University of Isfahan Iranian Journal of Environmental Technology 2423-5776 2 1 2016 04 01 The conversion of nitrate in water to diatomic nitrogen gas by immobilized Pseudomonas stutzeri on vermiculite The conversion of nitrate in water to diatomic nitrogen gas by immobilized Pseudomonas stutzeri on vermiculite 1 9 21065 10.22108/ijet.2016.21065 EN Badri Fazeli M.Sc. of Microbiology, University of Isfahan, Iran Giti Emtiazi Professor of Microbiology, University of Isfahan, Iran Journal Article 2016 02 14 Denitrification is a reduction of nitrate by heterotrophic and autotrophic bacteria that may ultimately produce molecular nitrogen (N2) through a series of intermediate nitrogen compounds.Vermiculite is a hydrous phyllosilicate mineral (Mg, Fe+2,Fe+3)3[(Al,Si)4O10](OH)2·4H2O with several layers for bacterial immobilization. The goal of this study was removal of nitrate from water with vermiculite and bacterial bio-film. In this process, 2×107 of bacteria were trapped in one gram vermiculite with resting cells and growing cells and nitrate removal were compared by free cells. The data showed that the un-immobilized cell in resting state could only remove 45 mg nitrate in 5 days, however nitrate removal by resting cell on vermiculite was 180 mg in 10 days, while in free resting cells this removal was poor. The maximum removal of 450 mg nitrate occurred after 25 days with feeding of biofilm. The intermediate product of nitrate removal was nitrite and in all data, the end product was nitrogen. Highlights Immobilization of P. stutzeri in resting cell status,improved nitrate removal efficiency versus un-immobilized bacteria. Feeding the immobilized bacteria, improved nitrate removal efficiency. Vermiculite introduced as a beneficial support media for immobilization of bacteria. Denitrification is a reduction of nitrate by heterotrophic and autotrophic bacteria that may ultimately produce molecular nitrogen (N2) through a series of intermediate nitrogen compounds.Vermiculite is a hydrous phyllosilicate mineral (Mg, Fe+2,Fe+3)3[(Al,Si)4O10](OH)2·4H2O with several layers for bacterial immobilization. The goal of this study was removal of nitrate from water with vermiculite and bacterial bio-film. In this process, 2×107 of bacteria were trapped in one gram vermiculite with resting cells and growing cells and nitrate removal were compared by free cells. The data showed that the un-immobilized cell in resting state could only remove 45 mg nitrate in 5 days, however nitrate removal by resting cell on vermiculite was 180 mg in 10 days, while in free resting cells this removal was poor. The maximum removal of 450 mg nitrate occurred after 25 days with feeding of biofilm. The intermediate product of nitrate removal was nitrite and in all data, the end product was nitrogen. Highlights Immobilization of P. stutzeri in resting cell status,improved nitrate removal efficiency versus un-immobilized bacteria. Feeding the immobilized bacteria, improved nitrate removal efficiency. Vermiculite introduced as a beneficial support media for immobilization of bacteria.

