Shahryar Jafarinejad; Mohammad Faraji; Zohreh Norouz; Javad Mokhtari-Aliabad
Abstract
Even at low levels, heavy metals are toxic and can damage living things. They do not break down or decompose and tend to build up in plants, animals, and people causing health concerns. Magnetic nanoparticles (MNPs) can be considered as potential adsorbents for the removal of cadmium (Cd2+) from aqueous ...
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Even at low levels, heavy metals are toxic and can damage living things. They do not break down or decompose and tend to build up in plants, animals, and people causing health concerns. Magnetic nanoparticles (MNPs) can be considered as potential adsorbents for the removal of cadmium (Cd2+) from aqueous solutions because of their high surface area and the combined effect of adsorption and separation under external magnetic fields. In this study, a novel sulfur-modified magnetic nanoparticle was applied as an adsorbent for the removal of Cd2+ ions from aqueous solutions. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). The effects of pH, contact time, and initial concentration of Cd2+ on the removal efficiency of it were investigated in batch adsorption experiments. The equilibrium data fitted the Langmuir isotherm model better than the Freundlich isotherm model, and they were well explained in terms of pseudo-second-order kinetics. The maximum monolayer capacity qm and KL the Langmuir constant were calculated from the Langmuir as 5.1867 mg/g and 0.1562 L/mg, respectively.
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.