ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Ü‹1a26@@ÖÜ»€a@I2@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (2) 2013 Adsorption of Mono Substituted Nitro Phenols From Aqueous Solution on the Zemeej Surface at Different Temperatures Entisar E. AL-Abodi Dept. of Chemistry/College of Education For Pure Science (Ibn Al-Haitham)/ University of Baghdad Received in :27 May 2013, Accepted in: 26 August 2013 Abstract Adsorption of o-Nitrophenol (o-Nph), m- Nitrophenol (m-Nph) and p- Nitrophenol (p- Nph) on the sedimentary sand of the Tigress River which is known locally by “Zemeej” from aqueous solution at 288, 298, 308, 318 and 328 k0 . This study indicates that o-Nph and m- Nph take multi-layered S type according to Giles classification while p-Nph takes a multi- layered L type according to the same classification. The isotherms treated by Freundlich model and show a good response to this model because the heterogeneous nature of the surface. The adsorption for all materials was endothermic as shown from ΔH values and explained through the porous nature of the surface, the remaining thermodynamic functions ΔG and ΔS were also calculated at all temperatures for all adsorbents which indicate that the randomness, finally the results indicate that the orientation on NO2 group to para position acts to decrease the quantity of adsorption. Key wards: adsorption; nitrophenol; Zemeej; Freundlich isotherm 229 | Chemistry ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Ü‹1a26@@ÖÜ»€a@I2@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (2) 2013 Introduction The adsorption of phenols on agricultural soil is an important subject because the large spectrum of products, that a phenolic compound constitutes a major component forming it such as pesticides herbicides coloring materials, medical materials and even a natural product released by a living organism [1-6], its adsorption studies provide information about its stability on the soil and its distribution between soil and aqueous media. So this study is important to many fields of application in addition to the environmental field. Many researchers concerned with adsorption of various substances on the surface of soil minerals such as Kaolinite, Bentonite etc. [7-9], but there is no studies of adsorption carried on sand sediments of Tigress River that is known locally by (Zemeej) which is the best type of agricultural soil used in Baghdad. Adsorption is an important surface phenomenon usually describes the accumulation of ions, atoms or molecules on a surface [10]. It is a physicochemical process which offers great potential as a means of producing quality effluent [11]. This phenomenon of adsorption is basically due to the presence of residual forces at the surface of a liquid or a solid. Adsorption is a spontaneous process and hence is attained by a decrease in free energy change and entropy of the system [12]. The concept of adsorption equilibrium is involved deeply in the measurement and correlation of adsorption capacity, selectivity and re-generatability data. Generally, equilibrium is the constraint that limits each of these vital factors for adsorption application. However, there are many phenomena where adsorption is essential to the process such as decolorisation and dyeing of fibers, these processes occur through the adsorption process on solid surfaces [13]. Materials and Methods Instruments: 1- Visible spectrophotometer. 2- Dunboff metabolic shaking Incubater GCA/ precision Scientific. 3- Hettich Universal (D-7200), Centrifuge tubes. 