https://ijet.ui.ac.ir/article_21065_fd3c8cdc364d978d10330cb6fbf7a550.pdf

University of Isfahan Iranian Journal of Environmental Technology 2423-5776 2 1 2016 04 01 Comparison of central composite design and artificial neural network approaches for modeling and optimization of 2-methylpropane-2-thiol removal from contaminated soil by ultrasound Comparison of central composite design and artificial neural network approaches for modeling and optimization of 2-methylpropane-2-thiol removal from contaminated soil by ultrasound 11 26 21064 10.22108/ijet.2016.21064 EN Pejman Roohi Ph.D. Student of Chemical engineering, Environmental Engineering Research Center (EERC), Sahand University of Technology, Sahand New Town, Tabriz, Iran Esmaeil Fatehifar Professor of Chemical engineering, Environmental Engineering Research Center (EERC), Sahand University of Technology, Sahand New Town, Tabriz, Iran Reza Alizadeh Associate Professor of Chemical Engineering, Environmental Engineering Research Center (EERC), Sahand University of Technology, Sahand New Town, Tabriz, Iran Journal Article 2016 01 27 In this article a comparative study for modeling and optimization of 2-methylpropane-2-thiol removal from contaminated soil by ultrasound is investigated. Central Composite Design (CCD) and artificial neural network (ANN) were utilized and compared to each other in order to obtain appropriate predicting model with respect to sonication power (w), sonication time (min) and water/reactor volume ratio (ml/ml). CCD was used based on Response Surface Model (RSM) and the ANN model was developed by the Levenberg−Marquardt feed forward back-propagation training algorithm and topology (3:8:1). Analysis of variance and Pareto analysis resulted from CCD demonstrate that sonication power is the most influential parameter on 2-methylpropane-2-thiol removal efficiency (sonication time and amount of added water in the next order respectively). This is confirmed by ANN model. Also interaction between water content and power, sonication time and power are effective interaction (P-values=0.025 and 0.007 respectively). Comparison between CCD and ANN methods demonstrate that ANN model has excellent predicting power compared to CCD model and both of them show good agreement with experimental values with high correlation coefficients (R2ANN=98.39%, R2CCD=96.34%). Optimized condition suggests that for maximum removal efficiency (82.83%), power and sonication time must be in highest level and water/reactor volume ratio must be in lowest level in the studied interval. Highlights Soil polluted with 2-methylpropane-2-thiol is remediated with sonication process. The effects of the sonication power (w), sonication time (min) and water/reactor volume ratio (ml/ml) are added to the batch reactor as the main factor and interaction between them are investigated. For preparing the best experimental model CCD and ANN methods are used and compared to each other. In this article a comparative study for modeling and optimization of 2-methylpropane-2-thiol removal from contaminated soil by ultrasound is investigated. Central Composite Design (CCD) and artificial neural network (ANN) were utilized and compared to each other in order to obtain appropriate predicting model with respect to sonication power (w), sonication time (min) and water/reactor volume ratio (ml/ml). CCD was used based on Response Surface Model (RSM) and the ANN model was developed by the Levenberg−Marquardt feed forward back-propagation training algorithm and topology (3:8:1). Analysis of variance and Pareto analysis resulted from CCD demonstrate that sonication power is the most influential parameter on 2-methylpropane-2-thiol removal efficiency (sonication time and amount of added water in the next order respectively). This is confirmed by ANN model. Also interaction between water content and power, sonication time and power are effective interaction (P-values=0.025 and 0.007 respectively). Comparison between CCD and ANN methods demonstrate that ANN model has excellent predicting power compared to CCD model and both of them show good agreement with experimental values with high correlation coefficients (R2ANN=98.39%, R2CCD=96.34%). Optimized condition suggests that for maximum removal efficiency (82.83%), power and sonication time must be in highest level and water/reactor volume ratio must be in lowest level in the studied interval. Highlights Soil polluted with 2-methylpropane-2-thiol is remediated with sonication process. The effects of the sonication power (w), sonication time (min) and water/reactor volume ratio (ml/ml) are added to the batch reactor as the main factor and interaction between them are investigated. For preparing the best experimental model CCD and ANN methods are used and compared to each other.

