion 3.1 existing fire safety deign in the rmg industries fire safety design is a group of equipment and or behaviour designed to both reduce the risk of starting a fire and reduce the risk of injury in the event of a fire (watts, 1997; yunus and yamagata, 2012). the structural design to protect the fire hazard includes the aid in reducing the spread of fire and smoke. a storey or floor is any level or part of a building that has a permanent roof and could be used by people (bnbc, 1993). it is very important for any garments to measure the larger condition and understand the occupant level in any garments factory (muhammad, 2011). the number of floors of a garment has been counted through the observation technique. in cepz area 40% garments consist of six floors, as in baizid industrial area it is only 20% and second highest 32% consist of five floors in cepz area. on the other hand in baizid industrial area the highest 24% garments consist of less than three floors, where as it is not found in cepz area. in this study observation method represent that in cepz area the structure of buildings is beautiful, well-structured, and spacious and well planned. on the other hand in baizid industrial area it is ugly, poor-structured, congested and unplanned. access way shall be provided for accessibility of site to firefighting appliances. snorkel or turntable ladder appliances need to firefighting and rescue in high-rise apartment. to allow access of those appliances 30 feet wide road is required (bangladesh fire service and civil defense, 18th september, 2014) (prothom, 2013). accessibility data has been collected through field survey by observation method. in the study area, above 30 feet wide access road has been found 28 % garments in cepz on the other hand in baizid industrial area it is in only 12%. the highest 64% garments road accessibility has been found above 26-30 feet and only few garment access way found 21-25 feet in chittagong epz area. on the other hand in baizid industrial area the highest 32% garments road access way found above 26-30 feet. it is alarming for baizid area 28% garments road are less than © 2019 the authors. page 23 of 28 islam et. al. indonesian journal of environmental management and sustainability, 3 (2019) 20-28 16 feet, which is so difficult for access fire fighting car. general stair is a most important element of any industrial infrastructure used by industrial personnel and worker for frequent movement (muhammad, 2011). in which infrastructure general stairs are wider and present in sufficient number the worker will exit in a short of time in case of fire hazard or any critical situation. in this study, the highest percentage of general stair in baizid industrial area lies in two stairs and then the number of one general stair is 20% (figure 2). the amount of stair above three is seldom seen in this area. on the other hand in cepz area number of four general stair cases is the maximum in this graph. because the large number of worker worked in this factory and the infrastructures are structurally huge. there are about 14% industries in this area seen up to seven general stairs. the number of general stair case one and two are merely visible in cepz. figure 2. conditions of the general stair at the rmg factories of cepz and baizid industrial hub this is one of the important attributes to understand fire safety condition in any factories by considering fire hazard. an emergency exit in industries is a special exit for emergencies such as a fire; the combined use of regular and special exits allows for faster evacuation, while it also provides an alternatives if the rout to the regular exit is blocked by fire (muhammad, 2011). that is why emergency exit is an important factor for the fire safety condition measure of any garments. in the study, the data has been collected by observation methods. the highest percentage of emergency exit in baizid industrial area lies in one emergency exit point and then the number of three emergency exit points is 16% (figure 3). the amount of emergency exit four+ is seldom seen in this area. on the other hand in cepz area number of four+ emergency exit cases is the maximum in this graph. the number of emergency exit case one and two are merely visible in cepz. but it is alarming for baizid area highest (32%) of factories are setup without emergency stair. so, it can be said that the overall emergency condition in cepz is better than baizid area. the following diagram shows the storage of combustible material in both areas. minimal storage of combustible material (cotton, cloth and chemical) ensures the better condition for industry. as combustible materials are easily flammable and it occurs devastating fire. so, it is very perilous if any fire hazard takes place. in the study it is seen figure 3. emergency exit way in the rmg industries at cepz and baizid industrial hub areas of chittagong city that combustible materials are found in every industry of the study area more or less. in both the area it is seen that the average condition stands as the highest. in cepz area 32% garments industries have been recorded very poor storage of combustible material. on the other hand in baizid area it is almost 12%. fire alarm is a device, such as a siren, used in announcing the outbreak of a fire. this study found out that the garment with and without fire alarm. in the study area it has been found that 100% garments are with fire alarm and it is unseen without fire alarm in both areas. smoke detector and heat detector device detect smoke and heat respectively. in the study area these information which have been collected by the survey no garments found without detector system. each and every factory has more or less detector systems. from the study it is seen that detector systems are highly present in cepz area. from the study it is found, the fire safety system is satisfactory in the garments of chittagong city area. most of the garment’s fire safety system is excellent. accessibility and emergency exits are most important factor to keep safe from fire but maximum factories do not follow the standard level in this aspect. it is also observed that fire extinguisher; detective system and fire alarm system are modern and found in satisfactory level. faire safety system is high in cepz are than baizid area but in baizid area it is also good. the main cause of this variation is that the industries of cepz area build on some solid rules which are provided by bepza, fire service and civil defenses and bgmea. bangladesh export processing zone authority is not only provided the rules for epz but also strictly monitor the activities and notice in this sector. on the other hand, in the industries of baizid area it is absent because of lack of fire inspection officer in baizid fire station. proper fire inspection can reduce the vulnerability of garments considering fire hazard in this area. 3.2 infrastructural deign and opportunities to safety risk indexing is a way of evaluating multiple attributes into a single value and various risk indexes differ primarily in the number and types of parameters (attributes) considered and the arithmetic functions used to summarize these parameters (hultquist and karlsson, 2000; bnbc, 1993; muhammad, 2011; quasem, 2002). in this research, the weight reflects © 2019 the authors. page 24 of 28 islam et. al. indonesian journal of environmental management and sustainability, 3 (2019) 20-28 were the importance of the parameters in terms of potential consequences. this research work contains about 19 parameters (on the basis of dodd and donegan, 1994) and those are divided into four categories respectively most important, important, essential and not essential but preferable. in this research higher grade point, higher percentage or lower deviation from ideal case represents good condition for garment industry. there are about seven parameters which are considered as most important (table 1). from the study findings, only water reservoir and presence of fire fighting pump are in excellent condition at biozid industrial hub. on the other hand in the same industrial area five parameters are in good condition those are more than 10% deviation from the standard. the condition of general stair and emergency exit is not good in those factories. it is more than 40% deviation from ideal case. comparatively at cepz area, it is found that among the seven parameters, exactly five parameters are in excellent condition and the rest two parameters are in good condition. the aforementioned bar diagram in six important parameters at the chittagong export processing zone area four parameters are in excellent condition and the rest two are in good condition. on the other hand in case of baizid industrial area among the six important parameters only two parameters are in excellent condition (emergency gate blocked by furniture and distance from the nearest fire service station) and the rest 4 are in good condition. the parameters which are regarded as essential to assess the fire hazards for the readymade garments in the study area are the presence of transformer, workability of announcement, emergency light and first aid box. it is seen from the above diagram that among the four elements of the essential parameter two parameters namely presence of transformer around the garments and workability of announcement have been found in excellent condition and the rest two are in average condition in the chittagong epz area. and the same condition prevails in the baizid industrial area also. to assess the fire hazards in the garments factory a category has been made named preferable parameter. this parameter contains the presence of gas mask when fire hazard occurs and electric cable over head. among the two parameters in cepz area one is in excellent condition and the rest one named the presence of gas mask is in good condition but very nearest to the average condition. on the other hand in bai area among these two parameters one named electric cable over head is in good condition but the rest one named the presence of gas mask is in very poor condition. 3.3 fire hazard risk indexing by different parameters most important parameters are given the maximum weight 5. in baizid industrial area the average grade point of most important parameters 3.96 in scale of 5. in our grading strategy, a large grade point refers to a safer situation. therefore fire risk index (fri) is in an inverse scale, a higher fire risk index (fri) means less risk. the mean fri for 25 factories is 3.96 in scales of 5, which shows that the fire safety practice are bellow the ideal value of 5. it ensures that in case of most important parameters , average value of 25 factory deviation more than 20% to less than 30% from ideal case. so it is considered as average condition but nearly good condition or vulnerable for fire safety in this area. calculate value of overall fire risk index (fri) for baizid industrial area is 3.52 in scale of 4.00. this is (10-20) % deviation from the ideal case. so, it is considered as good condition or less vulnerable for most important parameter. average fire risk index (fri) for essential parameters in baizid industrial area is 2.41 in scale of 3.00. which is deviated more than 20% to less than 30%, it indicates that essential parameters in this area were average condition. in case of preferable parameters this area is in poor condition having scored 1.44 in scales of 3. it is near about 30% deviation from ideal case, so it is considered as vulnerable. on the other hand, cepz is the well planned zone having more facility and specified boundary for industrial development. there have various types of industries and only rmg industries were taken as consideration. in chittagong epz area the average condition of most important parameters for 25 garment industries are 4.67 (calculation has been given appendix) in scale of 5.00. it is only 5.74% deviation from ideal case, which indicates that cepz area is in excellent condition or very less vulnerable regarding its most important parameters. calculate value of overall fire risk index (fri) for cepz area is 3.52 in scale of 4.00. which indicates that, for important parameters the fire