Zohreh Alimohamadi, Habibollah Younesi, N. Bahramifar
This study investigated the effect of temperature, different concentrations of sodium carbonate,and the dose of organic solvent on the desorption of Reactive Red 198 dye from dye-saturated activated carbon using batch and continuous systems. The results of the batch desorption test showed 60% acetone in water as the optimum amount. However, when the concentration of sodium carbonate was raised, the dye desorption percentage increased from 26% to 42% due to economic considerations; 15 mg/L of sodium carbonate was selected to continue the processof desorption. Increasing the desorption temperature can improve the dye desorption efficiency.According to the column test results, dye desorption concentration decreased gradually with the passing of time. The column test results showed that desorption efficiency and the percentage of dye adsorbed decreased; however, it seemed to stabilize after three repeated adsorption/desorption cycles. The repeated adsorption–desorption column tests (3 cycles) showed that the activated carbon which was prepared from walnut shell was a suitable and economical adsorbent for dye removal.
{"title":"Desorption of Reactive Red 198 from activated carbon prepared from walnut shells: effects of temperature, sodium carbonate concentration and organic solvent dose","authors":"Zohreh Alimohamadi, Habibollah Younesi, N. Bahramifar","doi":"10.22104/AET.2017.432","DOIUrl":"https://doi.org/10.22104/AET.2017.432","url":null,"abstract":"This study investigated the effect of temperature, different concentrations of sodium carbonate,and the dose of organic solvent on the desorption of Reactive Red 198 dye from dye-saturated activated carbon using batch and continuous systems. The results of the batch desorption test showed 60% acetone in water as the optimum amount. However, when the concentration of sodium carbonate was raised, the dye desorption percentage increased from 26% to 42% due to economic considerations; 15 mg/L of sodium carbonate was selected to continue the processof desorption. Increasing the desorption temperature can improve the dye desorption efficiency.According to the column test results, dye desorption concentration decreased gradually with the passing of time. The column test results showed that desorption efficiency and the percentage of dye adsorbed decreased; however, it seemed to stabilize after three repeated adsorption/desorption cycles. The repeated adsorption–desorption column tests (3 cycles) showed that the activated carbon which was prepared from walnut shell was a suitable and economical adsorbent for dye removal.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"70 1","pages":"137-141"},"PeriodicalIF":0.0,"publicationDate":"2017-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88309139","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}
In this study, the photocatalytic method was used for treating the spent caustic in the wastewater of Olefin units used in petrochemical industries which contain large amounts of total dissolved solids (TDS). By using the synthetic photocatalyst of suspended titanium dioxide and measuring the chemical oxygen demand (COD) which was reduced in the photocatalyst (lbc) process, the values of COD were modeled and evaluated by means of the Box-Behnken (BBD) and the artificial neural network (ANN) using experimental tests in a double-cylindrical-shell photo reactor. According to the applied calculations, it was found that the artificial neural network was a more suitable method than the experimental design in modeling and forecasting the amount of COD removal. The modeling employed in this research showed that increasing the concentration of the photocatalyst in a state of neutral pH enhanced the COD removal up to the optimal amount of 1.31 g/L without restrictions and 2 g/L with restrictions at the rate of 81% and 79%, respectively. In addition, the study of the parameter effects including oxidizer amount, aeration rate, pH, and the amount of loaded catalyst indicated that all factors except pH had a positive effect on the model; furthermore, if the interactions were neglected, the COD removal efficiency would increase by increasing each of these factors (except pH). In addition, there was no interaction between the aeration and the concentration of the photocatalyst, and the acidic pH was more suitable at low concentrations of the photocatalyst. Besides that, by increasing the pH, the efficiency of removal was reduced when the oxidant was at its low level. The results showed that photolysis and adsorption adoptions had a very small effect on the efficiency of the removal of COD compared to the photocatalyst adoptions, and it was insignificant. In addition, the photocatalytic method had an acceptable capacity for removing the phenol in the wastewater sample, whereas it was inefficient in reducing the sulfide solution in the wastewater.