https://ijet.ui.ac.ir/article_21064_6e90c9d89015a9f0596963788902cf9c.pdf

University of Isfahan Iranian Journal of Environmental Technology 2423-5776 2 1 2016 04 01 Evaluation of moving bed biofilm reactor (MBBR) by applying adaptive neuro-fuzzy inference systeme (ANFIS), radial basis function (RBF) and Fuzzy Regression Analysis Evaluation of moving bed biofilm reactor (MBBR) by applying adaptive neuro-fuzzy inference systeme (ANFIS), radial basis function (RBF) and Fuzzy Regression Analysis 27 40 21066 10.22108/ijet.2016.21066 EN Mohammad Delnavaz Assistant Professor of Environmental engineering, Kharazmi University, Tehran, Iran Hossein Zangooei MSc. of Environmental engineering, Kharazmi University, Tehran, Iran Journal Article 2016 03 14 The purpose of this study is to investigate the accuracy of predictions of aniline removal efficiency in a moving bed biofilm reactor (MBBR) by various methods, namely by RBF, ANFIS, and fuzzy regression analysis. The reactor was operated in an aerobic batch and was filled by light expanded clay aggregate (LECA) as a carrier for the treatment of Aniline synthetic wastewater. Exploratory data analysis was used to detect relationships between the independent and the dependent evaluated data. The models were found to be efficient and robust tools in predicting MBBR performance. Results showed that increasing the neurons in the hidden layer would improve the function of RBF network. The ANFIS model made according to the membership functions of generalized bell, triangular, and Gaussian with R2 equals to 0.99 and RMS error of 0.027 for the anticipation of the concentration of Aniline and R2 equals to 0.99 and RMS error of 0.034 for the prediction of removal COD efficiency. Highlights Application of ANN-based models (RBF network), ANFIS models and Fuzzy regression as a robust tool in predicting MBBR efficiency Determination of process efficiency in various operation conditions for the treatment of aniline synthetic wastewater ANFIS had more ability than fuzzy regression analysis in simulating and predicting removal efficiency in different experimental conditions. The purpose of this study is to investigate the accuracy of predictions of aniline removal efficiency in a moving bed biofilm reactor (MBBR) by various methods, namely by RBF, ANFIS, and fuzzy regression analysis. The reactor was operated in an aerobic batch and was filled by light expanded clay aggregate (LECA) as a carrier for the treatment of Aniline synthetic wastewater. Exploratory data analysis was used to detect relationships between the independent and the dependent evaluated data. The models were found to be efficient and robust tools in predicting MBBR performance. Results showed that increasing the neurons in the hidden layer would improve the function of RBF network. The ANFIS model made according to the membership functions of generalized bell, triangular, and Gaussian with R2 equals to 0.99 and RMS error of 0.027 for the anticipation of the concentration of Aniline and R2 equals to 0.99 and RMS error of 0.034 for the prediction of removal COD efficiency. Highlights Application of ANN-based models (RBF network), ANFIS models and Fuzzy regression as a robust tool in predicting MBBR efficiency Determination of process efficiency in various operation conditions for the treatment of aniline synthetic wastewater ANFIS had more ability than fuzzy regression analysis in simulating and predicting removal efficiency in different experimental conditions.