4- Electronic Balance, Sartorius Lab. L420 B, +0.0001. Materials: All Nitrophenols were supplied by Fluka. (Zemeej) was obtained from local markets in Baghdad. Methodology The (Zemeej) was washed with excessive amounts of distilled water, dried at 160oC for three hours. The (Zemeej) was ground and sieved to a particle size of 320 µm. Wavelength of maximum absorbency was recorded for each Nitrophenol dissolved in aqueous media and found to be 280nm for o-Nph, 272nm for m-Nph and 318nm for p-Nph. These values were utilized for estimation of the quantity of adsorbed material. Solutions of different concentrations were prepared by serial dilution and measured at desired 𝜆𝑚𝑎𝑥 and plotted against concentration values, the calibration curve in the concentration range that falls in the region of applicability of Beer-Lambert's law was employed. Adsorption Isotherm A series of solutions of Nitrophenol (5ml) of concentrations range (5-55) mg/L at pH ≈ 8 were added to stoppered flasks containing 0.1g of (Zemeej). The flasks were shaken in a thermostatically controlled water bath at a speed of 45 rpm and 298k till equilibrium is attained (300 min). This time is sufficient for the adsorption process to reach equilibrium. After the equilibrium time elapsed, the suspensions were centrifuged at 3000 rpm for 10 min. The clear supernatants were assayed for Nitrophenol spectrophotometrically. Equilibrium 230 | Chemistry ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Ü‹1a26@@ÖÜ»€a@I2@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (2) 2013 concentrations were obtained by comparing the experimental data with the calibration curve. The quantity of Nitrophe0nol adsorbed was calculated according to the following equation (1) 𝑄𝑒 = 𝑉𝑠𝑜𝑙.(𝐶0−𝐶𝑒) 𝑚 … … … … … … … … … … … … … … … … (1) Where: 𝑄𝑒: Quantity of adsorption at equilibrium (mg/g) 𝑚 : Mass of adsorbent (g). 𝐶0 : Initial concentration (mg/L). 𝐶𝑒 : Equilibrium concentration (mg/ L). 𝑉𝑠𝑜𝑙. : Volume of solution (L). Effect of Temperature Adsorption experiment was repeated in the same manner at temperatures of 288, 308, 318 and 328 k0 to estimate the basic thermodynamic functions. Results and Discussion Figures (1,2and3) indicate the adsorption of so-Nph and m-Nph on the silica surface are multi-layered S type according to the Giles classification at all temperatures of the study while p-Nph takes a multi-layered L type according to the same classification. The multi- layered adsorption that is taking place on this surface is not strange due to the heterogeneous- porous nature of the silica surface, S type (or sigmoidal shape) means low extent of adsorption at low concentration of adsorbate then the adsorption increases rapidly with the increase of adsorbate concentration, this is because of the affinity between the adsorbent and the adsobate which is weak at the beginning but the initial amount of adsorbate that is settled on the surface of the adsorbent, it acts to provide a new active sites of adsorption which increases the adsorption extent with increase of concentration [14]. In our case, we think that the initial amounts of o-Nph and m-Nph (which carry a negative charge) that adsorbed on the silica surface (which carries a negative charge too) through hydrogen bonding among functional groups of the nitrophenols with surface polar groups letting the aromatic part of phenol directed out above the surface, with the increase of these hydrophobic aromatic groups that are covering the surface gradually become hydrophobic and this what will increase the adsorption extent rapidly, so the active sites that are covered with initial amounts of phenols will become preferred by later amounts of