{"title":"Photocatalytic treatment of spent caustic wastewater in petrochemical industries","authors":"A. H. Asl, A. Ahmadpour, N. Fallah","doi":"10.22104/AET.2017.443","DOIUrl":"https://doi.org/10.22104/AET.2017.443","url":null,"abstract":"In this study, the photocatalytic method was used for treating the spent caustic in the wastewater of Olefin units used in petrochemical industries which contain large amounts of total dissolved solids (TDS). By using the synthetic photocatalyst of suspended titanium dioxide and measuring the chemical oxygen demand (COD) which was reduced in the photocatalyst (lbc) process, the values of COD were modeled and evaluated by means of the Box-Behnken (BBD) and the artificial neural network (ANN) using experimental tests in a double-cylindrical-shell photo reactor. According to the applied calculations, it was found that the artificial neural network was a more suitable method than the experimental design in modeling and forecasting the amount of COD removal. The modeling employed in this research showed that increasing the concentration of the photocatalyst in a state of neutral pH enhanced the COD removal up to the optimal amount of 1.31 g/L without restrictions and 2 g/L with restrictions at the rate of 81% and 79%, respectively. In addition, the study of the parameter effects including oxidizer amount, aeration rate, pH, and the amount of loaded catalyst indicated that all factors except pH had a positive effect on the model; furthermore, if the interactions were neglected, the COD removal efficiency would increase by increasing each of these factors (except pH). In addition, there was no interaction between the aeration and the concentration of the photocatalyst, and the acidic pH was more suitable at low concentrations of the photocatalyst. Besides that, by increasing the pH, the efficiency of removal was reduced when the oxidant was at its low level. The results showed that photolysis and adsorption adoptions had a very small effect on the efficiency of the removal of COD compared to the photocatalyst adoptions, and it was insignificant. In addition, the photocatalytic method had an acceptable capacity for removing the phenol in the wastewater sample, whereas it was inefficient in reducing the sulfide solution in the wastewater.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"87 1","pages":"153-168"},"PeriodicalIF":0.0,"publicationDate":"2017-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86604954","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}
Since groundwaters are a major source of drinking water, their pollution with organic contaminants such as methyl tertiary-butyl ether (MTBE) is a very significant issue. Hence, this research investigated the photocatalytic degradation of MTBE in an aqueous solution of TiO2-ZnO-CoO nanoparticle under UV irradiation. In order to optimize photocatalytic degradation, response surface methodology was applied to assess the effects of experimental variables such as catalyst loading, initial concentration of MTBE and pH on the dye removal efficiency. The optimal condition to achieve the best degradation for the initial concentration of 30.58 mg/L of MTBE was found at a pH of 7.68 and a catalyst concentration of 1.68 g/L after 60 min.
{"title":"Employing response surface analysis using for photocatalytic degradation of MTBE by nanoparticles","authors":"Hossein Lotfi, M. Nademi, M. Mansouri, M. Olya","doi":"10.22104/AET.2017.434","DOIUrl":"https://doi.org/10.22104/AET.2017.434","url":null,"abstract":"Since groundwaters are a major source of drinking water, their pollution with organic contaminants such as methyl tertiary-butyl ether (MTBE) is a very significant issue. Hence, this research investigated the photocatalytic degradation of MTBE in an aqueous solution of TiO2-ZnO-CoO nanoparticle under UV irradiation. In order to optimize photocatalytic degradation, response surface methodology was applied to assess the effects of experimental variables such as catalyst loading, initial concentration of MTBE and pH on the dye removal efficiency. The optimal condition to achieve the best degradation for the initial concentration of 30.58 mg/L of MTBE was found at a pH of 7.68 and a catalyst concentration of 1.68 g/L after 60 min.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"2016 1","pages":"127-135"},"PeriodicalIF":0.0,"publicationDate":"2017-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86310655","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}
Titanium dioxide (TiO2) and Fe3O4 magnetite particles were coated on spherical Kissirises; glucose oxidase (GOx) enzyme was immobilized on Kissiris/Fe3O4/TiO2 by physical adsorption. This catalyst was analyzed by a scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray (EDX) measurements. The performance of the prepared biocatalyst in the decolorization of Malachite Green dye was investigated. The optimal operation parameters were 20 mg/L, 20 mM, 5.5 and 40 C for initial dye concentration, initial glucose concentration, pH and temperature, respectively. Under these conditions, a 95% Malachite Green decolorization efficiency was obtained after 150 min of reaction by using 1 g of prepared heterogeneous bio-Fenton catalyst. In this process, in contrast to a conventional Fenton’s reaction, external hydrogen peroxide and ferrous ion sources were not used. The effect of various reaction parameters such as initial concentration of dye, amount of catalyst, concentration of glucose, pH value and temperature on MG decolorization efficiency was studied.