safety situation in this area is excellent, which is only 8.12% deviation from ideal case and considered as very less vulnerable? average value of 25 industries for essential parameters in this area is in good condition with score of 2.55 values in the scale 3. it is 15% deviation from ideal case and considered about less vulnerable. in cepz area the condition of preferable parameters is also good. the average fire risk index value for 25 factories is in 1.8 out of 2. in this area fire drilling held regularly, on the other hand gas mask is in average condition. for the purpose of socio-economic development, poverty alleviation and rapid growth of industrialization, bepza tries to attract the local and foreign investors by setting up the epz and delivering necessary efforts and cooperation to flourish our industrial sector [13, 19]. at present in bangladesh, there are about eight epz, from which chittagong epz is the biggest and most export revenue earning ones. in 2010-11 economic years cepz export 14268.66 million us dollars by exporting. at present 172305 workers are working in this epz [13]. cepz lies in 163 hectors land dividing into 501 plots. in which 167 plots turned into © 2019 the authors. page 25 of 28 islam et. al. indonesian journal of environmental management and sustainability, 3 (2019) 20-28 figure 4. comparative scenario of the condition of a) most important, b) important, c) essential and d) preferable parameters figure 5. overall level of good conditions in all parameters sub-sectors at baizid industrial hub and cepz areas figure 6. overall condition of the grouping of parameters (a) baizid industrial hub, and (b) cepz readymade garment industries in chittagong city different types of industry. from those 72 are garments, 34 are textile and 61 are other industry. in this research study about 25 garments industries which are 155 of total industries and 34% of total garment industry. in our grading strategy, a large grade point was referred to a safer situation. therefore fire risk index (fri) was used as inverse scale. a higher fire risk index (fri) means less risk. on the other hand higher percentage of fire safety ensures safer condition, on the other hand lower percentage of deviation ensures safer condition. in this map, there about 80% garments industries were in excellent condition in this area. they were less than 10% deviation from ideal case and considered about very less vulnerable. on the other hand 20% were in good condition with deviation 10-20% from the ideal case and were considered less vulnerable. in those industries maximum 19.33% deviation from the ideal case, it is located in sector-1. it was under good condition but near about average condition. on the other hand minimum 2.8% deviations from ideal case, which is located in sector 6\{}a. in figure 6 yellow colour represents excellent condition of industries with less than 10% deviation from ideal case. on the other hand red colour indicates good condition with more than 10% deviation. 4. conclusions this study can be conducted to workers safety in case of emergency situation in rmg industry. the findings of such study may be used to further modify the fire safety system and operational management of rmg industries in chittagong city. codes and standards reflect that concern with special requirements. industrial fire incidents data is not available although fire hazard characterization information is available in the fire service and civil defence (fscd) stations. besides no mentionable vulnerability or safety assessment has been performed for this hazard of garments industry. as a result, fire hazard vulnerable industry which is not assessed for this hazard may break out fire and causes lots of human death and economic loss. this can negative affect our economy of the country. in the study area it has © 2019 the authors. page 26 of 28 islam et. al. indonesian journal of environmental management and sustainability, 3 (2019) 20-28 figure 7. level of vulnerability and risk of fire hazards at a) cepz area and b) baizid i/h, chittagong, bangladesh been found that in cepz area is more safe and sound than the baizid industrial area. as epz are export oriented heavy garments industries so all type of fire related equipment are sufficient in amount. it was sound good as both areas; the poor condition is totally absent. the electric short circuit was the prime case of fire hazards in the garments factories. for the frequent fire hazard in the last few years in the country, the government along with the garments owners is more watchful about fire hazards and regarding the fire as a crucial threat for their factories talking various imperative steps to reduce fire hazards. now, all the people concerned with this sector heeding much more concentration on fire hazards so that fire hazards can be dwindled and if occurs the loss of life and property can be diminished. the fire safety score can help to know about the safekeeping for the worker in their workplace. this type of study can help to make people conscious regarding fire hazard and also can minimize the different losses of the garments industry. 5. acknowledgement the author would like to thanks to the department of geography and environmental studies, university of chittagong, chittagong-4331, bangladesh for provide lab, equipments and seminar facilities in this research. references abdin, m. j. 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(1997). performance-based approaches to protecting our heritage. in boston: society of fire protection engineers yunus, m. and t. yamagata (2012). the garments industry in bangladesh: the report of dynamics of the garments industry in low income countries. technical report © 2019 the authors. page 28 of 28 introduction experimental section study area methods and materials primary field survey secondary data collections and analysis data presentation and analysis results and discussion existing fire safety deign in the rmg industries infrastructural deign and opportunities to safety fire hazard risk indexing by different parameters conclusions acknowledgement indonesian journal of environmental management and sustainability p-issn: 2598-6260 e-issn: 2598-6279 http://ijoems.com/index.php/ijems research article received: 8 december 2017 accepted:3 april 2018 *corresponding author email: rozirwan@unsri.ac.id, rozirwan@gmail.com doi: 10.26554/ijems 2018.2.20-2320 endophyte microbial characteristic of soft corals lobophytum sp and sinularia sp collected from maspari island waters, south sumatera rozirwan1, muhammad hendri1, rezi apri1 1marine science department, faculty of mathematic and natural science, sriwijaya university, indonesia 30662 abstract soft corals have bioactive compounds to potential as marine natural products, but the over exploitive to destroy of that ecosystem. therefor endophyte microbial isolation can be effort to prevent that matters. this research aimed to isolate and characteristic on the entophyte microbial of soft coral lobophytum sp and sinularia sp that collated from maspari island waters. methodology of research was establishing growth of microbial samples (bacterial and fungal), isolation and characterization. total of bacteria colony of lobophytum sp were obtained about five isolates, and sinularia sp were about four isolates. the macroscopic characteristic showed that whole bacteria had white colors. those colonies had undulate, entire and curl (the edge of colony) and circular and irregular (for colony shape). for fungal of lobophytum sp were obtained about three isolates, while sinularia sp had only one isolate. the fungal colonies macroscopic characteristic showed yellow, green and white color, while shaped and edges colonies were thickened. spread, thin, round, dark, and the whole of isolates had filamentous hyphae. keywords: entophyte microbial, lobophytum sp., sinularia sp., soft coral. 1. introduction soft corals have bioactive compounds that can be used antimicrobial [1-3]. over exploitative of soft corals can destroy of ecosystem due to their slow growth [4]. to utilize bioactive compounds on soft corals without damaging their habitat can use on endophyte microbes endophyte microbes are microbes that live inside their host and symbiotic with each other. they can produce the same bioactive compounds as their host. several studies have shown that endophyte microbes associated with soft corals have potential as antimicrobials [5, 6]. one of locations that can be found soft coral lobophytum sp and sinularia sp species is maspari island waters, south sumatera with position at bangka strait. some soft corals found on this island have potential as described earlier. therefore, a study of endophyte microbes those are symbiotic with coral soft lobophytum sp and sinularia sp species. 2. experimental section the research was conducted on september to october 2017. soft coral samples were used lobophytum sp and sinularia sp that collected from maspari island waters, south sumatera with coordinate position 3o 15’ 57” s and 106o 12’ 59” e. for soft coral identified refer to [7-10]. 2.1. establish culture of endophyte microbial soft coral sample (10 g, fresh weight) washed with sterile sea waters about 2 to 3 times and coped to smalls. for endophyte bacteria is grown in liquid zobell medium, and fungal in potato dextrose broth (pdb) (9:1 v/w). then it is incubated and shaker refer to [6]. 2.2 isolation of endophyte microbial isolation and characterization macros copies of endophyte bacterial were dilution, enrichment, plantation and observation under microscopies. a medium used autoclaved zobell solid medium about 20 ml in petri dish, respectively. the marine biota (coral, seaweed and mangrove) were grown medium, then it diluted of gradually (10-1, 10-2, 10-3, 10-4, 10-5 and 10-6). the last three dilutions were planted with pout plate technique. this method used refer to [6, 11, 12]. endophyte fungal isolation was dilution and plantation in medium potato dextrose agar (pda) that autoclaved about 15 ml in petri dish, respectively. this method used refer to [12, 13]. 2.3 purification of endophyte microbial the isolate bacteria grouped used macroscopic observed for purification and cultures with autoclaved zobell solid medium about 20 ml in petri dish, respectively. the isolate of endophyte bacteria author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.20-2321 inoculated 1 ose needle, and incubated at 280c for three days. the purification methods of bacteria used refer to [14]. for isolate fungal used autoclaved pda medium about 20 ml in petri dish, respectively. isolate of endophyte fungal must be a single colony, and then characterized refer to [15]. 3. results and discussion 3.1. endophyte bacteria of soft coral the result grown of endophytes bacteria showed produced of color, smell and foam that indicated bacteria grown in medium. day 1, media showed still not changed of color, smell and foam, while medium changed were day 4th to yellow of lobophytum sp species and dark brown of sinularia sp species as seen in figure 1. this was done bacteria began to grow can be seen from the change of color, smell and foam from the metabolic process. a color changes also occurred in [6] on samples of sinularia sp with in same medium that showed dark brown color. the result of isolation in petri dish was characterized by the growth of bacterial colonies. macroscopics characterization was done visually including elevation, edges, size and color of colony as seen in table 2. based on table 2 showed that bacteria colonies not grown in dilutions of 10-5 and 10-6. isolates grown on lobophytum sp samples were five pure isolates, while sinularia sp were four pure isolates as seen in figure 2. the bacteria isolated from the both samples had white colored, small sized and flat elevated colonies. for bacteria colonies from lobophytum sp showed edges had undulate and entire, shaped were circular and irregular. while bacteria of sinularia sp had colonies edges were undulate, entire and curl. isolates obtained [6] that had same shape of colony, but different characteristics other due to different samples [6]. the association bacteria of soft coral lobophytum sp were found 158 isolates [5]. bacterial isolates were obtained so large due to different sample treatments, which that isolates were carried out of endophyte and epiphytic. 