TITLE …………………… DOI: https://doi.org/10.4316/fens.2021.017 160 Journal homepage: www.fia.usv.ro/fiajournal Journal of Faculty of Food Engineering, Ştefan cel Mare University of Suceava, Romania Volume XX, Issue 2 - 2021, pag. 160 - 164 CLEANING THE VEGETABLE OIL PRODUCTION WASTEWATER WITH ANTHRACITE Sergiy BORUK 1 , Igor WINKLER 2* , Vitaliy MISCHENCHUK 2 1 Department of Chemical Analysis, Food Safety and Testing, Institute of Biology, Chemistry and Bioresources, Yu. Fedkovych National University of Chernivtsi, 2 Kotsyubynsky St., Chernivtsi, 58012, Ukraine 2 Department of Medicinal and Pharmaceutical Chemistry, Bucovina State Medical University, 2 Teatralna Sq., Chernivtsi, 58002, Ukraine winkler@bsmu.edu.ua *Corresponding author Received 10th May 2021, accepted 28th June 2021 Abstract: The efficiency of anthracite treatment of the wastewaters formed at the sunflower oil pro- duction is investigated and discussed in comparison with other water cleaning technologies. It is found that a comparatively small amount of anthracite (10-15 % of the wastewater mass) ensures effi- cient decontamination and eliminates up to 70 % of the wastewater pollutants. This method does not require any extensive changes in the production technology and can easily be incorporated at the ex- isting production facilities. This efficiency is based on the double-nature structure of the anthracite surface, consisting of the hydrophilic and hydrophobic areas. The former ones ensure a high wettabil- ity of the adsorbent and the release of some inorganic ions that provide coagulation of the emulsified contaminants. The latter ones ensure adsorption and extraction of the dissolved and emulsified organ- ic pollutants of the wastewater. The used adsorbent can be filtered out after the extraction and then disposed of in an environmentally safe way through incineration as an admixture to the regular coal fuel. Keywords: sunflower oil production; wastewater decontamination; porous coal adsorbents; envi- ronment protection 1. Introduction Food processing is one of the leading branches of the economy in many coun- tries, including Ukraine. It produces nu- merous items with stable high market de- mand and under competitive conditions. Production of vegetable oil (mostly sun- flower) is a highly developed part of the food processing in Ukraine, with a total of 6.8 million tons of crude vegetable (mostly sunflower) oil produced in 2019 and 6.1 million tons exported to many countries in Europe and worldwide [1]. It makes Ukraine the world top exporter of these goods [2]. Hence, this branch seems very important for the national economy, and the intense functioning of the oil produc- tion facilities affects environmental condi- tions in all regions of Ukraine. The equipment used at many oil- production facilities is quite outdated, causing an increased level of environmen- tal contamination affecting air, water and soils. In the context of water contamina- tion, it should be understood that any oil production facility generates a wide range of contamination agents at all technologi- cal stages [3-6]. The suspended tissues of sunflower seeds and oil emulsions are the main water pollution agents generated at such factories. If not extracted or decon- taminated, they cause significant water pollution during the processes of their nat- ural decay. It should also be emphasized that some volatile sulfur compounds are http://www.fia.usv.ro/fiajournal mailto:winkler@bsmu.edu.ua Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XX, Issue 2 – 2021 Sergiy BORUK, Igor WINKLER, Vitaliy MISCHENCHUK, Cleaning the vegetable oil production wastewater with an- thracite, Food and Environment Safety, Volume XX, Issue 2 – 2021, pag. 160 – 164 161 formed and released into the atmosphere during these processes. It expands the dan- gerous environmental effects of the oil production industry beyond the area of wa- ter pollution. Many approaches are applied to oil pro- duction wastewater decontamination. The simplest one assumes keeping the wastewaters in an isolated pond until the natural decay processes completed, fol- lowed by their gradual discharge into local water bodies. It is an extremely inefficient method that requires a long time and does not ensure sufficient decontamination effi- ciency. Moreover, it does not control the release of environmentally dangerous vola- tile decay products into the atmosphere. Simple filtration, adsorption, electrofiltra- tion, forced oxidation and some other tech- nologies are tested and used widely to in- crease the efficiency of the oil-production wastewater treatment [4-9]. It should be emphasized that some porous wastes or by- products of the coal refinery are considered as promising adsorbents for such technolo- gies [5, 7]. Based on the nature and proper- ties of the water pollution agents present in this type of wastewater, it is expected that adsorbents with hydrophobic or mosaic surface structure should exhibit a compara- tively high pollution extraction activity. It is known that coal-like materials are among such adsorbents [5-7, 10], and therefore, their adsorption performance should be investigated to address the above mentioned issue. In this paper, the results of the oil- production wastewater treatment by an- thracite are reported. This coal material is abundant in Ukraine, comparatively inex- pensive and easily available. Besides, it is environmentally neutral and does not gen- erate any secondary water contamination if used for its treatment. Moreover, anthracite can be utilized safely through incineration as a component of the boiler feeding coal mixtures. The wastewater pollution com- ponents adsorbed on its surface are organic compounds, and they will also decompose in an environmentally safe way at such in- cineration. 