The removal of formaldehyde as a toxic substance from aqueous solutions is of particular importance. In this research, a sequencing batch rotating-bed bioreactor (SBRB) was used on a laboratory scale for biodegradation of formaldehyde from synthetic wastewater. The reactor was made of plexiglas with a cylindrical shape. Kaldnes media were placed in a rotating cylindrical basket in the reactor. The effects of formaldehyde concentration (500–1500 mg/L), hydraulic retention time (HRT) (8, 15, 24 hours), and injection of hydrogen peroxide (0.1-0.5 mM) on the performance of the reactor were investigated. The results showed that in the SBRB, at an HRT of 24 hours and an inlet formaldehyde concentration of 1000 mg/L, the removal efficiencies of formaldehyde and chemical oxygen demand (COD) were 99.2% and 92%, respectively, while without rotating the bed, the removal efficiency of formaldehyde and COD was found to be 95% and 83%, respectively. By adding hydrogen peroxide at a concentration of 0.3 mM and operation of the SBRB with an HRT of 8 hours and an inlet formaldehyde concentration of 1000 mg/L, an improvement in the removal efficiency of formaldehyde and COD (4% and 22%, respectively) was observed. Accordingly, SBRB stimulation with hydrogen peroxide could be considered as a high-performance process for the removal of formaldehyde and corresponding COD at a short HRT.
{"title":"Enhanced Biodegradation of Formaldehyde Using Aerobic Sequencing Batch Rotating Bed Bioreactor With and Without Stimulation by Hydrogen Peroxide","authors":"A. Yazdanbakhsh, M. Sadani, Mohammad Golaki","doi":"10.34172/ajehe.2022.06","DOIUrl":"https://doi.org/10.34172/ajehe.2022.06","url":null,"abstract":"The removal of formaldehyde as a toxic substance from aqueous solutions is of particular importance. In this research, a sequencing batch rotating-bed bioreactor (SBRB) was used on a laboratory scale for biodegradation of formaldehyde from synthetic wastewater. The reactor was made of plexiglas with a cylindrical shape. Kaldnes media were placed in a rotating cylindrical basket in the reactor. The effects of formaldehyde concentration (500–1500 mg/L), hydraulic retention time (HRT) (8, 15, 24 hours), and injection of hydrogen peroxide (0.1-0.5 mM) on the performance of the reactor were investigated. The results showed that in the SBRB, at an HRT of 24 hours and an inlet formaldehyde concentration of 1000 mg/L, the removal efficiencies of formaldehyde and chemical oxygen demand (COD) were 99.2% and 92%, respectively, while without rotating the bed, the removal efficiency of formaldehyde and COD was found to be 95% and 83%, respectively. By adding hydrogen peroxide at a concentration of 0.3 mM and operation of the SBRB with an HRT of 8 hours and an inlet formaldehyde concentration of 1000 mg/L, an improvement in the removal efficiency of formaldehyde and COD (4% and 22%, respectively) was observed. Accordingly, SBRB stimulation with hydrogen peroxide could be considered as a high-performance process for the removal of formaldehyde and corresponding COD at a short HRT.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44457005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Given the variable nature of industrial wastewaters, the appropriate operation of an industrial wastewater treatment plant (WWTP) is a prerequisite for keeping process stability at ideal conditions. In this respect, an artificial neural network (ANN) can be a powerful device for the prediction of treatment performance. This study assessed some qualitative parameters of industrial wastewater (Amol Industrial Estate) during a one-year operating period. The wastewater treatment process consisted of an equalization tank, up-flow anaerobic fixed bed (UAFB) bioreactor, activated sludge tank, sedimentation tank, and chlorination basin. The ANN was utilized to estimate the system efficiency of the UAFB process. The outcomes demonstrated an extraordinary arrangement between the real and simulated data (R2>0.8). This model supplied a proper device for forecasting the implementation of WWTPs. Continuous checking elements could be used for the simulation of wastewater specifications.