将二氧化钛(TiO2)和Fe3O4磁铁矿颗粒包覆在球形kissiris上;采用物理吸附法将葡萄糖氧化酶(GOx)固定在Kissiris/Fe3O4/TiO2上。通过扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)和能量色散x射线(EDX)测量对该催化剂进行了分析。研究了所制备的生物催化剂对孔雀石绿染料的脱色性能。染料初始浓度为20 mg/L，葡萄糖初始浓度为20 mM, pH为5.5℃，温度为40℃。在此条件下，用1 g制备的多相生物fenton催化剂，反应150 min，孔雀石绿脱色率可达95%。在这个过程中，与传统的芬顿反应不同，没有使用外部过氧化氢和亚铁离子源。考察了染料初始浓度、催化剂用量、葡萄糖浓度、pH值、温度等反应参数对MG脱色效果的影响。
{"title":"Preparation of Kissiris/TiO2/Fe3O4/GOx Biocatalyst: Feasibility study of MG decolorization","authors":"Vahide Elhami, A. Karimi","doi":"10.22104/AET.2017.440","DOIUrl":"https://doi.org/10.22104/AET.2017.440","url":null,"abstract":"Titanium dioxide (TiO2) and Fe3O4 magnetite particles were coated on spherical Kissirises; glucose oxidase (GOx) enzyme was immobilized on Kissiris/Fe3O4/TiO2 by physical adsorption. This catalyst was analyzed by a scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray (EDX) measurements. The performance of the prepared biocatalyst in the decolorization of Malachite Green dye was investigated. The optimal operation parameters were 20 mg/L, 20 mM, 5.5 and 40 C for initial dye concentration, initial glucose concentration, pH and temperature, respectively. Under these conditions, a 95% Malachite Green decolorization efficiency was obtained after 150 min of reaction by using 1 g of prepared heterogeneous bio-Fenton catalyst. In this process, in contrast to a conventional Fenton’s reaction, external hydrogen peroxide and ferrous ion sources were not used. The effect of various reaction parameters such as initial concentration of dye, amount of catalyst, concentration of glucose, pH value and temperature on MG decolorization efficiency was studied.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"54 1","pages":"111-117"},"PeriodicalIF":0.0,"publicationDate":"2017-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89929013","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}
Pub Date : 2017-04-01DOI: 10.22104/AET.2017.1928.1092
J. Mahmoudi, M. Rahimi
In this research, the removal of lead from the aqueous solution was investigated using natural nontoxic zeolite (clinoptilolite) as a low-cost adsorbent in order to reduce human exposure to it. The clinoptilolite zeolite obtained from the Semnan area was characterized by X-ray diffraction pattern, FTIR spectroscopy and scanning electron microscopy (SEM). The central composite design (CCD) defined under the response surface methodology (RSM) was used for designing the experiments and analyzing the sorption of lead. Three parameters of contact time (43.07-101.93 min), initial concentration (508-3006 mg/L) and temperature (20-51˚C) were applied to optimize the removal percentage of lead by zeolite. It was found that the initial concentration is the most important parameter affecting the removal percentage of lead, followed by the temperature of process. The optimum values of initial concentration, contact time and temperature were found to be 2750 ppm, 82.87 min and 65°C for 99.81% removal of lead, respectively, with a high desirability of 0.990. The adsorption data fitted the Freundlich adsorption model better than the Langmuir model, with the maximum sorption capacity of the clinoptilolite zeolite for Pb(II) equaling 136.99 (mg/g).