3.2 endophyte fungal of soft coral physical characteristics that changed in liquid media such as color and smell showed indicated that endophyte fungus had occurred microbial growth process. for day 1 were not change of color and smell. the colors and smells changed dark yellow and stink (of lobophytum sp), and dark brown (of sinularia sp) had occurred day 4th as seen in figure 2. the result of fungal isolates was obtained three types with yellow, green and white color features of lobophytum sp sample, while only one fungus isolate type with white color of sinularia sp. there were obtained 15 isolates of fungal from sinularia sp and two of them had potential as antifungal, whereas had color of colony were white and black. it had different of this result due to treatment of sample, whereas she isolated epiphyte and endophyte on the fungal associates. based on table 3, fungal isolates were named code lb1, lb2 and lb3 on lobophytum sp sample, while named code sn1 only on sinularia sp. the lb1 isolate had colonies of yellow color, thickened and spread. lb2 had green color, thickened, mycelium regularly and black of colony edges. lb3 had white color, thin, round and dark of colony edges. while sn1 isolate had white color, thickened and spread, the whole of isolates had fibrous hyphae. there were obtained 15 fungus isolates from sinularia sp and two of them had potential as antifungal [16]. conclusion soft coral lobophytum sp and sinuaria sp species had endophyte table 1 compositions of zobell medium for endophyte bacterial isolate materials total agar* 15.0 g peptone 2.5 g yeast extract 0.5 g sea water 1.0 l * added for solid medium figure 1. culture of endophyte bacteria in liquid medium, a1) lobophytum sp of 1st day; a2) lobophytum sp of 4th day; a3) isolates of lobophytum sp; b1) sinularia sp of 1st day; b2) sinularia sp of 4th day; and b3) isolates of sinularia sp figure 2. culture of endophyte fungal in liquid medium, c1) lobophytum sp of 1st day; c2) lobophytum sp of 4th day; c3) isolates of lobophytum sp; d1) sinularia sp of 1st day; d2) sinularia sp of 4th day; and d3) isolates of sinularia sp author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.20-2322 microbial, where obtained endophyte bacterial and fungal. the bacterial colonies were found more in lobophytum sp compared to in sinularia sp, but the fungal colonies obtained in sinularia sp were more variable. the both soft coral samples had macroscopics characteristic of endophyte microbial were obtained white colors, small sized and flat elevated colonies for bacteria isolates, while for fungal isolates had yellow, green and white color features. the shapes of colonies were thickened. spread, thin, round, dark edge, and the whole of isolates had filamentous hyphae. acknowledgement this research funded by sriwijaya university of penelitian unggulan kompetitif tahun 2017. (grant no.: 988/un9.3.1/pp/2017). references [1] m. zhao, j. yin, w. jiang, m. ma, x. lei, z. xiang, j. dong, k. huang, and p. yan, "cytotoxic and antibacterial cembranoids from a south china sea soft coral, lobophytum sp," marine drugs, vol. 11, no. 4, pp. 1162-1172, 2013. [2] d. soedharma, m. kawaroe, and a. haris, "kajian potensi bioaktif karang lunak (octorallia: alcyonacea) di perairan kepulauan seribu, dki jakarta," jurnal ilmu-ilmu perairan dan perikanan indonesia, vol. 12, no. 2, pp. 121-128, 2005. [3] r. rozirwan, d. g. bengen, n. p. zamani, h. effendi, and c. chaidir, "screening on the potential bioactive compounds of antibacterial activity in soft coral collected from south bangka island waters and lampung bay," jurnal ilmu dan teknologi kelautan tropis, vol. 6, no. 2, pp. 283-295, 2014. [4] d. arafat, "pertumbuhan karang lunak (octocorallia: alcyonacea) lobophytum strictum, sinularia dura dan perkembangan gonad sinularia dura hasil fragmentasi buatan di pulau pramuka, kepulauan seribu, jakarta," master degree, marine science, ipb, bogor, 2009. [5] y. h. chen, j. kuo, p.-j. sung, y.-c. chang, m.-c. lu, t.-y. wong, j.-k. liu, c.-f. weng, w.-h. twan, and f.-w. kuo, "isolation of marine bacteria with antimicrobial activities from cultured and field-collected soft corals," world journal of microbiology and biotechnology, vol. 28, no. 12, pp. 3269-3279, 2012. [6] r. rozirwan, d. g. bengen, c. chaidir, n. p. zamani, and h. effendi, "bacterial symbiont bioactive compound of soft coral sinularia flexibilis and s. polydactyla," jurnal ilmu dan teknologi kelautan tropis, vol. 7, no. 2, 2015. [7] g. alen and r. steene, indo-pacific coral reef field guide. tropical reef research. australia: tropical reef research, 1996, p. 378. [8] k. k. fabricius and p. p. alderslade, soft corals and sea fans: a comprehensive guide to the tropical shallow water genera of the central-west pacific, the indian ocean and the red sea. twonsville mc: australian institute of marine science (aims), 2001, p. 272. [9] a. manuputty, "karang lunak (soft coral) perairan indonesia lipi," ed: jakarta, 2002. [10] r. rozirwan, d. bengen, n. zamani, and h. effendi, "the differences of soft corals spatial distributions between sheltered and exposed sites at pongok island in south of bangka and tegal island in lampung bay, indonesia," international journal of marine science, vol. 4, no. 65, pp. 1-7, 2014. [11] h. j. benson, microbiological applications; a laboratory manual in general microbiology. boston: mcgraw hill, 2002, p. 478. [12] j. g. cappuccino and n. sherman, microbiology: a table 2 macroscopic of endophyte bacteria colonies soft coral dilutions colony color colony size elevation boundary shape lobophytum sp. white (1) small flat undulate circular 10-4 white (2) small flat undulate circular white (3) small flat entire irregular white (4) moderate flat undulate irregular 10-5 na na na na na 10-6 na na na na na sinularia sp white (1) flat undulate circular 10-4 white (2) small flat entire circular white (3) small flat entire irregular white (4) small flat curl irregular white (5) small flat curl circular 10-5 na na na na na 10-6 na na na na na na: unavailable table 3 macroscopic of endophyte fungal colonies soft coral isolate code color shape hyphae lobophytum sp lb1 yellow thickened and spread filamentous lb2 green thickened, mycelium regularly and black of colony edge filamentous lb3 white thin, round and dark of colony edge filamentous sinularia sp sn1 white thickened and spread filamentous author, year | indones. j. env. man. sus. 1 (1) 2017: xx xx doi: 10.26554/ijems 2018.2.20-2323 laboratory manual (no. qr 63. c36 1996). glenview, usa: pearson education, inc., 2014, pp. 544-55. [13] s. purwantisari and r. b. hastuti, "isolasi dan identifikasi jamur indigenous rhizosfer tanaman kentang dari lahan pertanian kentang organik di desa pakis, magelang," bioma, vol. 11, no. 2, pp. 45-53, 2009. [14] o. k. radjasa, s. i. o. salasia, a. sabdono, j. wiese, j. f. imhoff, c. lämmler, and m. j. risk, "antibacterial activity of marine bacterium pseudomonas sp. associated with soft coral sinularia polydactyla against streptococcus equi subsp. zooepidemicus," international journal of pharmacology, vol. 3, no. 2, pp. 170-174, 2007. [15] r. q. ariyono, s. djauhari, and l. sulistyowati, "keanekaragaman jamur endofit daun kangkung darat (ipomoea reptans poir.) pada lahan pertanian organik dan konvensional," jurnal hama dan penyakit tumbuhan, vol. 2, no. 1, pp. pp. 19-28, 2014. [16] d. a. putri, o. k. radjasa, and d. pringgenies, "effectiveness of marine fungal symbiont isolated from soft coral sinularia sp. from panjang island as antifungal," procedia environmental sciences, vol. 23, no. supplement c, pp. 351357, 2015/01/01/ 2015. title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper bio-hydrogen production from vinasse by using agent of fermentation photosynthetic bacteria rhodobium marinum nusaibah1*, khaswar syamsu2, dwi susilaningsih3 1department of marine processing product, polytechnic of marine and fisheries pangandaran, pangandaran, 46396, indonesia 2department of biotechnology, postgraduate school bogor agricultural university, bogor, 16680, indonesia 3laboratory of bioenergy and bioprocess, indonesia institute of science, bogor, 16911, indonesia *corresponding author e-mail: nunus.hokudai@gmail.com abstract the aim of this research was to find out the effect of substrate concentrations (cod) of vinasse and the length of fermentation time to bio-hydrogen gas production using agent of fermentation photosynthetic bacteria, rhodobium marinum. the production of bio-hydrogen was examined by varying cod of vinasse (10,000; 20,000; 30,000; 40,000; 50,000 mg cod/l) at certain fermentation time in the third, sixth and ninth day. the highest hydrogen gas was obtained at ninth day of fermentation (82.66±18.6 ml). the highest hydrogen production rate (hpr) and cod removal rate were obtained at concentration 50,000 mg cod/l, namely 109.98 ml h2/l/d and 1437.66 mg cod/l/d, respectively. thus it can be concluded, the concentration of substrates (cod) from vinasse and the length of fermentation time have an effect on production of bio-hydrogen gas using rhodobium marinum. keywords bio-hydrogen, vinasse, rhodobium marinum received: 1 march 2020, accepted: 21 march 2020 https://doi.org/10.26554/ijems.2020.4.1.23-27 1. introduction hydrogen has long been considered as a fuel and alternative energy future. hydrogen is a clean fuel because it does not generate co2 gas emissions and can be easily used as a ”fuel cell” to generate electricity. in addition, hydrogen has a high energy of 122 kj/g, which is 2.75 times larger than hydrocarbon fuels. there are several conventional methods of hydrogen production including steam reforming of methane (srm), with other hydrocarbons (srh), a noncatalytic partial oxidation of fossil fuels (pox) and auto thermal reforming combining srm and pox. some of these methods require energy and the high temperatures (>850 °c) (kapdan and kargi, 2006). combustion of hydrogen will not cause the greenhouse effect, ozone depletion, or acid rain. the process of combustion produces only vapour and heat energy (nath and das, 2004). the producing of renewable energy economically should use cheap and readily available substrates so it can be used on an industrial scale. organic waste can be used as a substrate which is economical to produce bio-hydrogen. for example, urban waste, agricultural waste, solid and liquid waste from the organic industry (das and veziroglu, 2008). the advantages of using waste as a substrate, it can reduce the accumulation of wastes in the environment. the example of potential waste for the production of bio-hydrogen is vinasse. vinasse is a liquid waste product of the distillation ethanol production through fermentation of molasses. dos reis et al. (2015) mentions the cod content of vinasse is 42,818 mg/l. in general, vinasse has a low ph, blackish brown color contains many residues, organic and inorganic components. phenolic components (such as humic acid and tannic acid), melanoidin (the result of a reaction between sugars and proteins by maillard reaction), caramel and furfural components contributing gives the color of vinasse. some of these components which cause vinasse complex and difficult to be degraded. the amount of vinasse are overflow in this world, the distillation process of 110,000120,000 tons molasses can produce 70,000 vinasse tons per year (vaccari et al., 2005). in 2008, the production of vinasse in the world reaching more than 650 billion l arimi et al. (2015). the research on using vinasse for bio-hydrogen production has not been done, some research of bio-hydrogen production from vinasse have been carried out by júnior et al. (2015) which produced bio-hydrogen from vinasse with clostridium bacteria and pectinatus using the pack bed reactor with a working volume of 2.3 l. the results https://doi.org/10.26554/ijems.2020.4.1.23-27 nusaibah et. al. indonesian journal of environmental management and sustainability, 4 (2020) 23-27 was quite high, 509.5 ml h2/d/l. later studies of buitrón et al. (2014) bio-hydrogen produced about 57.4 ml h2/l/h using tequila vinasse as a substrate with thermal pre-treat anaerobic sludge as an inoculum bio-hydrogen producer. lazaro et al. (2014) produced hydrogen 1.72-2.23 mmol h2/g codinfluent using vinasse with microbial consortia at mesophilic temperatures. the aim of this research is to find out the effect of variation substrate concentrations of vinasse to bio-hydrogen gas production by using photosynthetic bacteria rhodobium marinum. 