phenols more than empty active sites and for this reason the adsorbate molecules will aggregate as clusters on the adsorbent surface [15,16]. P-Nph isotherm takes the L type because when one of its hydrophilic groups interacts with surface polar groups through hydrogen bonding the other polar group of phenol will remain directed out the surface, therefore the surface will still hydrophilic and the decrease of the number of empty active sites that exist on the surface which will stay the more preferred positions of adsorption. The previous explanation indicates why the overall extent of adsorption of o-Nph is the largest among the other phenols. In spite of the adsorption of p- Nph takes L type of adsorption we decide to consider a Freundlich model of adsorption for all phenols because of multi-layered nature of adsorption for all phenols and the complicated nature of the surface so figures (4, 5 and 6) show the response of these adsorption isotherms to the Freundlich equation [17]: Qe=KF(Ce)^(1⁄n)……………………………… ………(2) Where KF is the Freundlich adsorption constant and its unit depends on n, n is unit-less constant. Correlation coefficient (R) that is shown in table (1) with KF and n values indicate a good response of adsorption isotherms to Freundlich model at all temperatures and for isomers of Nitrophenol. By increasing the temperature in general, all phenols showing an increase of the adsorption 231 | Chemistry ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Ü‹1a26@@ÖÜ»€a@I2@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (2) 2013 extent, this probability may be due to an endothermic absorption process taking place into pores and voids of the adsorbent in conjugation with a normal exothermic adsorption process that proceed on the adsorbent surface. To estimate the overall thermodynamic nature of the adsorption, we apply Vant-Hoff equation which is given by: ln〖K ad〗=(-ΔH)/RT+C………………..(3) Where〖K ad〗is the thermodynamic equilibrium constant that is represented by [14]: 〖K ad〗=lim┬(Ce→0)⁡〖Qe/Ce] …………………..…(4) ΔH The enthalpy change of adsorption (J/mol), or gas constant (J.mol-1. k-1) and C is the integration constant. This method of calculating equilibrium constant at zero concentration is the characteristic of multi-layer adsorption isotherms specially to those obeying Freundlich isotherm and the reason is there is no characteristic maximum point of Qe such that exists in Langmiur isotherms which the K ad is calculated on it, instead for Freundlich isotherms we plotted K ad vs. Ce then taking the intercept of the strait line and this will be the adsorption equilibrium constant at characteristic zero equilibrium concentration of the adsorbate [18]. Figure (7) shows similarity of equilibrium constant alteration with the temperature for both o- Nph and m-Nph while p-Nph shows a different behavior; in addition the Gibbs free energy of the adsorption is calculated from the equation [19]: ΔG=-RTln〖K ad〗………………………………………..(5) Also the entropy change calculated from: ΔG=ΔH-TΔS……………………………………………...(6) All the thermodynamic parameters and 〖K ad〗are listed in the table (2). As expected the adsorption processes were endothermic for all Nitophenols, o-Nph and m-Nph that have similar positive values of ΔH which support our previous proposition about contribution of absorption process in the porous and voids of the adsorbent beside the adsorption process that is taking place on the adsorbent surface, in addition for p-Nph the adsorption is less endothermic as a result to the seasons that are described above, ΔS valus are positive and change slightly with the change