Iranian Research Organization for Science and TechnologyAdvances in Environmental Technology2476-66745420191001Bentazon removal from aqueous solution by reverse osmosis; optimization of effective parameters using response surface methodology19320194110.22104/aet.2020.4228.1209ENMohammadNematzadehDepartment of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, IranAbdolrezaSamimiDepartment of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, IranSoheilaShokrollahzadehDepartment of Chemical Technologies, Iranian Research Organization for Science and TechnologyDavodMohebbi-KalhoriDepartment of Chemical Engineering, University of Sistan and Baluchestan, Zahedan, IranJournal Article20200521Although bentazon is widely used as an agricultural herbicide, it is harmful to humans and poses many environmental threats. This study focused on the treatment of wastewater contaminated with bentazon pesticides using membrane technology. In this regard, low-pressure reverse osmosis (RO) was employed as it has already been used in the removal of other micro-pollutants. The effects of process variables on water flux and bentazon rejection were studied: temperature, pressure, and bentazon feed concentration. Based on central composite design (CCD), the quadratic model was engaged to correlate the process variables with the water flux and the bentazon removal responses. The obtained results showed that the bentazon rejection increased by enhancing the pressure while it decreased at higher feed solution concentration. However, with increasing temperature, the amount of bentazon removal was reduced. A bentazon rejection efficiency of 100 % could be achieved under optimum conditions (i.e., the temperature of 29.8 ℃ and hydrostatic pressure of 12.6 bar for a feed solution concentration of 66.9 mg/L). Therefore, reverse osmosis can effectively remove bentazon.https://aet.irost.ir/article_941_9355d6b1b9ecee85d1796d1e087b8ce1.pdfIranian Research Organization for Science and TechnologyAdvances in Environmental Technology2476-66745420191001Sorption of cd (II) ions by chitosan modified peanut shell biochar from aqueous solution20321197110.22104/aet.2020.4332.1220ENHadisehShabaniDepartment of Soil Science, College of Agriculture, University of Zanjan, Zanjan, IranMohammad AmirDelavarDepartment of Soil Science, College of Agriculture, University of Zanjan, Zanjan, IranSaeidTaghavi FardoodDepartment of Chemistry, University of Zanjan, Zanjan, IranJournal Article20200801In this paper, biochar was prepared from peanut shells, and then the pristine biochar (PBc) was modified by chitosan (CBc). The characteristics of the absorbents were investigated using infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Brunauer, Emmett and Teller analysis (BET). The effects of the biochars dosage, pH, initial cadmium concentration, and contact time on cadmium removal were evaluated. Adsorption isotherms and kinetic models were used to explain the adsorption process. The results indicated that CBc could be used as a biosorbent for the removal of heavy metals from the aqueous solution. The adsorption data conformed best to the Langmuir isotherm. Optimum conditions for the highest removal of Cd (II) were obtained at the biochar dosage of 0.6 g/L, 30 mg/L initial concentration of Cd (II) solution, pH value of 6, and within 30 minutes. The maximum adsorption capacities of pristine and modified biochar were found to be 40 mg/g and 58.823 mg/g, respectively. The kinetic data displayed that pseudo-second-order kinetic model can well fit the process of cadmium biosorption. The coatings of biochar with chitosan can greatly improve the absorbent efficiency in the removal of heavy metals and the chitosan-modified biochar can be used as a, low-cost, effective and environmental-friendly adsorbent.https://aet.irost.ir/article_971_5791ff4ed81ab7c94699cfef40301788.pdfIranian Research Organization for Science and TechnologyAdvances in Environmental Technology2476-66745420191001A Green Route for Wasted Sulfur Consumption: Kinetic Modelling of Methyl Mercaptan Synthesis from Refinery H2S Streams over the K2Wo4/Al2O3 Catalyst21321997610.22104/aet.2020.4414.1236ENSeyed AbdolmajidKhaksarDepartment of Chemical Engineering, University of Sistan and Balouchestan, Zahedan, IranMortazaZivdarDepartment of Chemical Engineering, University of Sistan and Balouchestan, Zahedan, IranRahbarRahimiDepartment of Chemical Engineering, University of Sistan and Balouchestan, Zahedan, IranJournal Article20200915The kinetics of methyl mercaptan production from a reaction between methanol and hydrogen sulfide in the presence of a K<sub>2</sub>Wo<sub>4</sub>/Al<sub>2</sub>O<sub>3</sub> catalyst was experimentally studied. Waste streams containing sulfur due to sour gas sweetening in the Nori refinery complex were used instead of pure H<sub>2</sub>S. This reaction can eliminate the emission of sulfur-containing compounds into the environment and convert them into useful products. The experiments were performed over a fixed-bed reactor at various temperatures and a pressure of 8-10 bars. The values of kinetic parameters estimated by the regression between the kinetic models and the experiments within the ranges have been reported in the literature. The activation energies for methyl mercaptan and dimethyl sulfide were 53.11 and 129.55 (kJ/mol), respectively. ASPEN simulation showed that the molar flow rates of H<sub>2</sub>S and methanol (reactants) decreased at the length of the reactor, while this trend for the products (methyl mercaptan, DMS, and H<sub>2</sub>O) was reversed. The correlation coefficients indicated that the parameters and the model were significant and reasonable for reactor design. The results showed that sulfur-containing waste streams could be used instead of pure H<sub>2</sub>S streams. This substitution not only provides a supply for replacing pure H<sub>2</sub>S streams but also contains the emission of poisonous sulfur compounds into the environment.https://aet.irost.ir/article_976_a38a804c3227c93e000914ecfc71e847.pdfIranian Research Organization for Science and TechnologyAdvances in Environmental Technology2476-66745420191001Environmental risk assessment and source apportionment of heavy metals in soils and