{"title":"Studies on optimization of efficient parameters for removal of lead from aqueous solutions by natural zeolite as a low-cost adsorbent using response surface methodology","authors":"J. Mahmoudi, M. Rahimi","doi":"10.22104/AET.2017.1928.1092","DOIUrl":"https://doi.org/10.22104/AET.2017.1928.1092","url":null,"abstract":"In this research, the removal of lead from the aqueous solution was investigated using natural nontoxic zeolite (clinoptilolite) as a low-cost adsorbent in order to reduce human exposure to it. The clinoptilolite zeolite obtained from the Semnan area was characterized by X-ray diffraction pattern, FTIR spectroscopy and scanning electron microscopy (SEM). The central composite design (CCD) defined under the response surface methodology (RSM) was used for designing the experiments and analyzing the sorption of lead. Three parameters of contact time (43.07-101.93 min), initial concentration (508-3006 mg/L) and temperature (20-51˚C) were applied to optimize the removal percentage of lead by zeolite. It was found that the initial concentration is the most important parameter affecting the removal percentage of lead, followed by the temperature of process. The optimum values of initial concentration, contact time and temperature were found to be 2750 ppm, 82.87 min and 65°C for 99.81% removal of lead, respectively, with a high desirability of 0.990. The adsorption data fitted the Freundlich adsorption model better than the Langmuir model, with the maximum sorption capacity of the clinoptilolite zeolite for Pb(II) equaling 136.99 (mg/g).","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"4 1","pages":"99-108"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91179965","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}
Pub Date : 2017-04-01DOI: 10.22104/AET.2017.1740.1100
F. Sadegh‐Zadeh, S. Wahid, B. Jalili
The use of pesticides in modern agriculture is unavoidable because they are required to control weeds. Pesticides are poisonous; hence, they are dangerous if misused. Understanding the fate of pesticides will be useful to use them safely. Therefore, contaminations of water and soil resources could be avoided. The fates of pesticides in soils are influenced by their sorption, decomposition and movement. Degradation and leaching of pesticides are control by sorption. Soil organic matter and clay content are main soil constituents that have a high capacity for sorption of pesticides. Addition of organic maters to amend the soils is a usual practice that every year has been done in a huge area of worldwide. The added organic amendments to the soils affect the fate of pesticides in soils as well. Pesticides fates in different soils are different. The addition of organic matter to soils causes different fates for pesticides as well. It is known from the studies that sorption of non-ionic pesticides by soil in aqueous system is controlled mainly by the organic matter content of the soils. Sorption of pesticides has been reported to increase by amending soils with organic matter. In general, conditions that promote microbial activity enhance the rate of pesticides degradation, and those that inhibit the growth of microorganisms reduce the rate of degradation. Amendment of soils with organic matter may modify leaching of pesticides in soil. Some studies showed that organic matter added to soils reduced pesticides in ground water. Generally, organic amendments induces the restriction of pesticides leaching in soils.
{"title":"Sorption, degradation and leaching of pesticides in soils amended with organic matter: A review","authors":"F. Sadegh‐Zadeh, S. Wahid, B. Jalili","doi":"10.22104/AET.2017.1740.1100","DOIUrl":"https://doi.org/10.22104/AET.2017.1740.1100","url":null,"abstract":"The use of pesticides in modern agriculture is unavoidable because they are required to control weeds. Pesticides are poisonous; hence, they are dangerous if misused. Understanding the fate of pesticides will be useful to use them safely. Therefore, contaminations of water and soil resources could be avoided. The fates of pesticides in soils are influenced by their sorption, decomposition and movement. Degradation and leaching of pesticides are control by sorption. Soil organic matter and clay content are main soil constituents that have a high capacity for sorption of pesticides. Addition of organic maters to amend the soils is a usual practice that every year has been done in a huge area of worldwide. The added organic amendments to the soils affect the fate of pesticides in soils as well. Pesticides fates in different soils are different. The addition of organic matter to soils causes different fates for pesticides as well. It is known from the studies that sorption of non-ionic pesticides by soil in aqueous system is controlled mainly by the organic matter content of the soils. Sorption of pesticides has been reported to increase by amending soils with organic matter. In general, conditions that promote microbial activity enhance the rate of pesticides degradation, and those that inhibit the growth of microorganisms reduce the rate of degradation. Amendment of soils with organic matter may modify leaching of pesticides in soil. Some studies showed that organic matter added to soils reduced pesticides in ground water. Generally, organic amendments induces the restriction of pesticides leaching in soils.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"31 1","pages":"119-132"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74830703","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}
In this research modified Kaolin by Cetyltrimethylammonium bromide is used as an adsorbent for the removal of Reactive Blue 21 from aqueous solutions. Response Surface Methodology was used to study the effect of independent variables, such as Reactive Blue 21 dye concentration (20, 40, 60, 80 and 100 mg/L), time (10, 20, 30, 40 and 50), initial pH (2, 4, 6, 8 and 10) and modified Kaolin dosage (0.05, 0.1, 0.15, 0.2 and 0.25 g/50 mL) on dye removal efficiency from aqueous solutions. At the optimum conditions, predicted removal of Reactive Blue 21 by modified Kaolin was 98.26%. The confirmatory experiment was conducted, which confirmed the results by 94.42 % dye removal. Thus, the experimental investigation and statistical approach enabled us to predict Reactive Blue 21 removal by modified Kaolin. Also, the kinetics and isotherm adsorption of Reactive Blue 21 onto modified Kaolin was obeyed pseudo-second order kinetics and Langmuir isotherm.