of temperature to each compound but the difference among the compounds is considerable, first ΔS values of o-Nph and m-Nph are close to each other and higher than that of p-Nph because the possibility of carrying out the adsorption process at the hydrophobic sites that are generated after the initial stage of adsorption, this process is not possible for p-Nph, also we expect the slight biggest value of ΔS for m-Nph than that of o- Nph is due to meta orientation of polar groups which when one of them is directed perpendicularly to adsorbent surface the other will stay free to orient horizontally with the surface in any direction. As a result for all of these reasons ΔG values are all negative as expected and decrease with the increase of temperatures for all Nitrophenols. References 1- Mauricio, M. ; Arno, C. G. and AlberTinka, J. M. (2013) ” Persistent Toxic Burdens of Halogenated Phenolic Compounds in Humans and Wildlife”, Environ. Sci. Technol. 47 (12): 6071. 2- Beckman-Sundh, U.; Binderup ,M.; Bolognesi, C.and Brimer, L. (2013) “Scientific Opinion on the toxicological evaluation of phenol”, EFSA Journal, 11(4): 3189. 3- Yaacob, N. S.; Mohamed, R.; Siti ,A. A.; Ibrahim, A. L. and Arbakariya, B. (2013) “Nutrients and culture condtions requirements for the degradation of phenol by Rhodococcus UKMP-5M “, J. of Inv. Biol. 34: 635. 4- Kundu, S. (2013) “Modeling Phenol Adsorption in Water Environment using Artificial Neural Network”, Int. Res. J. Environment Sci., 2(7): 39, 232 | Chemistry http://pubs.acs.org/action/doSearch?action=search&author=Monta%C3%B1o%2C+M&qsSearchArea=author http://pubs.acs.org/action/doSearch?action=search&author=Gutleb%2C+A+C&qsSearchArea=author http://pubs.acs.org/action/doSearch?action=search&author=Murk%2C+A+J&qsSearchArea=author ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Ü‹1a26@@ÖÜ»€a@I2@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (2) 2013 5- Sathorn, P.; Kanokon, C.; Prapawan, V.; Vichuta, C.; Leamthong, C; Wanna, I. and Orawan ,S. ( 2008). Adsorption of phenol from diluted aqueous solutions by activated carbons obtained from bagasse, oil palm shell and pericarp of rubber fruit”, Songklanakarin J. Sci. Technol. 30 (2):185 6- Moyo1, M.; Mutare, E.; Chigondo, F. and Nyamunda, B. C. (2012)” Removal of phenol from aqueous solution by adsorption on yeast, Saccharomyces Cerevisiae”, IJRRAS, 11 (3):486 7- Al-Taweel, S. S. J.;Jassim, L. S. and Trade, H. A. (2007). ” A study of Adsorption of Crystal Violet from Aqueous Solution on Kaolin”, National Journal of Chemistry, 28:642 8- Muhammad, J. I. and Muhammad, N. A. (1996)” Adsorption of dyes from aqueous solutions on activated charcoal”, Colloid Surf. A Physicochem. Eng. Aspects, 108: 39 9- Zainab, N. M.; Salah, M.A. and Rasha, A.D. (2011)” Adsorption of eosin Y dye on Iraqi clay”, Journal of Kerbala University, 9 (3):171 10- Glasstone ,S. (1962). “Physical Chemistry”, 2nd ed., Macmillan., London, 518 11- Kipling, J. J. (1965)”Adsorption from Solutions of Non-Electrolytes”, Academic Press, London, pp. 3(101-168):257-259 12- Mohammid ,Y.I. (2004)."Synthesis and characterization of zeolite – urea formaldehyde polymer complex and study of adsoption of some phenolic compounds from aqueous solution on its surface", M.Sc Thesis, Ibn–alhaitham, College of Education,University of Baghdad 13- Wagner, K. and Sehullz, S. (2001)”Adsorption of Chlorophenols and Dihydroxybenzens onto unfunctionalized polymeric resins at temperatures from 294.15k0 to 318k0”, J. Chem. Eng. Data, 46: 322 14- Giles, C. H. ; G’Silva, A. P. and Easton, I. A. (1974)” A general treatment and classification of the