2. experimental section 2.1 materials the microorganisms used in this research was rhodobium marinum. the stock culture was obtained from nbrc (nite biological resource center) with the collection number 100434. substrates used in this research were vinasse obtained from pt. madu kismo, yogyakarta, indonesia. 2.2 methods 2.2.1 characterization of vinasse characterization vinasse was conducted by measuring the chemical oxygen demand (cod) (58,433 mg/l) following sni method (sni, 2009), total nitrogen (83.10 mg/l) and total organic acids (11.15%) were analyzed following aoac method (of official analytical chemists and of official agricultural chemists , us) and ph (3.63) were examined using ph meter (jenway 3505). 2.2.2 pre-treatment of vinasse pre-treatment were done in various stages of treatment such as by filtration, adjusted ph at 8 using naoh 10 n and sterilization by autoclaving (121 °c in 15 minutes). 2.2.3 bio-hydrogen production bio-hydrogen production was conducted by using a variation of cod concentration of vinasse. in this research variation of cod used were 10,000; 20,000; 30,000; 40,000; 50,000. photofermentation was performed using scott bottles of 120 ml, with a working volume of substrate 80 ml. substrate which has been pre-treated were inoculated with r. marinum (optical density ± 0.2). after inoculation, the substrate bottles were placed on a shaker at 120 rpm and irradiating fluorescent lamp (tubular lamp, philips) 60 watt/m2 at room temperature (30 °c). fermentation was carried out for third, sixth and ninth days. 2.2.4 analytical methods hydrogen gas were determined by gas chromatography using a thermal conductivity detector (tdc) with porapacked column. oven temperature were set at 250 °c and 150 °c respectively. the flow rate of carrier gas was used as a standard. calculations for composition of gases were accomplished using comparison area between samples and standard. cod assays were determined according to sni method (sni, 2009). 3. results and discussion the linier regression of bio-hydrogen gas and cod removal at various concentration were presented in figure 1 and 2. the result of hydrogen production rate and cod removal rate were presented in table 1 dan 2, then the chemical properties of substrate after production was presented in table 3. figure 1. linier regression of bio-hydrogen gas at various cod concentration (10,000-50,000 mg/l) figure 2. linier regression of cod removal at various cod concentration (10,000-50,000 mg/l) 3.1 pre-treatment of vinasse pre-treatment of vinasse was carried out so it can be an effective substrate for the production of bio-hydrogen by r. marinum bacteria. pre-treatment was carried out in various steps and finished with filtration, adjusting ph to 8 using 10 n naoh and sterilizing using autoclaves (121 °c for 15 minutes). filtration was carried out so the granules or solids are discarded. adjusting ph to 8 because the optimum ph for growth of r. marinum is 6.5 8.5. after adjusting the ph, sterilization was done using an autoclave (121 °c for 15 minutes). sterilization was needed to destroy all microbes that were not needed, so only r. marinum bacteria which should be able to produce bio-hydrogen. pre-treatment must be done because vinasse has the characteristics of having many solids and very acidic. the color of vinasse before and after pre-treatment was not change, the color of vinasse was remains blackish brown. the research of dos reis et al. (2015) states that the cod content of vinasse was 42,818 mg/l. in general, vinasse has a low ph, a blackish brown color that contains many residues, organic and inorganic components. phenolic components (such as humic acid and tannic acid), melanoidin (the result © 2020 the authors. page 24 of 27 nusaibah et. al. indonesian journal of environmental management and sustainability, 4 (2020) 23-27 table 1. result of bio-hydrogen production of various cod concentration (10,000-50,000 mg/l) cod days bio-hydrogen production conc. hydrogen hydrogen production (mg/l) gas (ml) rate (mlh2/l/d) 10,000 3 16.63 ±3.08 12.76 6 14.47 ± 1.55 9 10.92 ± 0.87 20,000 3 29.49 ± 3.23 36.63 6 30.31± 3.26 9 29.03 ± 6.57 30,000 3 37.96 ± 2.93 71.65 6 49.36 ± 6.84 9 53.52 ± 2.67 40,000 3 43.52 ± 8.37 99.23 6 63.32 ± 2.54 9 72.78 ± 13.2 50,000 3 38.91 ± 0.68 109.98 6 54.88 ± 16.4 9 82.66 ± 18.6 of the reaction between sugar and protein by the maillard reaction), caramel and furfural components that contribute to give color to vinasse. some of these components cause complex vinasse and are difficult to degrade. according to garćıa-sánchez et al. (2018) the cod content in vinasse tequila was 22,085 ± 1325 mg/l. the organic components of vinasse tequila were carbohydrates (7.4 g/l), lactate (4.7 g/l) and other short chain organic acids (2.6 g/l). then according to lazaro et al. (2014), vinasse is also toxic because it contains potassium, sulfate, phenolic components and melanoidin. after pre-treatment, vinasse was ready to be used as a substrate for bio-hydrogen production. 3.2 bio-hydrogen production after a preliminary study, the production of bio-hydrogen using vinasse was done with various concentrations of 10,00050,000 mg/l cod vinasse. the result was presented in table 1 and fig. 1. the highest hydrogen production rate (hpr) achieved at the concentration of 50,000 mg/l (109.98 ml h2/mg cod/d), while the lowest hpr generated at concentration of 10,000 mg/l (12.76 ml h2/mg cod/d). at the concentration of 20,000-50,000 mg/l cod, bio-hydrogen gas volumes rise significantly from third day to ninth day, except concentration of 10,000 mg/l decline from third day to ninth day. there are many factors that affect the production of bio-hydrogen with a wide range of substrate concentration. according to buitrón and carvajal (2010) the substrate concentration of vinasse has two effect on the production of bio-hydrogen, (a) the substrate concentration can potentially become a barrier and (b) there are some concentrations that can maximize the production of bio-hydrogen. which can be a barrier of bio-hydrogen production from vinasse is the accumulation of organic acids that are generated when a process takes place and the presence of toxic components in vinasse like phenolic components and furfural. the research also indicates a difference of metabolic pathways that are prominent in every different vinasse concentration (lazaro et al., 2014). the concentration of 10,000 mg/l cod vinasse was obtained the lowest hpr of the entire treatment. from the fig.1, it can be seen that bio-hydrogen gas was decline from third day to ninth day. the highest gas earned on third day and lowest on ninth day, it was suspected because of the carbon source on production of media has run out on third day, so all that’s left was the toxic compounds like phenolic compounds and furfural (lazaro et al., 2014). in addition, the decrease of bio-hydrogen gas can also be affected by the differences of cod concentration that affect metabolic pathways at each concentration so the results also vary. a low concentration of vinasse can affect the production of propionic acid. furthermore, according to kim et al. (2008), hydrogen is not produced if the by-product are the lactic acid and propionic acid. levels of cod removal upon the concentration of 10,000 mg/l cod can be seen in fig.2. the highest level of cod removal was on third day and the lowest on ninth day. cod removal rate at this concentrations was the lowest from all treatment. efficiency substrates of this concentration highest on third day and lowest on ninth day (table 2). the result of hydrogen production rate (hpr) of concentration 20,000 mg/l cod can be seen in table 1 and fig. 1 (36.63 ml h2/mg cod/d). the highest bio-hydrogen gas achieved in the sixth day and lowest on the ninth day. bio-hydrogen gas in this concentration was higher than concentration of 10,000 mg/l. the levels of cod removal was assumed to be the maximum cod levels that can be used by r. marinum to produce bio-hydrogen at concentration 20,000 mg/l (table 2, fig.2). cod removal rate at this concentrations was higher than concentration of 10,000 mg/l. the concentration of 30,000 cod mg/l obtained hpr namely 71.65 ml h2/mg cod/d. bio-hydrogen gas in this concentration has increased from third day to ninth day and higher than previous concentration. hpr and cod removal rate were also higher than previous concentration. the highest efficiency of substrate at this concentration was on the ninth day and lowest on third day. the concentration of 40,000 mg/l cod vinasse has obtained hpr 99.23 ml h2/mg cod/d. hpr and cod removal rate this concentrations were higher than previous concentration. the concentration of 50,000 mg/l cod achieved the highest volume of bio-hydrogen gas, hpr and cod removal rate of the entire concentration (table 1, 2 and fig.1, 2). the efficiency of the substrate on this concentration is also the highest of the whole concentration. this was allegedly due to more levels of cod concentration were used then the more bio-hydrogen gas also produced. having regard to the © 2020 the authors. page 25 of 27 nusaibah et. al. indonesian journal of environmental management and sustainability, 4 (2020) 23-27 table 2. result of efficiency substrate and cod removal cod days efficiency cod cod conc. of removal removal rate (mg/l) substrate (%) (mg/l) (mg cod/l/d) 10,000 3 23.58 2120.00±47.1 159.33 6 22.34 2020.00±94.2 9 17.44 1626.66±365.3 20,000 3 14.56 2353.34±235.6 534.33 6 17.73 3253.33±612.8 9 26.27 5043.33±624.6 30,000 3 10.11 2786.67±23.5 815.44 6 19.03 5686.66±612.8 9 24.75 7192.67±718.8 40,000 3 12.17 4036.66±860.3 865.44 6 19.07 6720.00±471.3 9 20.75 7760.00±282.8 50,000 3 9.19 3586.67±412.2 1437.66 6 14.86 6386.67±141.4 9 30.06 13443.33±954 table 3. chemical properties of substrate after production cod conc. days total organic ph (mg/l) acid (%) 10,000 3 0.03 6.19 6 0.19 6.01 9 0.11 5.94 20,000 3 0.13 6.06 6 0.2 5.94 9 0.22 5.91 30,000 3 0.18 6.05 6 0.26 5.95 9 0.28 5.98 40,000 3 0.19 6.11 6 0.37 6.03 9 0.41 5.97 50,000 3 0.15 6.1 6 0.25 6.16 9 0.39 6.05 length of fermentation and other factors that affect the production of bio-hydrogen optimally. some of the research that uses vinasse substrate for the production of bio-hydrogen were research of buitrón et al. (2014), resulting hpr in 57.4 ml h2/l-h using substrate tequila vinasse with thermal pre-treat anaerobic sludge as an inoculum bio-hydrogen producer. the research of santos et al. (2014) produced hydrogen effectively amounted to 0.79 mmol/g cod on substrate concentration vinasse of 30,000 mg cod/l. 3.3 chemical properties of substrate after production the chemical properties showed that total organic acids substrate after production was reduced but still available. the total organic acids of vinasse was 11.15 mg/l, and reduces gradually. ph of substrates after pre-treatment was 8, but after productions decreased into range (5.91-6.19). this is due to study by budiyono et al. (2013)), the decrease of ph can be caused by the accumulation of vfa production when vinasse is decomposed. when vinasse is decomposed into biogas, biogas will be produced without going through the hydrolysis phase but direcly into acidogenesis phase. in the phase of acidogenesis, the short chain molecular component is converted into vfa. 4. conclusions the differences of cod concentration and the length of fermentation time have an effect on bio-hydrogen gas production and hydrogen production rate (hpr). the highest levels of bio-hydrogen gas, hpr and cod removal rate were achieved at 50,000 mg/l cod. thus it can be concluded that the concentration of cod vinasse and the length of fermentation time have an effect on production of bio-hydrogen gas using rhodobium marinum. 