natural plants surrounding a cement factory in NE Iran22122797810.22104/aet.2020.4465.1244ENYaserSafariShahrood University of TechnologyMahboobehKarimiMSc in Soil Science, Central Laboratory, Faculty of Agriculture and Animal Science, University of Torbat-e-Jam, IranJournal Article20201017Introducing different heavy metals (HMs) into the environment through cement production has been recognized as a serious concern globally. The present study was carried out to assess the environmental risk of chromium (Cr), nickel (Ni), lead (Pb), and cadmium (Cd) pollution in the soil and plants surrounding the Shahrood Cement Factory, Northeast Iran. A total of 35 surface soil samples (0–10 cm) and 23 natural plant samples were collected. After preparation, the soil samples and plant tissues were analyzed for their total concentration of Cr, Ni, Pb, and Cd. In addition to normal statistical analyses, the inverse distance weighting (IDW) method was applied to prepare the thematic distribution maps. The results showed that the total Cr, Ni, Cd, and Pb soil concentrations ranged from 4.19 to 21.74, 2.11 to 41.20, 0.77 to 4.23, and 2.72 to 54.50, respectively. Comparing the soil content of the studied HMs with their national threshold values revealed that except for Cd in limited locations, other HMs were substantially lower than their permissible limits, indicating that the area was not polluted. The spatial distribution maps of selected HMs suggested an anthropogenic source for elevated Pb and Cd soil concentrations, whereas Cr and Ni soil concentrations were influenced by both natural and anthropogenic factors. Furthermore, the relatively high Pb concentrations in the plant tissues implied the role of car exhaust in introducing this pollutant into the environment. Even though the environmental risk of HMs in the studied area currently appears to be low, preventing the adverse impacts of cement production in this area requires further precautions. https://aet.irost.ir/article_978_c7e68b7083599fe5af2531a8c45feda8.pdfIranian Research Organization for Science and TechnologyAdvances in Environmental Technology2476-66745420191001Three-dimensional simulation of microcapillary and microchannel photo reactors for organic pollutant degradation from contaminated water using computational fluid dynamics22923798110.22104/aet.2020.4036.1203ENElham SadatBehinehDepartment of Chemical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, IranAli RezaSolaimany NazarDepartment of Chemical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, IranMehrdadFarhadianDepartment of Chemical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, IranFayazehRabanimehrDepartment of Chemical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, IranJournal Article20200301A three-dimensional (3D) simulation of four photocatalytic microreactors is performed using mass and momentum balance equations. The simulated results are validated with the available experimental data for the photocatalytic removal of methylene blue (MB) in two microcapillaries as well as dimethylformamide (DMF) and salicylic acid (SA) in two microchannels. In the surface layers of the microreactor, a photo removal reaction takes place, and the kinetic rates are described by the Langmuir-Hinshelwood (L-H) model. The Damköhler number for these microreactors is less than one, which indicates that the mass transfer rate is limited by the reaction rate. The numerical study and kinetic constants determination are carried out by using computational fluid dynamic techniques. The 3D model<em>predictions</em>are in<em>good agreement</em>with the available<em>experimental data</em> sets. The results of the parametric study show that by increasing the microreactor length from 50 to 90mm, the removal efficiency improves from 76% to 93%. Moreover, the removal rate is increased by about 40% by reducing the microchannel depth from 500 to 100 .https://aet.irost.ir/article_981_9af3e3d1d5f1e5d3cb2f577243dbc024.pdfIranian Research Organization for Science and TechnologyAdvances in Environmental Technology2476-66745420191001Analysis of Occupational Hazards and Lateral Environmental Pollution in the Construction Phase of Yadavaran Oil Field23924998510.22104/aet.2020.4324.1219ENHosseinVahidiEnvironment Department, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, IranAminPadashDepartment of Industrial Management, Faculty of Management and Economic, Tarbiat Modares University, Tehran, IranRamezanHeydariFaculty of Environment, University of Tehran, Tehran, IranJournal Article20200727Occupational hazards in the petroleum industry have always been among the major problems in the various phases of construction and installation, which sometimes cause environmental damage. The present study aims to evaluate the risk of occupational accidents in the petroleum industry in the construction phase (2010-2015) in one of the largest oil fields in Iran, namely the Yadavaran Oil Field in Khuzestan Province, and also discuss the lateral environmental damage. The environmental damage such as air, soil, and water pollution caused by occupational accidents were identified, and the distribution and type of activity were analyzed. For this purpose, the Failure Mode and Effects Analysis (FMEA) model was applied to evaluate the risk of occupational accidents. A total of 47 occupational accidents were identified during the 6-year construction phase of this oil field. The data was collected and underwent statistical analysis and risk assessment based on the location and hazards clustering, which is the main novelty of the article. According to the results, the average number of risk priorities for the observed occupational accidents was 212. Also, the occupational accidents were categorized by the type of accidents, and several corrective measures suitable for each type of accident were suggested. Based on these suggestions, the corrective Risk Priority Number (RPN) was expected to be about 133.2. As a result of these corrections, the risk reduction was expected to be 37% of the initial value. The changes introduced were low-cost, continuous, and periodic measures with positive effects on this oil field. https://aet.irost.ir/article_985_8ac75b32c705ba67ddba952f6071a676.pdf