{"title":"Simulation of an Industrial Wastewater Treatment Plant by Up-flow Anaerobic Fixed Bed Bioreactor Based on an Artificial Neural Network","authors":"Kobra Verijkazemi, R. Jalilzadeh Yengejeh","doi":"10.34172/ajehe.2022.01","DOIUrl":"https://doi.org/10.34172/ajehe.2022.01","url":null,"abstract":"Given the variable nature of industrial wastewaters, the appropriate operation of an industrial wastewater treatment plant (WWTP) is a prerequisite for keeping process stability at ideal conditions. In this respect, an artificial neural network (ANN) can be a powerful device for the prediction of treatment performance. This study assessed some qualitative parameters of industrial wastewater (Amol Industrial Estate) during a one-year operating period. The wastewater treatment process consisted of an equalization tank, up-flow anaerobic fixed bed (UAFB) bioreactor, activated sludge tank, sedimentation tank, and chlorination basin. The ANN was utilized to estimate the system efficiency of the UAFB process. The outcomes demonstrated an extraordinary arrangement between the real and simulated data (R2>0.8). This model supplied a proper device for forecasting the implementation of WWTPs. Continuous checking elements could be used for the simulation of wastewater specifications.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47812307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Asgari, A. Seid-mohammadi, Ramin Khoshniyat, Esmaeil Ghahramani, Hana Shabrandi
Metallic coagulants have been used for more coagulation and flocculation of flocs in many wastewater treatment plants (WWTPs) in all parts of the world. The integration of different methods to improve the wastewater treatment process has been considered in recent years. In this case-control study, the effects of four main coagulants (ferric chloride, ferric sulfide, alum, and poly-aluminum chloride) on sludge volume index (SVI) with and without exposure of static magnetic fields (SMFs) have been investigated. Both methods significantly reduced SVI (mL/g), but the combination of SMFs and coagulants was more effective. Ferric chloride could control bulking or reduce SVI to less than 150 mL/g at concentrations of 0.0625 to 2 g/L when the SMFs intensity of 15 mT was used. The control of bulking in other coagulants happened when SMFs were added to coagulants at 0.0625-0.125 g/L concentration of coagulants (P<0.05). With the application of SMFs, the highest reduction of SVI belonged to ferric sulfide (43.60%), followed by ferric chloride (18.40%), poly-aluminum chloride (PACl) (20.19%), and alum (19.80%). Without the application of SMFs, the highest reduction of SVI belonged to ferric chloride (38.36%), followed by alum (34.94%), PACl (25.43%), and ferric sulfide (6.69%).
{"title":"Bulking Control in Complete-Mixed Activated Sludge Process Using Combination of Metallic Coagulants and Static Magnetic Fields","authors":"G. Asgari, A. Seid-mohammadi, Ramin Khoshniyat, Esmaeil Ghahramani, Hana Shabrandi","doi":"10.34172/ajehe.2022.02","DOIUrl":"https://doi.org/10.34172/ajehe.2022.02","url":null,"abstract":"Metallic coagulants have been used for more coagulation and flocculation of flocs in many wastewater treatment plants (WWTPs) in all parts of the world. The integration of different methods to improve the wastewater treatment process has been considered in recent years. In this case-control study, the effects of four main coagulants (ferric chloride, ferric sulfide, alum, and poly-aluminum chloride) on sludge volume index (SVI) with and without exposure of static magnetic fields (SMFs) have been investigated. Both methods significantly reduced SVI (mL/g), but the combination of SMFs and coagulants was more effective. Ferric chloride could control bulking or reduce SVI to less than 150 mL/g at concentrations of 0.0625 to 2 g/L when the SMFs intensity of 15 mT was used. The control of bulking in other coagulants happened when SMFs were added to coagulants at 0.0625-0.125 g/L concentration of coagulants (P<0.05). With the application of SMFs, the highest reduction of SVI belonged to ferric sulfide (43.60%), followed by ferric chloride (18.40%), poly-aluminum chloride (PACl) (20.19%), and alum (19.80%). Without the application of SMFs, the highest reduction of SVI belonged to ferric chloride (38.36%), followed by alum (34.94%), PACl (25.43%), and ferric sulfide (6.69%).","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48420103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fish consumption has been considerably increased in Iran recently. On the other hand, the increase in aquatic ecosystem pollution can cause the accumulation of heavy metals in aquatic animals – the fish, in particular. Therefore, measuring the amount of heavy metals in fish is of great importance for consumers’ health. This study aimed to measure the amount of heavy metals (nickel, chromium, and cobalt) in wild and farmed carps (Cyprinus carpio) by using an ICP device. In this cross-sectional study which was performed in Hamadan province in 2018, 40 carp samples (20 wild carp samples and 20 farmed ones) were randomly collected from Anouch and Shirinsoo dams and from breeding centers of the province and, after completing the digestion phase, the amount of heavy metals in the samples were measured using the ICP device. The study results showed that the amounts of nickel metal in wild and farmed carps were equal to 0.108±0.086 and 0.102±0.108 mg/kg dry weight, respectively; and the amounts of chromium in wild and farmed fish samples were 0.348±0.396 and 0.136±0.074 mg/kg dry weight in muscle tissue, respectively. Cobalt metal was not observed in wild and cultured samples. According to the results from the statistical analysis, no significant difference was detected between wild and farmed fishes regarding contamination with nickel metal. However, a difference was found between wild and farmed fishes (P<0.05) regarding chromium. Taking into account the higher amount of nickel and chromium metals in the wild carp samples compared to the farmed ones, it was recommended that necessary measures be taken to control the sources responsible for polluting the aquatic environment and to prevent the penetration of industrial effluents and other polluting factors into the dams of Hamedan province in order for avoiding the increase in the amount of heavy metals in the province’s water sources.