5. acknowledgement this research was supported by a grant competitive programme 2015 from research center for biotechnology, indonesia institute of science. © 2020 the authors. page 26 of 27 nusaibah et. al. indonesian journal of environmental management and sustainability, 4 (2020) 23-27 references arimi, m. m., j. knodel, a. kiprop, s. s. namango, y. zhang, and s.-u. geißen (2015). strategies for improvement of biohydrogen production from organic-rich wastewater: a review. biomass and bioenergy, 75; 101– 118 budiyono, b., , i. syaichurrozi, and s. sumardiono (2013). biogas production from bioethanol waste: the effect of ph and urea addition to biogas production rate. waste technology, 1(1); 1–5 buitrón, g. and c. carvajal (2010). biohydrogen production from tequila vinasses in an anaerobic sequencing batch reactor: effect of initial substrate concentration, temperature and hydraulic retention time. bioresource technology, 101(23); 9071–9077 buitrón, g., g. kumar, a. martinez-arce, and g. moreno (2014). hydrogen and methane production via a two-stage processes (h 2 -sbr ch 4 -uasb) using tequila vinasses. international journal of hydrogen energy, 39(33); 19249– 19255 das, d. and t. veziroglu (2008). advances in biological hydrogen production processes. international journal of hydrogen energy, 33(21); 6046–6057 dos reis, c. m., m. f. carosia, i. k. sakamoto, m. b. a. varesche, and e. l. silva (2015). evaluation of hydrogen and methane production from sugarcane vinasse in an anaerobic fluidized bed reactor. international journal of hydrogen energy, 40(27); 8498–8509 garćıa-sánchez, r., r. ramos-ibarra, g. guatemalamorales, e. arriola-guevara, g. toriz-gonzález, and r. i. corona-gonzález (2018). photofermentation of tequila vinasses by rhodopseudomonas pseudopalustris to produce hydrogen. international journal of hydrogen energy, 43(33); 15857–15869 júnior, a. d. n. f., c. etchebehere, and m. zaiat (2015). mesophilic hydrogen production in acidogenic packed-bed reactors (apbr) using raw sugarcane vinasse as substrate: influence of support materials. anaerobe, 34; 94–105 kapdan, i. k. and f. kargi (2006). bio-hydrogen production from waste materials. enzyme and microbial technology, 38(5); 569–582 kim, d. h., s. h. kim, i. b. ko, c. y. lee, and h. s. shin (2008). start-up strategy for continuous fermentative hydrogen production: early switchover from batch to continuous operation. international journal of hydrogen energy, 33(5); 1532–1541 lazaro, c. z., v. perna, c. etchebehere, and m. b. a. varesche (2014). sugarcane vinasse as substrate for fermentative hydrogen production: the effects of temperature and substrate concentration. international journal of hydrogen energy, 39(12); 6407–6418 nath, k. and d. das (2004). biohydrogen production as a potential energy resource–present state-of-art. journal of scientific and industrial researc of official analytical chemists, a. and a. of official agricultural chemists (us) (1920). official methods of analysis santos, s. c., p. r. f. rosa, i. k. sakamoto, m. b. a. varesche, and e. l. silva (2014). hydrogen production from diluted and raw sugarcane vinasse under thermophilic anaerobic conditions. international journal of hydrogen energy, 39(18); 9599–9610 sni (2009). air dan air limbah bagian 73: cara uji kebutuhan oksigen kimiawi (chemical oxygen demand/cod) dengan refluks tertutup secara titrimetri vaccari, g., e. tamburini, g. sgualdino, k. urbaniec, and j. klemeš (2005). overview of the environmental problems in beet sugar processing: possible solutions. journal of cleaner production, 13(5); 499–507 © 2020 the authors. page 27 of 27 introduction experimental section materials methods characterization of vinasse pre-treatment of vinasse bio-hydrogen production analytical methods results and discussion pre-treatment of vinasse bio-hydrogen production chemical properties of substrate after production conclusions acknowledgement title indonesian journal of environmental management and sustainability e-issn:2598-6279 p-issn:2598-6260 research paper traffic intersections noise levels and daily noise exposure in chandrapur city, central india akash c. gedam1, priyanka v. patil1, rahul k. kamble1* 13centre for higher learning and research in environmental science sardar patel college, ganj ward, chandrapur 442 402, india *corresponding author e-mail: rahulkk41279@yahoo.com abstract noise level monitoring was carried out at nine important traffic intersections of the chandrapur city to ascertain noise levels and daily noise exposure. a pre-calibrated mini sound level meter was used for noise measurement. observations were recorded for 24 hours and noise level during the day, night and for 24-hours was computed. maximum noise level during daytime was 84.27 db(a) at bangali camp square; whereas, minimum 79.23 db(a) at priyadarshani square. in case of nighttime maximum 85.90 db(a) was at warora naka square and minimum 70.06 db(a) at the jatpura gate. minimum noise level during 24-hours was at bagla square 84.34 db(a) and maximum 91.14 db(a) at warora naka square. noise level during day and night were above the indian noise standard for the commercial area. the bangali camp square was identified as the most ear-splitting square during daytime and warora naka square at nighttime and for 24-hours also. peak noise was recorded from 10.00 am to 11.00 am and 3.00 pm to 7.00 pm. vehicular noise, horns, and improper road design contributed significantly to noise levels at traffic intersections. daily noise exposure analysis by health and safety executive, uk software revealed bangali camp square and ramnagar police station square’s daily noise exposure for 0.25 hour was maximum 70 lep,d and minimum at gandhi square and bagla square 65 lep,d. noise levels indicated no immediate effect for hearing loss. control measures for reduction of noise levels at traffic intersections have also been proposed. keywords chandrapur, noise exposure, noise pollution, traffic intersection, traffic noise received: 28 agustus 2019, accepted: 24 september 2019 https://doi.org/10.26554/ijems.2019.3.3.80-92 1. introduction noise can be defined as the sound which exceeds the acceptable level and creates annoyance. the major sources of noise are industrial, vehicular, and community. out of these three, the source that affects the most is the traffic noise. almost 70% of the noise is contributed by vehicular noise. the recognition of vehicular traffic noise is one of the main sources of environmental pollution. due to increase in population, urbanization and rapid industrialization, there is a significant increase in vehicular number in urban areas which had lead to traffic problems. traffic noise from highways creates problems for surrounding areas, especially when there is heavy traffic volume and speed (karibasappa et al., 2015). noise pollution is one of the important issues of environmental pollution in metropolitan areas. being one of the most harmful agents, many countries had introduced noise standards for vehicles and other legislation to reduce road traffic noise (ross and wolde, 2001). motor vehicles are the main source of noise pollution in the urban environment. therefore, the urban masses are exposed to high noise level due to traffic on road, at the workplace as well as in transit. noise pollution is quantitatively measured in term of equivalent noise level (leq). the total acoustical energy released to the surrounding environment by the traffic distributed unevenly over the different frequency octave within the audible range from 20 to 20,000 hz (mohan et al., 2000). urban areas are majorly under the cover of traffic noise. traffic noise produces disturbance and adverse effects on individuals as compared to other sources of noise. according to central pollution control board road traffic contributes around 55% of total noise contamination. in urban areas, engines and fumes, arrangement of automobile, litter trucks, transports and two-wheelers are the contributors of traffic noise (sankhat et al., 2017). road traffic noise in europe accounts for more than 90% of unacceptable noise levels (daytime laeq > 65 db(a)) (filip et al., 2002). in india, traffic mix is usually heterogeneous and conditions of traffic congestions and interruption https://doi.org/10.26554/ijems.2019.3.3.80-92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 table 1. traffic intersection details traffic no. of roads at fleet composition traffic light intersection traffic traffic flow intersection the intersection presence typology volume typology janata four two-wheelers (moped); yes traffic heavy pulsed college four wheelers (cars); light continuous square heavy vehicles (trucks, buses) controlled flow warora two-wheelers (moped); yes planar heavy fluid naka four wheelers (cars); continuous square four heavy vehicles (trucks, buses) flow ramnagar four two-wheelers (moped); yes traffic light heavy pulsed police station four wheelers (cars); with a continuous square heavy vehicles (trucks, buses) roundabout flow priyadarshani four two-wheelers (moped); yes traffic heavy pulsed square four wheelers (cars); light continuous heavy vehicles (trucks, buses) controlled flow bangali four two-wheelers (moped); yes traffic light heavy pulsed camp four wheelers (cars); with a continuous square heavy vehicles (trucks, buses) roundabout flow gandhi three two-wheelers (moped); no planar medium pulsed square four wheelers (cars); continuous heavy vehicles (buses) flow girnar three two-wheelers (moped); yes traffic pulsed square four wheelers (cars); light continuous heavy vehicles (buses) controlled medium flow jatpura three two-wheelers (moped); no planar medium pulsed gate four wheelers (cars); decelerated square heavy vehicles (buses) flow bagla four two-wheelers (moped); no planar light pulsed square four wheelers (cars); continuous flow are very frequent and further heavy traffic volumes, higher speeds, and a greater number of trucks and buses also contribute the loudness of traffic noise. inappropriate stoppage of buses at locations rather than designated one also contributes traffic congestions on roads. besides, as the roads are narrower and different types of vehicles are not plying separately on the road lanes create declaration and acceleration noises as vehicles approach and depart from each other city (rajkumara and gowada, 2009). after carrying out an online and published literature review for noise levels at traffic intersections and exposure analysis for the chandrapur city, it was found that no such study was carried out previously. hence, a gap was identified. to fill this knowledge gap by generating a new one in this subject domain this study was proposed to carry out. the main objective of the study was to assess existing noise levels in different traffic intersections of the chandrapur city. furthermore, noise level exposure analysis to individual and traffic policemen/women who were deployed to manage traffic flow at these intersections. figure 1. chandrapur district map (satapathy et al., 2009) © 2019 the authors. page 81 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 table 2. noise levels at traffic intersections time janata warora ramnagar priyadarshani bangali gandhi girnar jatpura bagla (hour) college naka police station square camp square square gate square square square square square square noise level in db(a) 7.00 am 72.1 72.7 74.3 72.5 80.7 69 71.4 68.8 71.9 8.00 am 71 73.2 76.9 71.1 71.9 71.5 70.1 70.5 73.2 9.00 am 73.8 73.4 68.4 71.3 74.1 70.5 71.9 70.4 73.8 10.00 am 77.6 74.3 77.3 74.2 79.2 74.9 76.2 76.9 76.7 11.00 am 75.2 79.7 72.4 71.9 79.3 71.8 79 75 69.3 12.00 pm 66.1 71.5 73.2 72 76.8 70.2 68.4 77.3 69.4 1.00 pm 66.1 68 73.4 72.3 65.6 72.4 68.9 71 69.9 2.00 pm 69 70.3 77.7 69.8 68.5 67.9 64.5 68.8 68.1 3.00 pm 72.5 74.3 76.6 61.7 74.5 69.9 71.2 69.1 75.3 4.00 pm 68.9 71.1 79.3 51.2 69.2 68.3 70.2 69 59.1 5.00 pm 66.4 65.2 72.8 52.4 59.5 61.3 65.2 74.6 58.2 6.00 pm 66.5 66.6 59.4 59.4 60.5 58.4 60 70 60.3 7.00 pm 63.3 61.5 58.7 59.8 61.6 59.3 61.8 69.7 58.1 8.00 pm 63.5 62.9 56.6 59.8 63.8 63.2 62.4 71 65.1 9.00 pm 57.4 59.6 58.9 61.2 58.8 51.9 54.6 70.8 59.6 10.00 pm 54.5 55.4 63.9 64.1 55.4 54.3 52.1 66.9 57.5 11.00 pm 59.3 58.4 55.6 65.7 56.9 59.3 55.6 58.7 61.1 12.00 am 59.6 57.7 54.2 70.9 58.6 71.3 57.2 60 56.6 1.00 am 68 69.5 62.3 74.2 67.8 65.8 70 60.7 61.5 2.00 am 69.9 71 67.4 66.8 65.9 68 67.9 55.9 66.6 3.00 am 74.3 77.2 71.4 71.3 65.2 75.9 72.5 48.8 71.4 4.00 am 77.2 76.1 69.5 74.5 72.4 75.2 72.5 47.5 74.1 5.00 am 70.1 72.2 75.4 69.5 73.6 63.5. 