{"title":"Response Surface Methodology for Optimizing Adsorption Process Parameters of Reactive Blue 21 onto Modified Kaolin","authors":"P. Gharbani, A. nojavan","doi":"10.22104/AET.2017.505","DOIUrl":"https://doi.org/10.22104/AET.2017.505","url":null,"abstract":"In this research modified Kaolin by Cetyltrimethylammonium bromide is used as an adsorbent for the removal of Reactive Blue 21 from aqueous solutions. Response Surface Methodology was used to study the effect of independent variables, such as Reactive Blue 21 dye concentration (20, 40, 60, 80 and 100 mg/L), time (10, 20, 30, 40 and 50), initial pH (2, 4, 6, 8 and 10) and modified Kaolin dosage (0.05, 0.1, 0.15, 0.2 and 0.25 g/50 mL) on dye removal efficiency from aqueous solutions. At the optimum conditions, predicted removal of Reactive Blue 21 by modified Kaolin was 98.26%. The confirmatory experiment was conducted, which confirmed the results by 94.42 % dye removal. Thus, the experimental investigation and statistical approach enabled us to predict Reactive Blue 21 removal by modified Kaolin. Also, the kinetics and isotherm adsorption of Reactive Blue 21 onto modified Kaolin was obeyed pseudo-second order kinetics and Langmuir isotherm.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"95 1","pages":"89-98"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83929354","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}
Pub Date : 2017-04-01DOI: 10.22104/AET.2017.1802.1084
K. Movagharnejad, Alireza Tahavvori, F. M. Ali
The water quality of the Karaj River was studied through collecting 2137 experimental data set gained by 20 sampling stations. The data included different parameters such as T (temperature), pH, NTU (turbidity), hardness, TDS (total dissolved solids), EC (electrical conductivity) and basic anion, cation concentrations. In this study a multi-layer perceptron artificial neural network model was designed to predict the calcium, sodium, chloride and sulfate ion concentrations of the Karaj River. 1495 data set were used for training, 321 data set were used for test and 321 data set were used for validation. The optimum model holds sigmoid tangent transfer function in the middle layer and three different forms of the training function. The root mean square error (RMSE), mean relative error (MRE) and regression coefficient (R) between experimental data and model’s outputs were measured for training, validation and testing data sets. The results indicate that the ANN model was successfully applied for prediction of calcium ion concentration.
{"title":"Artificial Neural Network Modeling for Predicting of some Ion Concentrations in the Karaj River","authors":"K. Movagharnejad, Alireza Tahavvori, F. M. Ali","doi":"10.22104/AET.2017.1802.1084","DOIUrl":"https://doi.org/10.22104/AET.2017.1802.1084","url":null,"abstract":"The water quality of the Karaj River was studied through collecting 2137 experimental data set gained by 20 sampling stations. The data included different parameters such as T (temperature), pH, NTU (turbidity), hardness, TDS (total dissolved solids), EC (electrical conductivity) and basic anion, cation concentrations. In this study a multi-layer perceptron artificial neural network model was designed to predict the calcium, sodium, chloride and sulfate ion concentrations of the Karaj River. 1495 data set were used for training, 321 data set were used for test and 321 data set were used for validation. The optimum model holds sigmoid tangent transfer function in the middle layer and three different forms of the training function. The root mean square error (RMSE), mean relative error (MRE) and regression coefficient (R) between experimental data and model’s outputs were measured for training, validation and testing data sets. The results indicate that the ANN model was successfully applied for prediction of calcium ion concentration.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"5 1","pages":"109-117"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90928945","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}
Pub Date : 2017-04-01DOI: 10.22104/AET.2017.2003.1099
F. Akhlaghian, B. Souri, Z. Mohamadi
The presence of arsenate in drinking water causes adverse health effects including skin lesions, diabetes, cancer, damage to the nervous system, and cardiovascular diseases. Therefore, the removal of As (V) from water is necessary. In this work, nanostructured adsorbent Fe2O3/Al2O3 was synthesized via the sol-gel method and applied to remove arsenate from polluted waters. First, the Fe2O3 load of the adsorbent was optimized. The Fe2O3/Al2O3 adsorbent was characterized by means of XRF, XRD, ASAP, and SEM techniques. The effects of the operating conditions of the batch process of As (V) adsorption such as pH, adsorbent dose, contact time, and initial concentration of As (V) solution were studied, and optimized. The thermodynamic study of the process showed that arsenate adsorption was endothermic. The kinetic model corresponded to the pseudo-second-order model. The Langmuir adsorption isotherm was better fitted to the experimental data. The Fe2O3/Al2O3 adsorbent was immobilized on leca granules and applied for As (V) adsorption. The results showed that the immobilization of Fe2O3/Al2O3 on leca particles improved the As (V) removal efficiency.