{"title":"Measurement of Heavy Metals (Nickel, Chromium, and Cobalt) in Wild and Farmed Carps (Cyprinus carpio) of Hamadan Province","authors":"Mohammad Moghadasi, A. Heshmati, A. Vahidinia","doi":"10.34172/ajehe.2021.12","DOIUrl":"https://doi.org/10.34172/ajehe.2021.12","url":null,"abstract":"Fish consumption has been considerably increased in Iran recently. On the other hand, the increase in aquatic ecosystem pollution can cause the accumulation of heavy metals in aquatic animals – the fish, in particular. Therefore, measuring the amount of heavy metals in fish is of great importance for consumers’ health. This study aimed to measure the amount of heavy metals (nickel, chromium, and cobalt) in wild and farmed carps (Cyprinus carpio) by using an ICP device. In this cross-sectional study which was performed in Hamadan province in 2018, 40 carp samples (20 wild carp samples and 20 farmed ones) were randomly collected from Anouch and Shirinsoo dams and from breeding centers of the province and, after completing the digestion phase, the amount of heavy metals in the samples were measured using the ICP device. The study results showed that the amounts of nickel metal in wild and farmed carps were equal to 0.108±0.086 and 0.102±0.108 mg/kg dry weight, respectively; and the amounts of chromium in wild and farmed fish samples were 0.348±0.396 and 0.136±0.074 mg/kg dry weight in muscle tissue, respectively. Cobalt metal was not observed in wild and cultured samples. According to the results from the statistical analysis, no significant difference was detected between wild and farmed fishes regarding contamination with nickel metal. However, a difference was found between wild and farmed fishes (P<0.05) regarding chromium. Taking into account the higher amount of nickel and chromium metals in the wild carp samples compared to the farmed ones, it was recommended that necessary measures be taken to control the sources responsible for polluting the aquatic environment and to prevent the penetration of industrial effluents and other polluting factors into the dams of Hamedan province in order for avoiding the increase in the amount of heavy metals in the province’s water sources.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48362357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nowadays, the entry of heavy metals entry into aqueous environments has jeopardized the health of human societies. The experiment was conducted in discontinuous conditions, and the study focused on examining the effect of five parameters including initial concentration, temperature, contact time, pH, and adsorbent dose on the adsorption of Cu heavy metals. In addition, the two-parameter models of Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich were studied and compared to evaluate isothermal absorption. The highest correlation coefficients were obtained for Freundlich (0.969) and Dubinin-Radushkevich (0.9603) models. Finally, thermodynamic parameters such as enthalpy and entropy changes and Gibbs-free energy were calculated as well. The pH parameters, adsorption dose, contact time, temperature, and initial Cu concentrations in the discontinuous system had a statistically significant effect on the adsorption process. The results showed that the maximum efficiency of Cu adsorption by Lignocellulose nanofiber (LCNF) occurred at the pH of 6, contact time of 60 minutes, the ambient temperature of 25°C, and adsorption dose of 0.2 g. In the case of adsorption kinetics, the pseudo-second order model and intra-particle diffusion had more fitness with the experimental data indicating a chemical equilibrium between the adsorbate and the absorbent. Thermodynamic studies demonstrated that the process (negative ΔG) is spontaneous (negative ΔG), endothermic (negative ΔH), and non-random (positive ΔS). Thus, LCNF can be used as an effective adsorbent in the removal of metals by having an extremely high surface area.