60.5 60.4 67.8 6.00 am 76.2 88.4 75.5 76.1 83.3 74.8 75.9 70.8 72.4 min. 54.5 55.4 54.2 51.2 55.4 51.9 52.1 47.5 56.6 10.00 10.00 12.00 4.00 10.00 9.00 10.00 4.00 12.00 pm pm pm pm pm pm pm pm pm max. 77.6 88.4 79.3 76.1 83.3 75.9 79 77.3 76.7 10.00 6.00 4.00 6.00 6.00 3.00 11.00 12.00 10.00 am am am am am am am am am average 68.27 69.59 68.79 67.23 68.46 67.17 66.66 66.77 66.54 std. dev. 6.31 7.69 8.01 7 8.15 6.83 7.26 8.01 6.5 min. minimum, max. maximum, std. dev. standard deviation (±). © 2019 the authors. page 82 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 table 3. noise levels during day, night and 24-hours at traffic intersections traffic intersection noise level during noise level during noise level during daytime (ld) db(a) nighttime (ln) db(a) 24-hours (ldn) db(a) janata college square 80.94 78.84 85.87 warora naka square 82.18 85.9 91.14 ramnagar police station square 84.06 76.87 87.3 priyadarshani square 79.23 78.23 84.93 bangali camp square 84.27 81.03 88.85 gandhi square 79.26 77.85 84.73 girnar square 81.17 76.42 85.14 jatpura gate 82.32 70.06 84.77 bagla square 80.56 75.27 84.34 minimum 79.23 70.06 84.34 maximum 84.27 85.9 91.14 average 81.55 77.83 86.34 std. dev. 1.83 4.27 2.31 std. dev. standard deviation (±). table 4. national ambient air quality standards in respect of noise area category of limit in db(a) leq* code area/zone daytime night time a industrial 75 70 zone b commercial 65 55 zone c residential 55 45 zone d silence 50 40 zone note: 1. daytime shall mean from 6.00 a.m. to 10.00 p.m. 2. nighttime shall mean from 10.00 p.m. to 6.00 a.m. 3. silence zone is defined as an area comprising not less than 100 meters around hospitals, educational institutions, and courts. the silence zones are zones which are declared as such by the competent authority. 4. mixed categories of areas may be declared as one of the four abovementioned categories by the component authority. *db(a) leq denotes the time-weighted average of the level of sound in decibels on scale a which is related to human hearing ”a”, in db(a) leq, denotes the frequency weighting in the measurement of noise and corresponds to frequency response characteristics of the human ear leq: it is an energy mean of the noise level over a specified period figure 2. sampling locations from the study area. (a) janata college, (b) warora naka, (c) ramnagar police station, (d) bangali camp and (e) jatpura gate © 2019 the authors. page 83 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 table 5. daily noise exposure at traffic intersections traffic noise level duration of exposure to traffic noise intersection during daytime 0.25 hour 1 hour 2 hours 4 hours 6 hours 8 hours 10 hours (ld) db(a) a b a b a b a b a b a b a b janata 80.94 65 1 72 5 75 10 78 20 80 29 81 39 82 49college square warora 82.18 68 2 73 7 76 13 79 26 81 39 82 52 83 65naka square ramnagar 84.06 70 3 75 10 78 20 81 40 83 60 84 81 85 101police station square priyadarshani 79.23 65 1 70 3 73 7 76 13 78 20 79 26 80 33 square bangali 84.27 70 3 75 11 78 21 81 42 83 63 84 85 85 106camp square gandhi 79.26 65 1 70 3 73 7 76 13 78 20 79 27 80 33 square girnar 81.17 65 1 72 5 75 10 78 21 80 31 81 41 82 52 square jatpura 82.32 68 2 73 7 76 13 79 27 81 40 82 54 83 67 gate bagla 80.56 65 1 71 4 75 9 78 18 79 27 81 36 82 45 square minimum 79.23 65 1 70 3 73 7 76 13 78 20 79 27 80 33 maximum 84.27 70 3 75 11 78 21 81 42 83 63 84 85 85 106 a daily noise exposure (lep,d), b exposure point’s (jobs/tasks). figure 3. cluster analysis. (a) daytime, (b) nighttime, (c) for 24-hours, (d) noise exposure at a traffic intersection (0.25 hour) and (e) at combinations of traffic intersections 1.1 study area chandrapur formerly ‘chanda’ (19.57o n latitude and 79.18o e longitude) is a city and municipal corporation in chandrapur district of maharashtra state of india (figure 1). the city is situated at an altitude of 189.90 m above sea level and has a geographical area of 70.02 sq km. the north-south length of the city is about 10.6 km, while the east-west is about 7.6 km. in a 2011 state cabinet decision, chandrapur municipal corporation was elevated to d grade municipal corporation. the city has 67 wards and divided into 3 zones. according to the 2011 census of india, the city had a population of 375,000. the chandrapur city is a 13-century historic fort city which is divided into two, the old city which is situated inside the fort and new outside it. the old city is haphazardly settled with narrow by lanes and congested traffic intersections. the new city is systematically settled with proper town planning. the total road length of the city is 495.36 km. different types of roads in the city include concrete road 56.58 km, tar road 188.16 km, pedestrian road 140.02 km and unpaved road 110.60 km. national highway nh 930 (four lanes with divider) passes from north to east © 2019 the authors. page 84 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 table 6. noise exposure at combinations of traffic intersections traffic intersection duration of noise daily noise exposure combinations exposure at each exposure point’s (abbreviation) intersection (hour) (lep,d) (jobs/tasks) ramnagar police 0.25 73 6 station square and bangali camp square (rb) janata college 0.25 70 3square and warora naka square (jw) warora naka 0.25 72 5 square and ramnagar police station square (wr) ramnagar police 0.25 71 4 station square and priyadarshani square (rp) priyadarshani square 0.25 71 4and bangali camp square (pb) janata college 0.25 73 6 square; warora naka square and ramnagar police station square (jwr) ramnagar police 0.25 73 7 station square; priyadarshani square and bangali camp square (rpb) gandhi square; 0.25 71 4girnar square and jatpura gate square (ggj) table 7. damage risk criteria for hearing loss occupational safety and health administration (osha) maximum allowable noise level db (a) duration per day, hour (slow response) 8 90 6 92 4 95 3 97 2 100 1.5 102 1 105 0.5 110 0.25 or less 115 direction of the city connecting warora to chandrapur and further chandrapur to mul. state highway sh 264 connects chandrapur to ballarpur and major state highway msh 6 connecting chandrapur to ghugus. presently, there is no outer ring road for the city as a result of which heavy vehicles (four wheelers and long vehicles) passes from this national highway nh 930 through the city. to cater to the needs of inhabitants of the city limited public transport system is operated by chandrapur municipal corporation from anchaleshwar gate to urjanagar. in addition, private bus operators (intercity) also provide bus service from various parts of the city. state bus terminal connects the city to various parts of maharashtra and adjoining telangana state. the city has two railway stations. chandrapur railway station is situated on new delhi-chennai route and chanda fort station on bangalore-gorakhpur route. both stations connect the city to major parts of india. the city has two main roads (one way only) namely, © 2019 the authors. page 85 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 table 8. pearson correlation coefficient among various variables variable person correlation sig. detail coefficient (r) (1-tailed) number of roads r = -0.473 0.099merging at intersections and noise level during 24-hours (ldn) traffic light r = -0.559 0.059 presence at intersections and noise level during 24-hours (ldn) traffic volume r = -0.623* 0.037 *correlation is (heavy, medium, light) significant at the at intersections and 0.05 level (1-tailed) noise level during 24-hours (ldn) noise level during r = 0.110 0.389 daytime (ld) and noise level during nighttime (ln) noise level during r = 0.804** 0.004 **correlation is s daytime (ld) and ignificant at the noise level during 0.01 level (1-tailed) 24-hours (ldn) noise level during r = 0.611* 0.04 *correlation is nighttime (ld) and significant at the noise level during 0.05 level (1-tailed) 24-hours (ldn) noise level during r = 0.930** 0 **correlation is s daytime (ld) and ignificant at the daily noise exposure 0.01 level (1-tailed) (lep,d) for 0.25 hour table 9. correlation matrix for day, night and 24-hours noise level day night 24-hours correlation day 1 0.11 0.611 night 0.11 1 0.804 24-hours 0.611 0.804 1 sig. day 0.389 0.04 (1-tailed) night 0.389 0.004 24-hours 0.04 0.004 mahatma gandhi road and kasturba road. along both the sides of these one-way number of shops and other commercial activities are carried out. footpaths are present however are occupied by shopkeepers for sunday market near gandhi square. limited parking facilities are made available for two-wheelers and auto-rickshaws at selected locations along the roadside. these roads carry the entire city traffic from pathanpura gate in the remote south end to the north to jatpura gate and onwards to civil lines and government offices complex. the city traffic further disperses to warora, nagpur and towards north to chandrapur super thermal power station, coal mines and to tadoba andhari tiger reserve. the traffic towards the north further leads towards east to mul and gadchiroli–the other important neighboring urban centers. jatpura gate which serves as an entrance point to the city creates daily traffic congestion during afternoon hours. vehicular demography as of 31st march 2011 of the city includes motorcycles 139343, scooters 401613, mopeds 44690, motor cars and jeeps 21466, auto-rickshaws © 2019 the authors. page 86 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 table 10. principal component analysis component initial eigen values extraction sums of squared loadings componenta total % of cumulative total % of cumulative 1 variance % variance % 1 1.11 55.488 55.488 1.11 55.488 55.488 day 0.745 2 0.89 44.512 100 night 0.745 extraction method: principal component analysis, one component extracted. figure 4. scatter plots. (a) number of roads merging at intersections versus noise levels, (b) traffic light presence or absence versus noise levels and (c) traffic volume versus noise levels 6852, trucks, lorries and tankers 7961 and tractors and trailers 12654 (motor transport statistics of maharashtra, 2010-2011). the vehicular growth rate in the chandrapur region was 8.25% during 2012-13 to 2013-14; 8.30% from 2013-14 to 2014-15 and 8.69% for the period of 2014-15 to 2015-16. 2. experimental section 2.1 noise sampling and analysis the chandrapur city has number of traffic intersections. out of these intersections, nine were selected for the study by stratified sampling and on the basis of design of intersections. janata college square (figure 2a) is a traffic light controlled intersection; whereas, warora naka square (figure 2b) with a planar type intersection typology. ramnagar police station square (figure 2c) and bangali camp square (figure 2d) are traffic light controlled with a roundabout. ramnagar police station traffic intersection is comparatively wider than bangali camp square. jatpura gate traffic intersection (figure 2e) with a narrow entry through a gate serves as an entrance for the old chandrapur city. at this intersection traffic volume was medium with pulsed decelerating flow typology. traffic intersections identified for the study along with details such as numbers of roads merging at the intersection, fleet composition along with presence of traffic light, volume and flow typology is presented in table 1. from the table, it can be seen that at all traffic intersections two wheelers, four wheelers, and heavy vehicles were dominating. it can be further observed, 66.66% (n=6) traffic intersections had four roads merging; whereas, 33.33% (n=3) had three roads. it can also be pointed out that traffic intersections in the old city had three roads merging, on the other hand, those in the periphery and outskirt of the city had four roads. ambient noise levels at various traffic intersections of the city were monitored in 2017. sound pressure level (spl) measurements were recorded with a precision mini sound level meter (center 325 sound level meter iec 651 type ii, made in taiwan) which was calibrated before measurements were carried out. noise levels were recorded in “a” weighting. measurements were recorded at receiver’s position 1.2 m above ground level and away from any reflecting object. noise monitoring was carried out for 24 hours day and night so as to compare the difference in noise level and compute © 2019 the authors. page 87 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 noise level during daytime (ld), nighttime (ln) and during 24-hours (ldn). a noise rating method developed by the us environmental protection agency (us epa) for community noise from all sources was used. it is similar to 24 hours equivalent sound levels except that during nighttime a 10 db(a) correction is added to the instantaneous sound levels before computing 24 hours average. the nighttime penalty is added to account for the fact that noise at night when people are trying to sleep is judged more annoying than the same noise during the daytime. ldn for a given location is calculated from hourly equivalent sound levels (leq) using the following formula: ldn = 10log1/24[15(10ld/10) + 9(10(ln + 10)/10)] (1) where, ld equivalent noise level during daytime (0600 to 2200 hours) ; ln equivalent noise level during nighttime (2200 to 0600 hours). 