2. Experimental The following types of wastewaters formed at the sunflower oil production factory in Chernivtsi, Ukraine were used in this in- vestigation: Series 1: wastewaters formed at the sun- flower seeds grinding; Series 2: wastewaters formed at the evapo- ration of sunflower oil production sludge. The “A” brand Ukrainian anthracite with an average ash content of 5.4 % and the moisture content of 2.1 % was used as an adsorbent. The material was ground, and then the 100-250 μm fraction was separat- ed using the appropriate sieves and used in the follow-up adsorption experiments. Chemical oxygen demand (COD) was de- termined by the simplified procedure [11] and used as a characteristic of wastewater contamination because the oxidizable or- ganic components are the most common pollutants of this type of wastewater [4]. Besides, the absorbance of the wastewater samples against distilled water was also measured as this parameter depends on the content of the genuinely dissolved or col- loid pollutants, not the coarse-dispersed particles. Both water quality parameters were determined for the untreated source samples and the same samples after the anthracite treatment. The treatment was performed according to the following procedure. 0.5, 1, 2, 3, 4 or 5 g of the ground anthra- cite powder were added to 25 mL of the wastewater and left for 24 h. Then the sus- pension was filtered through the paper fil- ter to separate the anthracite adsorbent from water, and the COD index was de- termined for the filtrates. A control exper- iment required for the correct COD deter- mination has been performed by the same Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XX, Issue 2 – 2021 Sergiy BORUK, Igor WINKLER, Vitaliy MISCHENCHUK, Cleaning the vegetable oil production wastewater with an- thracite, Food and Environment Safety, Volume XX, Issue 2 – 2021, pag. 160 – 164 162 procedure but with the distilled water sam- ple. 3. Results and discussion A high level of contamination was deter- mined in the initial water samples, and their COD indexes were 2450 mg O/L and 620 mg O/L for series 1 and 2 correspond- ingly. The absorbance values were com- paratively low (0.32 and 0.14, respective- ly), which means that contamination agents were mostly dissolved or formed stable emulsions. In the case of sample 1, the dis- tinct smell of hydrogen sulfide, manifest- ing decomposition of the organic pollu- tants, appeared in two weeks, while for sample 2, it appeared only in four weeks. In our opinion, this difference is caused by the lower contamination of sample 2 and the presence of some trace quantities of the technological gasoline extractant. It acts as a preservative and decelerates the natural bio-decomposition of the organics. The absorbance of both samples increases to 0.72 (sample 1) and 0.45 (sample 2), while their COD indexes decrease to 1920 and 400 mg O/L correspondingly. It can be in- terpreted as a result of the natural decom- position of the organic substances present in the wastewater samples, which forms the volatile smelling compound leaving the liquid phase. When the anthracite extractant was ap- plied, COD indexes and absorbance of the filtered samples were decreasing substan- tially because of intense capturing of the oil contaminants on its surface. The de- pendencies of these parameters on the amount of anthracite are shown in Figures 1 and 2. 0 500 1000 1500 2000 2500 0 1 2 3 4 5 Adsorbent mass, g C O D , m g O /L Fig. 1. Dependence of COD indexes on the mass of anthracite added for extraction. ♦ – sample 1; ■ – sample 2. It can be seen that even in the case of high- ly contaminated sample 1, 3-4 g of anthra- cite (10-15 wt % from the sample mass) ensure effective decontamination of the sample (elimination of around 70 % of the pollution agents), while in the case of less contaminated sample 2, this effect is reached even for 1-2 g (5-10 %) of the added anthracite. Similar results can also be seen for the absorbance of the samples (see Fig. 2). Further increase in the adsorbent mass does not result in the corresponding in- crease in the cleaning efficiency. There- fore, it can be concluded that 15 % or 10 % of anthracite added to the more or less con- taminated samples of the oil-processing wastewaters correspondingly, ensure their efficient decontamination. COD decreases