{"title":"Lignocellulose Nanofiber Media for the Enhanced Removal of Copper From Aqueous Solutions","authors":"S. Rastegar, Mansoor Ghaffari, H. Hoseini","doi":"10.34172/ajehe.2021.09","DOIUrl":"https://doi.org/10.34172/ajehe.2021.09","url":null,"abstract":"Nowadays, the entry of heavy metals entry into aqueous environments has jeopardized the health of human societies. The experiment was conducted in discontinuous conditions, and the study focused on examining the effect of five parameters including initial concentration, temperature, contact time, pH, and adsorbent dose on the adsorption of Cu heavy metals. In addition, the two-parameter models of Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich were studied and compared to evaluate isothermal absorption. The highest correlation coefficients were obtained for Freundlich (0.969) and Dubinin-Radushkevich (0.9603) models. Finally, thermodynamic parameters such as enthalpy and entropy changes and Gibbs-free energy were calculated as well. The pH parameters, adsorption dose, contact time, temperature, and initial Cu concentrations in the discontinuous system had a statistically significant effect on the adsorption process. The results showed that the maximum efficiency of Cu adsorption by Lignocellulose nanofiber (LCNF) occurred at the pH of 6, contact time of 60 minutes, the ambient temperature of 25°C, and adsorption dose of 0.2 g. In the case of adsorption kinetics, the pseudo-second order model and intra-particle diffusion had more fitness with the experimental data indicating a chemical equilibrium between the adsorbate and the absorbent. Thermodynamic studies demonstrated that the process (negative ΔG) is spontaneous (negative ΔG), endothermic (negative ΔH), and non-random (positive ΔS). Thus, LCNF can be used as an effective adsorbent in the removal of metals by having an extremely high surface area.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45369939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study integrated the rapid impact assessment matrix (RIAM) analysis and the mathematical sustainability modeling to evaluate disposal options so as to find the most appropriate and practical unmitigated option for the main waste disposal site in Tehran, Iran. RIAM analysis was used to assess environmental impacts of five potential disposal options followed by determination of sustainability for each option. RIAM analysis results indicated that option 5 (i.e., composting) had the least negative cumulative impacts on the environmental score value of -481 among the studied options. Incineration of wastes, option 4, was found to be the least favorable option mainly due to the high relevant costs and emission of air pollutants. Option 3, sanitary landfilling, was found to have fewer negative impacts compared to the options 1 (open dumping), 2 (land burial), and 4. It was also found that none of the examined options were sustainable in unmitigated state; however, results indicated that option 5 was the most favorable one in terms of sustainability with an obtained sustainable value of -0.126, which was the lowest value of unsustainability found in the present study. Calculated values of environment for the evaluated options in unmitigated state were not sufficient enough to compensate for the corresponding values of human needs and interests. Finally, option 5 followed by option 3 were suggested as alternative disposal approaches for the current methods in unmitigated state to reduce negative environmental impacts of waste disposal.
{"title":"Insight into an Integrated Evaluation of Unmitigated Disposal Options for the Largest Waste Disposal Site in Tehran Using Rapid Impact and Sustainability Assessment Method","authors":"Ali Daryabeigi Zand, Maryam Rabiee Abyaneh","doi":"10.34172/ajehe.2021.10","DOIUrl":"https://doi.org/10.34172/ajehe.2021.10","url":null,"abstract":"This study integrated the rapid impact assessment matrix (RIAM) analysis and the mathematical sustainability modeling to evaluate disposal options so as to find the most appropriate and practical unmitigated option for the main waste disposal site in Tehran, Iran. RIAM analysis was used to assess environmental impacts of five potential disposal options followed by determination of sustainability for each option. RIAM analysis results indicated that option 5 (i.e., composting) had the least negative cumulative impacts on the environmental score value of -481 among the studied options. Incineration of wastes, option 4, was found to be the least favorable option mainly due to the high relevant costs and emission of air pollutants. Option 3, sanitary landfilling, was found to have fewer negative impacts compared to the options 1 (open dumping), 2 (land burial), and 4. It was also found that none of the examined options were sustainable in unmitigated state; however, results indicated that option 5 was the most favorable one in terms of sustainability with an obtained sustainable value of -0.126, which was the lowest value of unsustainability found in the present study. Calculated values of environment for the evaluated options in unmitigated state were not sufficient enough to compensate for the corresponding values of human needs and interests. Finally, option 5 followed by option 3 were suggested as alternative disposal approaches for the current methods in unmitigated state to reduce negative environmental impacts of waste disposal.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43747615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammed Y. Saleh, H. Arslan, Zelal Isik, M. Yalvaç, N. Dizge
