Mehrdad Hajian; Mohammad Rostamizadeh; Federico Galli
Abstract
Catalysis for environmental remediation is becoming of paramount importance as industrial and urban activities multiply, and by-products contaminate soils and wastewater. Effluents from industrial and urban activities have led to many environmental problems involving water contamination. Here, we propose ...
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Catalysis for environmental remediation is becoming of paramount importance as industrial and urban activities multiply, and by-products contaminate soils and wastewater. Effluents from industrial and urban activities have led to many environmental problems involving water contamination. Here, we propose a new iron-incorporated metal-organic framework (MOF) photocatalyst to decontaminate water. The nanocatalyst was synthesized by the solvothermal method, and Fe was added to the structure as a promoter and active phase. In this study, we examined the degradation of methylene blue (MB) as a cationic azo dye. The nanocatalysts were characterized by XRD, FE-SEM, BET, NH3-TPD, and FTIR techniques. The results showed high crystallinity, a large specific surface area, and a uniform promoter distribution. At a pH = 9, a catalyst amount of 110 mg and an initial MB concentration in the effluent of 2 ppm resulted in the highest removal percentage (98 %). The kinetic analysis provided a quasi-first-order model that reasonably matched the experimental data (R2 = 95 %). The results verified the catalyst’s great capability for efficient and fast MB removal in 60 minutes of photocatalytic processing.
Mahmood Hajiani; Efat Ezami; Mohammad Reza Rezaei
Abstract
Fe3O4/ ZnO/Ag magnetic nanocomposite was synthesized for the first time and its ability was evaluated for photocatalytic degradation of albumin in aqueous solutions under UV-A light. The resulting nanoparticles were then characterized using X-ray diffraction (XRD), scanning electron microscopy (FESEM), ...
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Fe3O4/ ZnO/Ag magnetic nanocomposite was synthesized for the first time and its ability was evaluated for photocatalytic degradation of albumin in aqueous solutions under UV-A light. The resulting nanoparticles were then characterized using X-ray diffraction (XRD), scanning electron microscopy (FESEM), vibration magnetometer (VSM), and Fourier infrared (FTIR). The effects of some parameters such as pH, initial albumin concentration, catalyst concentration, and temperature were also investigated in the photodegradation of albumin. The results showed that the maximum removal of albumin was obtained at pH 9, catalyst concentration of 0. 5 g/l, initial albumin concentration of 150 mg/l, and room temperature in 90 min. Under the optimum conditions, the total amount of organic carbon (TOC) was 56%. Kinetic degradation experiments followed the pseudo-first-order kinetic model with a constant rate (k) of 0.0255 min-1. Therefore, due to the high performance of Fe3O4/ ZnO/Ag magnetic nanocomposite in the degradation of albumin as well as its easy synthesis and separation with an external magnetic field, it can be used as a suitable and environmentally friendly catalyst for the degradation of organic and resistant pollutants in the wastewater.
Sumon Chakrabarty; Md. Anas Mahmud; Mosummath Hosna Ara; Shovon Bhattacharjee
Abstract
The present study aimed to synthesize copper oxide (CuO) nanoparticles (NPs), which were used as an adsorbent for the sequestration of Iron (Fe) (III) ion from aqueous solution. The synthesized NPs were characterized with the help of X-ray diffraction (XRD) spectroscopy, Field Emission scanning electron ...
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The present study aimed to synthesize copper oxide (CuO) nanoparticles (NPs), which were used as an adsorbent for the sequestration of Iron (Fe) (III) ion from aqueous solution. The synthesized NPs were characterized with the help of X-ray diffraction (XRD) spectroscopy, Field Emission scanning electron microscopy (FESEM), and Energy-dispersive X-ray spectroscopy (EDS). The SEM and XRD analyses indicated the average size of CuO NPs were ~25 nm with a rod-like shape. Based on the batch experiments the maximum adsorption observed at pH 9 with removal efficiency 98.38%, initial metal ion concentration of 10 ppm, and contact time 60 min. This study also revealed that adsorption capacity increases when the concentration of adsorbents decreases. To specify the adsorption characteristics of CuO NPs, the adsorption equilibrium data were treated with Langmuir and Freundlich models, which demonstrated that the removal of Fe (III) ions was mostly favored by the physical process followed by the multilayer adsorption on the heterogeneous surface of the adsorbents. Finally, this study concludes that CuO NPs could be used as a promising material for the removal of Fe(III) ion from aqueous Solution.
Shahryar Jafarinejad
Abstract
Large quantities of oily wastewaters can be generated from the activities and processes in the petroleum industry which draining of these effluents not only pollutes the environment but also reduces the yield of oil and water. Therefore, development of treatment processes for petroleum industry wastewaters ...
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Large quantities of oily wastewaters can be generated from the activities and processes in the petroleum industry which draining of these effluents not only pollutes the environment but also reduces the yield of oil and water. Therefore, development of treatment processes for petroleum industry wastewaters is vital in order to prevent serious environmental damage and provide a source of water for beneficial use. Reverse osmosis (RO) can be the most common membrane process used for desalination from oily wastewater and can produce water suitable for reuse at the petroleum industry. In this study, the application of RO technology for the petroleum industry wastewater treatment in different laboratory, pilot, field, and industrial scales have been reviewed. In addition, membrane fouling control, performance efficiency, treatment system configurations, pretreatment methods, quality of treated water, and economic issues have been investigated. With mixtures as complex as petroleum industry wastewaters, membrane fouling becomes a significant hurdle to implement the RO-based purification system. Operating the system within the critical flux range or adding chemicals, and/or pretreatment can usually control membrane fouling. Salt rejection of RO membranes can be 99% or higher.
Samad Sabbaghi; Fateme Doraghi
Abstract
In this study, considering the importance of protecting the environment and preventing the pollution caused by industrial plants, a nanocomposite each component thereof is capable of removing the desired combination to solve this problem has been produced. To achieve this goal, ZnO/SnO2nanocomposite ...
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In this study, considering the importance of protecting the environment and preventing the pollution caused by industrial plants, a nanocomposite each component thereof is capable of removing the desired combination to solve this problem has been produced. To achieve this goal, ZnO/SnO2nanocomposite was synthesized using the co-precipitation method. The characterization of this nanocomposite was conducted by DLS, XRD, FTIR and SEM. The nanocomposite size was about 15nm. Several parameters such as the initial concentration of the wastewater, as well as the amount of catalyst and time were investigated. The reduction of the particle size due to an increase in the surface area of the nanocomposite increased the amount of decolorization. For all the performed experiments, the dye removal rate was 100% and the difference was to do with the time of the complete removal of methylene blue. A decrease in the concentration of methylene blue in the range of the tested concentrations reduced the decolorization, and by increasing the amount of nanocomposite in the range of the tested values, a decline in decolorization was observed.