https://ijet.ui.ac.ir/article_21066_877e87875cc41f9b7bc8841dcfd0acca.pdf

University of Isfahan Iranian Journal of Environmental Technology 2423-5776 2 1 2016 04 01 The effect of isolated phosphorus solubilizing bacteria and molasses on Soluble and available P in wheat straw medium The effect of isolated phosphorus solubilizing bacteria and molasses on Soluble and available P in wheat straw medium 41 48 21067 10.22108/ijet.2016.21067 EN Kobra Sheikhi M.Sc of Soil science, University of Yasouj Ebrahim Adhami Associate professorof Soil science, University of Yasouj, Iran Reza Naghiha Assistant professor of Microbiology,University of Yasouj, Iran Hamidreza Owliai Associate professor of Soil science, University of Yasouj, Iran Journal Article 2016 05 01 Phosphorus solubilizing microorganisms are capable of transforming insoluble phosphorus (P) forms to soluble and bioavailable P. The aim of the present study was to isolate P solubilizing bacteria from forest soils around the rock phosphate (RP) mine of Koh-e-SepidLar in Kohgiluyeh and Boyer Ahmad province and evaluate their ability in Sperber culture medium and wheat straw medium in the presence of RP and molasses. Bacteria were isolated and conducted by serial dilution and culturedon Pikovskaya medium. Quantitative assessment of 6 isolated bacteria carried out in the Sperber medium with tricalcium phosphate with 3 replications. Soluble P was measured on 5, 10, 15 and 20 days. The ability of two most effective bacteria in the liquid culture, assessed in wheat straw medium in a completely randomized design. Treatments consisted of a factorial combination of three RP levels (zero, 1:8 and 1:4 RP: wheat straw) and molasses in three rates (zero, 0.5 and 1% w/w) and three bacteria levels (none inoculated, and inoculated with isolates 1 and 2, separately). Soluble P and available P were measured on 20 and 40 days with CaCl2 0.01 M and NaHCO3 0.5 M, respectively. Some bacteria with P solubilizing capability found in the Pikovskaya medium. Two isolates showed the highest ability in liquid culture. CaCl2-P in the presence of isolates 1 and 2 was higher than blank in wheat straw medium. Molasses caused the increase of CaCl2-P in both times. Presence of RP reduced CaCl2-P. Highlights Isolation of P solubilizing bacteria from forest soils around the rock phosphate (RP) mine in Kohgiluyeh and Boyer Ahmad Molasses caused the increase of CaCl2-P in both time. Presence of RP reduced CaCl2-P. Phosphorus solubilizing microorganisms are capable of transforming insoluble phosphorus (P) forms to soluble and bioavailable P. The aim of the present study was to isolate P solubilizing bacteria from forest soils around the rock phosphate (RP) mine of Koh-e-SepidLar in Kohgiluyeh and Boyer Ahmad province and evaluate their ability in Sperber culture medium and wheat straw medium in the presence of RP and molasses. Bacteria were isolated and conducted by serial dilution and culturedon Pikovskaya medium. Quantitative assessment of 6 isolated bacteria carried out in the Sperber medium with tricalcium phosphate with 3 replications. Soluble P was measured on 5, 10, 15 and 20 days. The ability of two most effective bacteria in the liquid culture, assessed in wheat straw medium in a completely randomized design. Treatments consisted of a factorial combination of three RP levels (zero, 1:8 and 1:4 RP: wheat straw) and molasses in three rates (zero, 0.5 and 1% w/w) and three bacteria levels (none inoculated, and inoculated with isolates 1 and 2, separately). Soluble P and available P were measured on 20 and 40 days with CaCl2 0.01 M and NaHCO3 0.5 M, respectively. Some bacteria with P solubilizing capability found in the Pikovskaya medium. Two isolates showed the highest ability in liquid culture. CaCl2-P in the presence of isolates 1 and 2 was higher than blank in wheat straw medium. Molasses caused the increase of CaCl2-P in both times. Presence of RP reduced CaCl2-P. Highlights Isolation of P solubilizing bacteria from forest soils around the rock phosphate (RP) mine in Kohgiluyeh and Boyer Ahmad Molasses caused the increase of CaCl2-P in both time. Presence of RP reduced CaCl2-P.