{"title":"Nanostructured Fe2O3/Al2O3 Adsorbent for removal of As (V) from water","authors":"F. Akhlaghian, B. Souri, Z. Mohamadi","doi":"10.22104/AET.2017.2003.1099","DOIUrl":"https://doi.org/10.22104/AET.2017.2003.1099","url":null,"abstract":"The presence of arsenate in drinking water causes adverse health effects including skin lesions, diabetes, cancer, damage to the nervous system, and cardiovascular diseases. Therefore, the removal of As (V) from water is necessary. In this work, nanostructured adsorbent Fe2O3/Al2O3 was synthesized via the sol-gel method and applied to remove arsenate from polluted waters. First, the Fe2O3 load of the adsorbent was optimized. The Fe2O3/Al2O3 adsorbent was characterized by means of XRF, XRD, ASAP, and SEM techniques. The effects of the operating conditions of the batch process of As (V) adsorption such as pH, adsorbent dose, contact time, and initial concentration of As (V) solution were studied, and optimized. The thermodynamic study of the process showed that arsenate adsorption was endothermic. The kinetic model corresponded to the pseudo-second-order model. The Langmuir adsorption isotherm was better fitted to the experimental data. The Fe2O3/Al2O3 adsorbent was immobilized on leca granules and applied for As (V) adsorption. The results showed that the immobilization of Fe2O3/Al2O3 on leca particles improved the As (V) removal efficiency.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"82 1","pages":"67-75"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84420441","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 sorption efficiencies of graphene oxide (GO) and functionalized multi-walled carbon nanotubes (f-MWCNTs) were investigated and elucidated to study their potential in treating acid mine drainage (AMD) containing Cu2+, Mn2+, Zn2+, Pb2+, Fe3+ and Cd2+ metal ions. Several layered GO nanosheets and f-MWCNTs were formed via the modified Hummers’ method and the acid treatment of the MWCNTs, respectively. The prepared nanoadsorbents were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transformed infrared (FTIR) spectroscopy, and BET surface area analysis. The batch method was utilized to evaluate the pH effect, sorption kinetics and isotherms. The results demonstrated that the sorption capacities of the MWCNTs increased greatly after oxidation and those of the GO decreased after reduction. Hence, the sorption mechanisms seemed principally assignable to the chemical interactions between the metal ions and the surface functional groups of the adsorbents. Additionally, the adsorption isotherm results clearly depicted that the adsorption of the Cu2+ ion onto the GO adsorbent surface was well fitted and found to be in good agreement with the Langmuir isotherm model as the obtained regression constant value (R2) was found to be 0.9981. All results indicated that GO was a promising material for the removal of toxic metal ions from aqueous solutions in actual pollution management.
{"title":"Toxic metal removal from aqueous solution by advanced Carbon allotropes: a case study from the Sungun Copper Mine","authors":"E. Rahimi","doi":"10.22104/AET.2017.507","DOIUrl":"https://doi.org/10.22104/AET.2017.507","url":null,"abstract":"The sorption efficiencies of graphene oxide (GO) and functionalized multi-walled carbon nanotubes (f-MWCNTs) were investigated and elucidated to study their potential in treating acid mine drainage (AMD) containing Cu2+, Mn2+, Zn2+, Pb2+, Fe3+ and Cd2+ metal ions. Several layered GO nanosheets and f-MWCNTs were formed via the modified Hummers’ method and the acid treatment of the MWCNTs, respectively. The prepared nanoadsorbents were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transformed infrared (FTIR) spectroscopy, and BET surface area analysis. The batch method was utilized to evaluate the pH effect, sorption kinetics and isotherms. The results demonstrated that the sorption capacities of the MWCNTs increased greatly after oxidation and those of the GO decreased after reduction. Hence, the sorption mechanisms seemed principally assignable to the chemical interactions between the metal ions and the surface functional groups of the adsorbents. Additionally, the adsorption isotherm results clearly depicted that the adsorption of the Cu2+ ion onto the GO adsorbent surface was well fitted and found to be in good agreement with the Langmuir isotherm model as the obtained regression constant value (R2) was found to be 0.9981. All results indicated that GO was a promising material for the removal of toxic metal ions from aqueous solutions in actual pollution management.","PeriodicalId":7295,"journal":{"name":"Advances in environmental science and technology","volume":"88 1","pages":"77-87"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91111309","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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