fourfold in the case of more contaminated water, and it halves for less polluted water. It is a promising result that can be achieved Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XX, Issue 2 – 2021 Sergiy BORUK, Igor WINKLER, Vitaliy MISCHENCHUK, Cleaning the vegetable oil production wastewater with an- thracite, Food and Environment Safety, Volume XX, Issue 2 – 2021, pag. 160 – 164 163 without any additional investment and by using cheap and abundant material. It should also be emphasized that the used anthracite forms a slurry layer on the bot- tom of the decontamination pond, and this sediment can easily be dried through the periodical draining of the ponds followed by collecting the dried slurry and burning as a fuel admixture it in the regular coal boilers [12-14]. It should also be noted that this process is environmentally friendly and does not result in any significant in- crease in dangerous gases emissions [15]. The ash formed after such combustion is similar to the conventional coal ash and can be disposed of similarly. 0 0.05 0.1 0.15 0.2 0.25 0.3 0 1 2 3 4 5 Adsorbent mass, g A b so rb a n ce Fig. 2. Dependence of the wastewater absorbance on the mass of anthracite added for extraction. ♦ – sample 1; ■ – sample 2. Based on the registered decrease in the wastewater absorbance after its treatment with anthracite, it can be assumed that this material also provides an additional water cleaning effect by releasing the ions fol- lowed by the coagulation of the colloid pollutants present in the water. The visual turbidity of both water samples increased after the anthracite was added, and then the coagulated particles were captured by the adsorbent resulting in a decrease in the tur- bidity (see Fig. 2). This result is confirmed by an increase in the wastewater samples conductivity after their treatment with an- thracite (see Fig. 3). 0 200 400 600 800 1000 1200 0 1 2 3 4 5 Ads orbent mas s , g C o n d u c ti v it y , m S /m Fig. 3. Dependence of the wastewater conductivity on the mass of anthracite added for extraction. ♦ – sample 1; ■ – sample 2. Food and Environment Safety - Journal of Faculty of Food Engineering, Ştefan cel Mare University - Suceava Volume XX, Issue 2 – 2021 Sergiy BORUK, Igor WINKLER, Vitaliy MISCHENCHUK, Cleaning the vegetable oil production wastewater with an- thracite, Food and Environment Safety, Volume XX, Issue 2 – 2021, pag. 160 – 164 164 4. Conclusion Anthracite, as an adsorbent with the mosa- ic surface, captures and eliminates up to 70 % of the water contaminants present in the wastewaters formed at the sunflower oil production. This efficiency is based on the synergetic effect of the mineral hydrophilic and coal-like hydrophobic surface domains of the anthracite. Due to this surface struc- ture, the anthracite can be added to the wastewater, extract its pollutants, and then be separated by coagulation followed by filtration of the sediment. This technologi- cal operation can be performed periodical- ly as the wastewater treatment ponds are filled. Even in the case of the highly pol- luted sunflower grinding wastewater, 10- 15 mass % of anthracite ensure the above- mentioned decontamination efficiency. After the adsorption, the used anthracite can be utilized in an environmentally safe way through its incineration as an admix- ture to the regular coal fuel. 5. References [1]. Output of some types of industrial products in Ukraine in 2011-2019. State Statistics Service of Ukraine. http://www.ukrstat.gov.ua/operativ/operativ2006/pr /prm_ric/xls/vppv_2011_2019.xls (Accessed on March 02, 2021). [2]. V. SHYSHKIN, O. ONYSCHENKO, Present state and prospects of agricultural development of Ukraine, Management and Entrepreneurship: Trends of Development, 3(13), 72-86 (2020). DOI: 10.26661/2522-1566/2020-3/13-06 . [3]. B. MOSS, Water pollution by agriculture, Phil. Trans. R. Soc. B, 363, 659-666 (2007). DOI: 10.1098/rstb.2007.2176. [4]. S SHARMA, A. AYGUN, H. 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NYASHINA, P. A. STRIZHAK, The influence of liquid plant additives on the an- thropogenic gas emission from the combustion of coal-water slurries, Env. Pollut., 242A, 31-41 (2018). http://www.ukrstat.gov.ua/operativ/operativ2006/pr/prm_ric/xls/vppv_2011_2019.xls http://www.ukrstat.gov.ua/operativ/operativ2006/pr/prm_ric/xls/vppv_2011_2019.xls https://doi.org/10.1098/rstb.2007.2176 https://doi.org/10.1016/j.chemosphere.2020.126511 https://doi.org/10.1088/1755-1315/579/1/012042 https://doi.org/10.1088/1755-1315/579/1/012042 1. Introduction Further increase in the adsorbent mass does not result in the corresponding increase in the cleaning efficiency. Therefore, it can be concluded that 15 % or 10 % of anthracite added to the more or less contaminated samples of the oil-processing wastew... Fig. 2. Dependence of the wastewater absorbance on the mass of anthracite added for extraction. ♦ – sample 1; ■ – sample 2. Fig. 3. Dependence of the wastewater conductivity on the mass of anthracite added for extraction. ♦ – sample 1; ■ – sample 2. (1) 4. Conclusion