solute adsorption isotherm”, Jour. Of Colloid and Inter. Sci., 47(3): 766 15- Shen, Y. (2002).” Removal of phenol from water by adsorption–flocculation using organobentonite”, Water Research, 36:1107 16- Adnadjevic, B.; Lazarevic, N. and Jovanovic, J. (2009).” Thermodynamics and mechanism of Nicotine adsorption onto hydrophobic Zeolite type USY from aqueous solution”, Hem. ind., 63 (5a):571 17- Aber, S. and Haddadi, E. F. (2011)” Removal of basic yellow from aqueous solution by adsorption onto granular activated carbon using an on-line spectrophotometric analysis system”, Global NEST Journal, 13( 3):246 18- Khan, A. A. and Singh, R. P. (1987)”Adsorption thermodynamics of carbofuran on Sn(IV)arsenosilicate in H+, Na+ and Ca+2 forms”, Colloids and Surfaces, 24:33 19- Morillo, E. and Maqueda, C. (1986) ”Simultaneousadsorption of Chlordimeform and Zinc on Montmorillonite”, Soil Sci., 141:138 233 | Chemistry ÚÓ‘Ój�n€a@Î@Úœäñ€a@‚Ï‹»‹€@·rÓ:a@Âig@Ú‹©@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@Ü‹1a26@@ÖÜ»€a@I2@‚b«@H2013 Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 26 (2) 2013 Table(1) :Freundlich constants �𝑲𝒇, 𝒏�and correlation coefficient 𝑹. Table (2): Adsorption constant (Kad0) at zero concentration with thermodynamic parameters. 234 | Chemistry Fig. (1) Adsorption isotherm of o-Nph Fig. (2) Adsorption isotherm of m-Nph Fig. (3) Adsorption isotherm of p-Nph 0 5 10 15 20 0 10 20 30 40 50 Q e( m g/ g) Ce(mg/L) o.Nph ۲۸۸ ۲۹۸ ۳۰۸ ۳۱۸ ۳۲۸ 0 2 4 6 8 10 12 14 0 10 20 30 40 Q e( m g/ g) Ce(mg/L) m.Nph ۲۸۸ ۲۹۸ ۳۰۸ ۳۱۸ ۳۲۸ 0 2 4 6 8 10 12 14 0 10 20 30 40 Q e( m g/ g) Ce(mg/L) p.Nph ۲۸۸ ۲۹۸ ۳۰۸ ۳۱۸ ۳۲۸ 235 | Chemistry Fig. (4) Linearized Freundlich curves for o-Nph Fig. (5) Linearized Freundlich curves for m-Nph Fig. (6) Linearized Freundlich curves for p-Nph 0 1 2 3 4 0 1 2 3 4 ln (Q e) ln(Ce) F.I. oNph ۲۸۸ ۲۹۸ ۳۰۸ ۳۱۸ ۳۲۸ -2 -1 0 1 2 3 0 0.5 1 1.5 2 2.5 3 3.5 4 ln (Q e) ln(Ce) F.I.mNph ۲۸۸ ۲۹۸ ۳۰۸ ۳۱۸ ۳۲۸ -0.5 0 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 3 3.5 4 ln (Q e) ln(Ce) F.I.pNph ۲۸۸ ۲۹۸ ۳۰۸ ۳۱۸ ۳۲۸ 236 | Chemistry Fig. (7) Plot of ln(Kad0 ) vs. 1/T y = -3681.4x + 18.145 R² = 0.9868 y = -3924.6x + 18.911 R² = 0.9101 y = -1133.7x + 9.6626 R² = 0.9517 5 5.5 6 6.5 7 7.5 0.003 0.0031 0.0032 0.0033 0.0034 0.0035 ln (K ad 0 ) 1/T oNph mNph pNph 237 | Chemistry امتزاز النیترو فینوالت احادیة التعویض من محلولھا المائي على سطح الزمیج في درجات حرارة مختلفة انتصار علیوي العبودي جامعة بغداد /الكیمیاء / كلیة التربیة للعلوم الصرفة (ابن الھیثم) علوم قسم 2013آب 26، قبل البحث في : 2013آیار 27استلم البحث في : الخالصة p- Nitrophenolو m- Nitrophenol (m-Nph) و o-Nitrophenol (o-Nph) تم اجراء دراسة امتزاز (p-Nph) (328 ,318 ,308 ,298 ,288)من محلیلھا المائیة على سطح الزمیج في درجات حرارة k0 و قد بینت ھذه Lالنمط p-Nphبینما یاخذ Gilesمتعدد الطبقات حسب تصنیف Sتاخذ النمط m-Nphو o-Nphالدراسة ان امتزاز المواد عند درجات الحرارة المدروسة وفق نموذج متعدد الطبقات طبقا لنفس التصنیف، عولجت ایزوثیرمات االمتزاز لھذه Freundlich لالمتزاز نظرا لطبیعة السطح غیر المتجانسة و بینت ھذه الحسابات ان ایزوثرمات االمتزاز ھذه تستجیب ة و . بینت ھذه الدراسة ان االمتزاز كان من النوع الماص للحرارة لكافة المواد الممتز Freundlichبصورة جیدة لنموذج المحسوبة وقد فسرت ھذه النتیجة استنادا الى الطبیعة المسامیة للسطح الماز، باالضافة الى ذلك تم ΔHذلك من خالل قیم عند جمیع درجات الحرارة حیث یتضح ان الترتیب العشوائي للمواد الممتزة ΔSو ΔGحساب قیم الدوال الثرمودینامیكیة في المحلول المائي. واخیرا من النتائج التي تم التوصل الیھا ایضا ان وجود مجموعة على السطح اكبر من ذلك الذي تمتلكھ النایترو یعمل على تقلیل كمیة االمتزاز في ھذا النظام. : زمیج، االمتزاز، نیتروفینول، ایزوثیرم فرندلیشالكلمات المفتاحیة 238 | Chemistry