Membrane technology is a green technology, but it still faces a pressing problem related to the effect of fabrication materials on the environment. The plant Verbascum thapsus L (VTL) was utilized as a biomembrane to reduce chemicals. In this study, VTL was successfully utilized as a membrane for activated sludge separation. The membrane was characterized via scanning electron microscopy (SEM)-EDX, Fourier transform infrared (FTIR), and contact angle measurement. Additionally, the effects of pressures on the fluxes and the rejection ability were studied. The permeability of the bio-based membrane reached 581 L/m2 .h.bar. The VTL membrane was examined for the removal of chemical oxygen demand (COD), protein, and carbohydrate. Accordingly, the maximum COD removal was obtained at a transmembrane pressure of 2.5 bar and reached up to 57%. The protein and carbohydrates rejections raised from 80% and 84% at 0.5 bar to 90% and 98% at 2.5 bar, respectively. The total resistance increased from 87% at a pressure of 0.5 bar to 96% at 2.5 bar. The flux recovery ratio (FRR) for the membrane at working pressures (0.5-2.5 bar) was 96% for 0.5 bar and 70% for 2.5 bar. The physical cleaning showed a flux recovery after three operation cycles. At the end of the filtration experiments, the pressure variation along streamlines over the membrane cross-section was simulated. As a result of this study, the use of a naturally-derived membrane is considered a green technology. The plant-based membrane reduces the use of non-green chemicals. Moreover, VTL has no commercial value and is recognized as an invasive plant species. All of the previous issues made the study worthwhile.
{"title":"The Use of Verbascum Thapsus L as a Biomembrane for Activated Sludge Filtration","authors":"Muhammed Y. Saleh, H. Arslan, Zelal Isik, M. Yalvaç, N. Dizge","doi":"10.34172/ajehe.2021.13","DOIUrl":"https://doi.org/10.34172/ajehe.2021.13","url":null,"abstract":"Membrane technology is a green technology, but it still faces a pressing problem related to the effect of fabrication materials on the environment. The plant Verbascum thapsus L (VTL) was utilized as a biomembrane to reduce chemicals. In this study, VTL was successfully utilized as a membrane for activated sludge separation. The membrane was characterized via scanning electron microscopy (SEM)-EDX, Fourier transform infrared (FTIR), and contact angle measurement. Additionally, the effects of pressures on the fluxes and the rejection ability were studied. The permeability of the bio-based membrane reached 581 L/m2 .h.bar. The VTL membrane was examined for the removal of chemical oxygen demand (COD), protein, and carbohydrate. Accordingly, the maximum COD removal was obtained at a transmembrane pressure of 2.5 bar and reached up to 57%. The protein and carbohydrates rejections raised from 80% and 84% at 0.5 bar to 90% and 98% at 2.5 bar, respectively. The total resistance increased from 87% at a pressure of 0.5 bar to 96% at 2.5 bar. The flux recovery ratio (FRR) for the membrane at working pressures (0.5-2.5 bar) was 96% for 0.5 bar and 70% for 2.5 bar. The physical cleaning showed a flux recovery after three operation cycles. At the end of the filtration experiments, the pressure variation along streamlines over the membrane cross-section was simulated. As a result of this study, the use of a naturally-derived membrane is considered a green technology. The plant-based membrane reduces the use of non-green chemicals. Moreover, VTL has no commercial value and is recognized as an invasive plant species. All of the previous issues made the study worthwhile.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46469799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The current work investigated the optimization of synthetic textile wastewater (STW) containing methyl orange, crystal violet, and neutral red reactive dye degradation on manganese dioxide coated on graphite electrode using the Box-Behnken design (BBD). Carbon coated by manganese oxide (C/ MnO2 ) electrode was prepared by the sol-gel method. Graphite substrates were obtained from spent lithium-ion batteries for recycling and reducing the price of the electrode material in electrochemical processes. C/MnO2 was used as anode and cathode in an electrochemical cell during experiments. In addition, BBD was applied to design the experiments and find the optimal conditions for the degradation of STW. From the proposed model, the rate of the removal efficiency of chemical oxygen demand (COD) reached 83.63% with the optimum conditions (6.989 hours, concentration of 1.5 g/L NaCl, and current density of 50 mA/cm2 ). Based on the obtained optimum values, the specific energy consumption was around 30.359 kWh (kg COD)-1. Furthermore, the C/MnO2 electrode was characterized by Raman spectroscopy, and MnO2 films were prepared from the sol-gel process and deposited on graphite. Thus, using graphite coated with manganese dioxide, indirect anodic oxidation (IAO) can be efficient for the removal of the organic matter from the real textile dye bath.