https://ijet.ui.ac.ir/article_21067_03b20e0d44fb2e9ed3ab52f2a2650d56.pdf

University of Isfahan Iranian Journal of Environmental Technology 2423-5776 2 1 2016 03 20 Municipal Waste Landfill Site Selection based on Environmental, Geological and Geotechnical Multi-criteria: A Case Study Municipal Waste Landfill Site Selection based on Environmental, Geological and Geotechnical Multi-criteria: A Case Study 49 67 22549 10.22108/ijet.2018.107396.1003 EN Akbar Ghazifard Associate professor of Geo-environmental Engineering, Department of Geology, University of Isfahan, Iran Shahrzad Nikoobakht M.Sc. of Geological Engineering, Department of Geology, University of Yazd, Yazd, Iran Mohammad Azarafza Ph.D. of Geological Engineering, Department of Geology, University of Isfahan, Isfahan, Iran Journal Article 2017 10 21 Waste management is a complex and detailed process that involves evaluation of certain important factors, such as a geological, geotechnical, hydrological, hydrogeological, climate, urban management, environmental, along with social, cultural, and psychological parameters. Unfortunately, in Iran, there is minimal evaluation of initial parameters and in some cases even don’t exist. The purpose of this study is to conduct a landfill site selection based on engineering geological views. For this purpose, the Analytical Hierarchy Process (AHP), Multiple Criteria Decision Making (MCDM) and Geographic Information Systems (GIS) methods were used to select a suitable site for disposal of municipal solid waste (MSW) for the city of Maragheh, Iran. In order to make decision for landfill site selection, the focus was on multivariable function of the listed criteria. Each of these criteria is classified based on international guidelines (US environmental protection agency and technical committee on geotechnical landfill engineering), field studies, and laboratory tests. Based on the results, Three sites were recommended for municipal solid waste landfill (Sites ‘A’, ‘B’ and ‘C’). From these sites, sampling and soil mechanics tests (sieve analysis and Atterberg limits) were conducted where categorised according to USCS classification system. Finally, with AHP and MCDM methods the ‘Site A’ was recommended as the best location for sanitary landfill. Waste management is a complex and detailed process that involves evaluation of certain important factors, such as a geological, geotechnical, hydrological, hydrogeological, climate, urban management, environmental, along with social, cultural, and psychological parameters. Unfortunately, in Iran, there is minimal evaluation of initial parameters and in some cases even don’t exist. The purpose of this study is to conduct a landfill site selection based on engineering geological views. For this purpose, the Analytical Hierarchy Process (AHP), Multiple Criteria Decision Making (MCDM) and Geographic Information Systems (GIS) methods were used to select a suitable site for disposal of municipal solid waste (MSW) for the city of Maragheh, Iran. In order to make decision for landfill site selection, the focus was on multivariable function of the listed criteria. Each of these criteria is classified based on international guidelines (US environmental protection agency and technical committee on geotechnical landfill engineering), field studies, and laboratory tests. Based on the results, Three sites were recommended for municipal solid waste landfill (Sites ‘A’, ‘B’ and ‘C’). From these sites, sampling and soil mechanics tests (sieve analysis and Atterberg limits) were conducted where categorised according to USCS classification system. Finally, with AHP and MCDM methods the ‘Site A’ was recommended as the best location for sanitary landfill.

https://ijet.ui.ac.ir/article_22549_687d0876411409a53f6081f2f7655966.pdf

University of Isfahan Iranian Journal of Environmental Technology 2423-5776 2 1 2018 08 21 Photoreduction of Potassium Dichromate in Aqueous Solution using Cobalt doped ZnO Nanoparticles Photoreduction of Potassium Dichromate in Aqueous Solution using Cobalt doped ZnO Nanoparticles 69 80 22847 10.22108/ijet.2018.111579.1005 EN Abdollah Fallah Shojaei Department of Chemistry, Faculty of Science, University of Guilan, Rasht, Iran Shiva Fathi Department of Chemistry, Faculty of Science, University of Guilan, Rasht, Iran Journal Article 2018 06 21 Co-doped ZnO nanoparticles with different Cobalt contents were prepared by direct precipitation method. The materials were characterized by XRD, SEM and TEM techniques. The XRD results indicated that the particle size of pure ZnO and Co-doped ZnO is about 30-45nm. The toxic Cr(VI) in industrial wastewaters can be removed by a reduction from Cr(VI) to Cr(III). The reduction of Cr(VI) to Cr(III) can be achieved by a photocatalytic process. The effect of Co loading on the photocatalytic activity of Co-doped ZnO in the reduction of Cr(VΙ) was studied and the results are compared with the pure ZnO. The results showed that the rate of photoreduction of Cr(VΙ) over Co-doped ZnO is much higher as compared to that of pure ZnO. The photocatalytic reaction were carried out under UV radiation towards the reduction of Cr(VI) by varying different parameters such as irradiation time, pH of the solution, catalyst amount and substrate concentration.

https://ijet.ui.ac.ir/article_22847_66cc7a11e4f0ca7b4200c84bc073580f.pdf