2.2 noise exposure noise exposure calculator developed by the health and safety executive (hse), uk was used to calculate noise exposure to traffic policeman/women deployed at traffic intersections and commuters on road. the exposure calculator calculates exposure point’s job per task and exposure points per hour by considering noise level and exposure duration in hours. these exposure points can be used to prioritize noise control. the highest exposure points make the greatest contributions to daily noise exposure. thus, controlling these noise exposures will have greatest effect on daily noise exposure. commuters spend variable time on street and at traffic intersections. an attempt was also carried out in this study to calculate noise exposure at two and three traffic intersections combinations for varying duration (0.25-10 hours). in addition, a questionnaire-based field survey was also carried out for assessing noise exposure to traffic personnel and shopkeepers of the city. 2.3 statistical analysis the data on noise level, number of roads merging at intersections, presence of traffic light, traffic volume, noise level during daytime-nighttime, noise level during daytime-24hours noise level, noise level during night-24-hours noise level and daily noise exposure were statistically analyzed with the help of pearson correlation coefficient (r) by using spss to understand the strength of the relationship between these variables. furthermore, cluster analysis was applied to identify traffic intersections with similar or comparable noise level during day, night and 24-hours. cluster analysis was formulated according to ward algorithmic method. outcomes were shown in dendrograms, which illustrated hierarchical arrangement of resulting clusters, and values of the distance between clusters (square euclidean distance) were represented. a correlation matrix was used to identify the relationship between day, night and 24-hours noise levels at various intersections (richard and gregory, 1985). principal component analysis (pca) was used to infer the traffic noise source (anthropogenic or vehicular). 3. results and discussion 3.1 noise levels at traffic intersections hourly noise level at traffic intersections of the city at nine sampling locations is presented in table 2. from the observations reported in the table it can be seen that at janata college square minimum noise level was 54.5 db(a) (10.00 pm); whereas, maximum of 77.6 db(a) (10.00 am) and an average of 68.27 db(a). in case of warora naka square, minimum, maximum and average noise levels were 55.4 db(a) (10.00 pm), 88.4 db(a) (6.00 am) and 69.59 db(a) respectively. at ramnagar police station square 54.2 db(a) (12.00 pm), 79.3 db(a) (4.00 pm) and 68.79 db(a) were minimum, maximum and average noise levels respectively. the minimum noise level of 51.2 db(a) (4.00 pm), maximum of 76.1 db(a) (6.00 am) and average 67.23 db(a) were recorded at priyadarshani square. bangali camp square had minimum, maximum and average noise levels as 55.4 db(a) (10.00 pm), 83.3 db(a) (6.00 am) and 68.46 db(a) respectively. at gandhi square, it was recorded as 51.9 db(a) (9.00 pm) as minimum, 75.9 db(a) (3.00 am) as maximum and 67.17 db(a) as average noise level. at girnar square minimum, maximum and average noise levels were 52.1 db(a) (10.00 pm), 79.0 db(a) (11.00 pm) and 66.66 db(a) respectively. noise level at jatpura gate was monitored as 47.5 db(a) (4.00 am) as minimum, 77.3 db(a) (12.00 am) as maximum and average of 66.77 db(a). at bagla square minimum, maximum and average noise levels were 56.6 db(a) (12.00 pm), 76.7 db(a) (10.00 am) and 66.54 db(a) respectively. among all these sampling locations, the minimum noise level was recorded at jatpura gate 47.5 db(a) (4.00 am); whereas, warora naka square had the maximum noise level 88.4 db(a) (6.00 am). the maximum average noise level was 69.59 db(a) at warora naka square. the minimum standard deviation was at janata college square ±6.31 db(a) which indicates there was less variation in noise level during 24-hours. on the contrary, the maximum standard deviation ±8.15 db(a) was recorded at bangali camp square which indicates variation in noise level during 24-hours. peak noise hours at these traffic intersections were recorded from 10.00 am to 11.00 am in morning; whereas, from 3.00 pm to 7.00 pm in afternoon and evening. peak noise duration in morning coincides with opening of offices, schools, and commencement of other activities. afternoon and evening peak noise duration can be assigned to commercial activities, closing of offices, schools, beginning of local market activities etc. noise levels during day, night and 24-hours at traffic intersections were calculated with the help of formula developed by us epa (formula 1) is presented in table 3. © 2019 the authors. page 88 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 from the table it can be observed that, minimum daytime (ld) noise level was 79.23 db(a) at priyadarshani square and maximum at bangali camp square 84.27 db(a). at bangali camp square heavy vehicles plying on the street may have contributed to this elevated noise level. minimum noise level during nighttime (ln) was at jatpura gate 70.06 db(a); whereas, maximum 85.90 db(a) at warora naka square. at this sampling location, heavy traffic in addition to students activities from nearby education institutions may have contributed to enhanced noise level. the sound waves generated by vehicles at the intersection propagate in ambient atmosphere. out of which few sound waves strike to the bottom of the flyover and reflect back again on commuters. this phenomenon may have resulted in an increase in noise level. furthermore, no traffic signal and traffic policemen to monitor the flow of vehicles may have contributed to these observations. minimum noise level during 24-hours (ldn) was recorded at bagla square 84.34 db(a) and maximum at warora naka square 91.14 db(a). bagla square is located in the outskirt of the city with sporadic population and wide roads. socio-economic conditions of the inhabitants in the adjoining areas restrict them to use two-wheelers mostly as a result of which four wheelers number was limited. these factors may have resulted in a minimum noise level for 24 hours (ldn). maximum noise level difference [7.19 db(a)] during day (ld) and night (ldn) was recorded at ramnagar police station square. bangali camp square was identified as the most ear-splitting square during daytime; whereas, warora naka square during nighttime and 24-hours also. on comparison of noise level during daytime and nighttime with national ambient air quality standards (naaqs) with respect to noise for the commercial zone (table 4), it was observed that at all sampling locations the noise level exceed the limit during day and nighttime both. 3.2 daily noise exposure daily noise exposure at traffic intersections is presented in table 5. a commuter spends variable time at different traffic intersections; whereas, traffic policemen and women deployed at these intersections to monitor traffic flow had working hours for 8 to 10 hours per day. daily noise exposure during daytime (ld) noise level to commuters and police personnel revealed, bangali camp square and ramnagar police station square noise exposure for 0.25 hour were maximum 70 lep,d. both these intersections were one of the largest ones with heavy traffic flow throughout day and night and are the part of national highway nh 930 and state highway sh 264. in case of eight hours of traffic noise exposure, ramnagar police station square and bangali camp square had the maximum daily noise exposure of 84 lep,d. this trend remained continued for 10-hours exposure period also (85 lep,d). the minimum daily noise exposure was at gandhi square and closely followed by bagla square with daily noise exposure of 65 lep,d for 0.25 hour. both these squares were one of the smallest squares and located in a congested area with limited traffic flow devoid of heavy vehicles and traffic light. on comparison of noise exposure during daytime with occupational safety & health administration (osha) standards (table 7), it can be arrived at that there was no immediate damage risk for hearing loss on inhabitants of the city and on traffic personal deployed at traffic intersections. temporary deafness, stress, auditory fatigue, annoyance etc. can cause due to exposure to these noise levels. results of noise exposure at combinations of traffic intersections are reported in table 6. from the table, it can be observed that ramnagar police station square and bangali camp square together had daily noise exposure during daytime as 73 lep,d. in case of three traffic intersection combinations, ramnagar police station, priyadarshani square and bangali camp square had daily noise exposure during daytime as 73 lep,d which was closely followed by a combination of janata college square, warora naka square and ramnagar police station square 73 lep,d. a noise exposure analysis through a questionnaire was also carried out. for this field based survey nine traffic personnel were identified who were working for more than five years and had no health-related issues. all respondent reported irritation and disturbance due to traffic noise. heterogeneous sources such as two and four-wheelers were identified as noise source (100%); whereas, 40% as national highway and ∼ 16% as railway. maximum noise exposure time was in afternoon (53.30%) followed by morning (33.30%) and minimum during evening (13.30%). traffic noise was reported on all weekdays (86.60%); whereas, 13.30% stated sunday had more traffic noise. average noise exposure was for 12 hours a day (90%); whereas, remaining had reported it for > 12 hours. effects of noise exposure as reported by police personnel include annoyance, sleep disturbance, stress and lack of concentration. no personal protective equipment was used to protect from traffic noise exposure. furthermore, noise exposure assessment was also carried out on shopkeepers (n=25) which were exposed to traffic noise while working in their shops. all respondent reported two and four wheelers as a traffic noise source. daytime noise exposure was reported by ∼ 83%; whereas, ∼ 16% reported it during nighttime. annoyance and lack of concentration were effects reported by all subject population; whereas, sleep disturbance and stress by ∼ 66% and ∼ 53% respectively. no personal protective equipment was used by shopkeepers and awareness level regarding noise and other related standards were absent. 