{"title":"Electrochemical Degradation of Synthetic Textile Wastewater by C/MnO2 Electrode Assessed by Surface Response Methodology","authors":"Romuald Teguia Doumbi, G. B. Noumi, Tinda Domga","doi":"10.34172/ajehe.2021.15","DOIUrl":"https://doi.org/10.34172/ajehe.2021.15","url":null,"abstract":"The current work investigated the optimization of synthetic textile wastewater (STW) containing methyl orange, crystal violet, and neutral red reactive dye degradation on manganese dioxide coated on graphite electrode using the Box-Behnken design (BBD). Carbon coated by manganese oxide (C/ MnO2 ) electrode was prepared by the sol-gel method. Graphite substrates were obtained from spent lithium-ion batteries for recycling and reducing the price of the electrode material in electrochemical processes. C/MnO2 was used as anode and cathode in an electrochemical cell during experiments. In addition, BBD was applied to design the experiments and find the optimal conditions for the degradation of STW. From the proposed model, the rate of the removal efficiency of chemical oxygen demand (COD) reached 83.63% with the optimum conditions (6.989 hours, concentration of 1.5 g/L NaCl, and current density of 50 mA/cm2 ). Based on the obtained optimum values, the specific energy consumption was around 30.359 kWh (kg COD)-1. Furthermore, the C/MnO2 electrode was characterized by Raman spectroscopy, and MnO2 films were prepared from the sol-gel process and deposited on graphite. Thus, using graphite coated with manganese dioxide, indirect anodic oxidation (IAO) can be efficient for the removal of the organic matter from the real textile dye bath.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41586278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Municipal wastewater is one of the largest volumes of wastewater which contains various organic compounds from proteins and fats to carbohydrates and nucleic acids. Municipal wastewater of Behshahr city (Mazandaran, Iran) was evaluated using aluminum sulfate and iron chloride as chemical coagulants and pectin and sodium alginate as natural ones. Biological oxygen demand was investigated at different temperatures and coagulant concentrations. The fraction of full factorial statistical method and Qualitek-4 software were applied for designing experiments and analyzing the results to determine the optimal conditions for achieving the highest reduction in wastewater organic load and biological oxygen demand. In the case of biological oxygen demand, the optimal condition was achieved at 25°C, using 1, 0.02, 1.5 and 1 g/L of aluminum sulfate, sodium alginate, iron chloride and pectin, respectively. Under the optimal condition, the percentage of biological oxygen demand reduction was equal to 34.5%. Maximum BOD removal of 40.9% was obtained at 25°C using aluminum sulfate, sodium alginate, iron chloride, and pectin at concentrations of 0.6, 0.02, 1.5, and 6 g/L, respectively. The contribution of aluminum sulfate, sodium alginate, iron chloride, and pectin concentration in biological oxygen demand removal of the studied wastewater was 3.8%, 22.4%, 16.3%, and 14.4%, respectively. Coagulation temperature and aluminum sulfate concentration with approximately 42.7% and 3.8% contribution values were determined as the most and the least effective factors in biological oxygen demand reduction.