3.3 pearson correlation coefficient in order to quantitatively analyzed and confirm the relationship between 24-hours noise levels and other variables, pearson correlation coefficient analysis was applied to the data (table 8). there was a statistically significant positive correlation between noise level during daytime (ld) © 2019 the authors. page 89 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 and noise level during 24-hours (ldn) (p<0.01); noise level during nighttime (ln) and noise level during 24-hours (ldn) (p<0.05) and noise level during daytime (ld) and daily noise exposure (lep,d) for 0.25 hour (p<0.01). in the case of traffic volume and noise level during 24-hours (ldn), a negative correlation was observed (p<0.05). other variables such as number of roads merging at traffic intersection and the presence of traffic light were not correlated with noise level during 24-hours (ldn). noise level during daytime (ld) and nighttime (ln) were not correlated with each other. 3.4 cluster analysis figure 3a depicts four clusters for daytime (ld) noise levels. cluster 1 depicts priyadarshani square and gandhi square traffic intersections. both these intersections were of had different characteristics with reference to the presence of traffic light; however, had comparable noise levels. warora naka square and jatpura square forms the cluster 2. at both these intersections, traffic lights were not present as a result of which fluid continuous flow and pulsed continuous flow traffic typology respectively were there, which resulted in vehicles on continuous move. cluster 4, ramnagar police station square and bangali camp square, represents the noisiest intersections during daytime. at both these intersections, traffic light with roundabout was present. cluster analysis of noise levels during nighttime (ln) is depicted in figure 3b whereas, for 24-hours noise levels (ldn) in figure 3c both shows five clusters. this cluster analysis suggested that variables such as roundabout and absence or presence of traffic light had contributed to noise level at a traffic intersection at an individual level. cluster analysis of daily noise exposure at an individual traffic intersection for daytime (ld) for 0.25 hour is depicted in figure 3d. it can be seen that three clusters are there. the major cluster comprises five traffic intersections with daily noise exposure of 65 lep,d. maximum daily noise exposure was at ramnagar police station square and bangali camp square with similar traffic intersection characteristics such as a roundabout, presence of traffic light and heavy traffic volume (trucks and buses). cluster analysis of daily noise exposure for 0.25 hour at combinations of traffic intersections is presented in figure 3e. four clusters were observed for these combinations. in two clusters (six traffic intersections combinations) daily noise exposure was comparable which indicates higher daily noise exposure at a combination of traffic intersections as compared with individual traffic intersection (figure 3d). similar observations were also recorded for exposure points (job per tasks). thus, exposure at different traffic intersections may be harmful as compared with a signal traffic intersection. 3.5 correlation matrix and principal component analysis correlation matrix between day, night and 24-hours noise level is presented in table 9. from this table, it can be seen that nighttime noise level had a strong correlation (r=0.804) with 24-hours noise level as compared with daytime (r=0.611). in the principal component analysis (table 10), noise levels were grouped into two models, which account for 100% of all the data variation. in the rotated component matrix, the first principal component (variance of 55.48%) was for daytime while second principal component (variance of 44.52%) was for nighttime. the results indicate that daytime noise level contribution was higher as compared with nighttime. 3.6 scatter plot a scatter plot of noise levels and number of roads merging at traffic intersections as four (1) and three (2) is presented in figure 4a. it can be seen that, as compared with three roads merging at intersections, four roads merging had elevated noise levels. vehicular traffic from these streets contributes to noise levels at these intersections. similar observations were also recorded for the presence of traffic light (1) and absence of traffic light (2) (figure 4b). traffic light controlled intersections leads to decelerating and accelerating traffic resulted in higher noise levels than free-flowing traffic without traffic light because of higher engine noise levels and unnecessary honking. traffic volume high (1), medium (2) and light (3) contribution to noise levels are depicted in figure 4c. a clear distinction in noise level was observed between these three types of traffic volume with maximum in heavy and the minimum in light. the results reported by leong (2003) for maximum daytime and nighttime noise level of bangkok streets were comparatively lower than those obtained from the study area. as reported by djercan et al. (2015) noise intensity was in strong positive correlation with number of vehicles in traffic is in agreement with the results reported in this study. vijay et al. (2013) reported no correlation between traffic volume and observed noise levels. the results of the study were in agreement with this observation. coensel et al. (2006) found intersection type had a small influence on noise emissions. results of the study corroborate with these findings. traffic intersections with three or four roads merging into it had no significant influence on traffic noise level. according to ressel (2007) intersection with traffic light had higher noise level than roundabout and intersection with traffic light turned off. at janata college square (with traffic light) the result reported was in unity. roundabout with traffic lights at ramnagar police station square and bangali camp square had comparable results for noise levels during 24-hours with 87.30 db(a) and 88.85 db(a) respectively. due to heterogenic traffic volume and activities at intersec© 2019 the authors. page 90 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 tions like honking, ideal, gear noise, bearing noise, breaking noise, tyre-road noise and exhaust noise vijay et al. (2013) may have contributed to these elevated noise levels. in case of warora naka square traffic lights were not installed led to fluid continuous flow traffic typology. in addition, over bridge which carried heavy traffic (trucks and buses) had resulted in noisiest traffic intersection from the study area with 24-hours noise level of 91.14 db(a). as reported by dzambas et al. (2014) and nelson (1987) advantage of roundabout and intersection without traffic light was decreased in traffic noise level. these observations were recorded at gandhi square were 24-hours noise level was 84.73 db(a). this intersection was located in the heart of the city with congested streets and one-way traffic flow. in spite of these situations, 24-hours noise level (ldn) was one of the lowest from the nine intersections studied. the reason can be attributed to mini-roundabout and absence of traffic light which allows all type of traffic volume always on move with a comparatively steady velocity although with reduced speed. crossing resulted by traffic light had higher noise levels due to decelerating and accelerating traffic because of higher engine noise (dzambas et al., 2014) was observed at janata college square, priyadarshani square, and girnar square. average noise level at daytime and nighttime at ten important intersections of agartala city was 79.9 db(a) and 73.3 db(a) respectively (pal and sarkar, 2013) which was comparatively lower as compared with study area (81.55 db(a) for daytime and 77.83 db(a) for nighttime). (pal and sarkar, 2013) further reported, when vehicles were waiting for their turn to clear the intersection, drivers normally keep vehicle engine running and unnecessarily blow the horn. these observations were recorded from the study area also. tsukui and oshino (2001) report noise level close to the signalized intersection was 2.4 db(a) higher than fluid continuous traffic flow typology. this observation was in agreement with results obtained from the study area, with average 1.31 db(a) higher noise levels as compared with janata college square (traffic light intersection) versus jatpura gate and bagla square (without traffic light intersection). the roundabout induces to a 2.5 db(a) noise reduction compared to signalized intersection in an undersaturated traffic flow regime (chevallier et al., 2009). this finding was observed in the study area also. it was observed that the noise level during 24-hours between gandhi square (mini-roundabout) and janata college square (traffic light presence) was less by 1.14 db(a). active adaptation of traffic light cycles to the vehicle speed, so that a vehicle should not decelerate or accelerate in correspondence of the intersection, can lead to decrease up to 2 db(a) in the noise equivalent level (map of consolidation measures of road noise as opb art, 1998). adaptation of this method in the noisiest traffic intersection can contribute to noise level reduction. noise level was closely related to the number and composition of road traffic (manea et al., 2017). the results obtained for this study were not in agreement with these findings. street traffic noise in yazd city, iran was in the range of 70.9 db(a)-80.7 db(a) (nejadkoorki et al., 2010). results obtained from the study area for 24-hours (ldn) were slightly higher (84.34 db(a)-91.14 db(a)). a significant relationship (r2=0.5) between the average sound level and traffic flow was demonstrated (nejadkoorki et al., 2010). these findings were in agreement with the results obtained from the study area (r=-0.623, p<0.05). dwellings near the street of yazd city were likely to be exposed to unacceptable levels of noise (nejadkoorki et al., 2010). shopkeepers and police personnel from the study area had reported annoyance, lack of concentration, sleep disturbance and stress due to exposure to street traffic noise. 3.7 noise pollution control measures noise is a major factor that should be considered in the design and construction of a new transport system, as well as when improvements are to be made in existing systems (abo-qudais and alhiary, 2007). landscaping and proper engineering planning at traffic intersections will contribute to noise reduction. in addition, traffic management will be a potential option to mitigate noise levels by implementing proper vehicular movements to avoid traffic congestions and hence a reduction in noise pollution associated with it. necessary modifications in vehicular engine and silencer can contribute significantly to the reduction of noise level at the source itself. use of low noise silencer and proper horn level can attenuate noise level. removal of encroachment, creation of parking lots and proper road construction particularly near the silence zones will help to reduce noise level. furthermore, different strategies can be adapted to control noise levels at a traffic intersection includes: extending use of high occupancy vehicles for public transport, curbing motorized traffic and blowing of horn, encouraging non-motorized modes, turning off vehicle engines at traffic lights, and imparting traffic education (pal and sarkar, 2013). infrastructure up-gradation for intersections and roads, traffic flow management, avenue plantation and construction of sound barriers (balashanmugam et al., 2013) can also contribute to vehicular noise pollution reduction. 4. conclusions traffic intersections have emerged as one of the major sources contributing to noise pollution. spatio-temporal noise levels variations at these intersections were governed by factors such as traffic type, traffic light presence, traffic flow, number of roads merging at intersections and roundabouts. noise exposure to inhabitants and traffic personnel deployed at these intersections was high and correlated with daytime noise levels. noise levels at these intersections were escalating at a very fast rate and were found to be above the indian standards for the commercial area during daytime. daily noise exposure and exposure points were directly related to © 2019 the authors. page 91 of 92 gedam e et. al. indonesian journal of environmental management and sustainability, 3 (2019) 80-92 duration of noise exposure (in hours) at these intersections. although, no immediate damage risk for hearing loss on inhabitants and traffic personnel was arrived at; 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