{"title":"Evaluation of Natural and Chemical Coagulants Performance in Treatment of Municipal Wastewater of Behshahr City","authors":"Sakineh Tabaki, F. Ardestani","doi":"10.34172/ajehe.2021.14","DOIUrl":"https://doi.org/10.34172/ajehe.2021.14","url":null,"abstract":"Municipal wastewater is one of the largest volumes of wastewater which contains various organic compounds from proteins and fats to carbohydrates and nucleic acids. Municipal wastewater of Behshahr city (Mazandaran, Iran) was evaluated using aluminum sulfate and iron chloride as chemical coagulants and pectin and sodium alginate as natural ones. Biological oxygen demand was investigated at different temperatures and coagulant concentrations. The fraction of full factorial statistical method and Qualitek-4 software were applied for designing experiments and analyzing the results to determine the optimal conditions for achieving the highest reduction in wastewater organic load and biological oxygen demand. In the case of biological oxygen demand, the optimal condition was achieved at 25°C, using 1, 0.02, 1.5 and 1 g/L of aluminum sulfate, sodium alginate, iron chloride and pectin, respectively. Under the optimal condition, the percentage of biological oxygen demand reduction was equal to 34.5%. Maximum BOD removal of 40.9% was obtained at 25°C using aluminum sulfate, sodium alginate, iron chloride, and pectin at concentrations of 0.6, 0.02, 1.5, and 6 g/L, respectively. The contribution of aluminum sulfate, sodium alginate, iron chloride, and pectin concentration in biological oxygen demand removal of the studied wastewater was 3.8%, 22.4%, 16.3%, and 14.4%, respectively. Coagulation temperature and aluminum sulfate concentration with approximately 42.7% and 3.8% contribution values were determined as the most and the least effective factors in biological oxygen demand reduction.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46901393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Jorfi, F. Rahim, A. Rahmani, N. Jaafarzadeh, Z. Ghaedrahmat, H. Almasi, A. Zahedi
Several recent studies have focused on leaching pesticides from agricultural soils into surface and groundwater resources during irrigation. As a result, information about herbicide residues in water was necessary for conserving related resources. This study provided an overview of monitoring herbicides in water resources worldwide. In this scoping review, five databases were searched for publications (1990 to April 2021), including Scopus, PubMed/Medline, Cochrane library, Embase, and Web of Science. Among the 394 identified articles, 17 papers were selected for inclusion. Most of these studies have been conducted in regions with low herbicide concentrations, including Spain, Greece, Canada, Brazil, Hungary, Malawi, Portugal, Lesotho, Germany, Serbia, and the USA. The high-level alachlor, metolachlor, atrazine, metribuzin, and simazine herbicides in groundwater were detected in Portugal (0.4-13μg/L). An overview of studies demonstrated that herbicides are widely used in water resources, and surface waters are more contaminated than groundwaters.
最近的一些研究集中在灌溉过程中农药从农业土壤中渗入地表水和地下水资源。因此，有关水中除草剂残留的信息对保护相关资源是必要的。本研究综述了全球水资源除草剂监测的概况。在这篇范围综述中，检索了五个数据库的出版物(1990年至2021年4月)，包括Scopus、PubMed/Medline、Cochrane library、Embase和Web of Science。在394篇确定的文章中，17篇入选。这些研究大多是在除草剂浓度较低的地区进行的，包括西班牙、希腊、加拿大、巴西、匈牙利、马拉维、葡萄牙、莱索托、德国、塞尔维亚和美国。葡萄牙地下水中检测到高浓度的甲草胺、甲草胺、阿特拉津、甲曲霉嗪、辛曲霉嗪等除草剂(0.4 ~ 13μg/L)。研究综述表明，除草剂在水资源中被广泛使用，地表水比地下水污染更严重。
{"title":"Herbicide Residues in Water Resources: A Scoping Review","authors":"S. Jorfi, F. Rahim, A. Rahmani, N. Jaafarzadeh, Z. Ghaedrahmat, H. Almasi, A. Zahedi","doi":"10.34172/ajehe.2021.16","DOIUrl":"https://doi.org/10.34172/ajehe.2021.16","url":null,"abstract":"Several recent studies have focused on leaching pesticides from agricultural soils into surface and groundwater resources during irrigation. As a result, information about herbicide residues in water was necessary for conserving related resources. This study provided an overview of monitoring herbicides in water resources worldwide. In this scoping review, five databases were searched for publications (1990 to April 2021), including Scopus, PubMed/Medline, Cochrane library, Embase, and Web of Science. Among the 394 identified articles, 17 papers were selected for inclusion. Most of these studies have been conducted in regions with low herbicide concentrations, including Spain, Greece, Canada, Brazil, Hungary, Malawi, Portugal, Lesotho, Germany, Serbia, and the USA. The high-level alachlor, metolachlor, atrazine, metribuzin, and simazine herbicides in groundwater were detected in Portugal (0.4-13μg/L). An overview of studies demonstrated that herbicides are widely used in water resources, and surface waters are more contaminated than groundwaters.","PeriodicalId":8672,"journal":{"name":"Avicenna Journal of Environmental Health Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47515458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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