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The scarcity of freshwater resources in many regions of the world has contributed to the emergence of various technologies for treating and recovering wastewater for reuse in industry, agriculture, and households. Deep wastewater treatment from oils and petroleum products is one of the difficult tasks that must be solved. Among the known technologies, UF membranes have found wide industrial application with high efficiency in removing various pollutants from wastewater. It is shown that the search for and development of highly efficient, durable, and resistant to oil pollution UF membranes for the treatment of oily wastewater is an urgent research task. The key parameters to improve the performance of UF membranes are by enhancing wettability (hydrophilicity) and the antifouling behavior of membranes. In this review, we highlight the using of ultrafiltration (UF) membranes primarily to treat oily wastewater. Various methods of polymer alterations of the UF membrane were studied to improve hydrophilicity, the ability of antifouling the membrane, and oil rejection, including polymer blending, membrane surface modification, and the mixed membrane matrix. The influence of the type and composition of the hydrophilic additives of nanoparticles (e.g., Multiwall carbon nanotubes (MWCNT), graphene oxide (GO), zinc oxide (ZnO), and titanium dioxide (TiO2), etc.) was investigated. The review further provides an insight into the removal efficiency percent.

This study highlights the groundwater hydrogeochemical characteristics and processes (hydrochemistry characteristics, ion exchange, and salinization) and quality suitability assessment for irrigation purposes from five wells in the Greenbelt area located in northwestern Al-Najaf Governorate, Iraq. The suitability of groundwater for irrigation was assessed based on the irrigation water quality index (IWQI) for thirteen parameters and groundwater quality indices such as total dissolved solids (TDS), electrical conductivity (EC), sodium adsorption ratio (SAR), soluble sodium percent (SSP), residual sodium carbonate (RSC), total hardness (TH), permeability index (PI), potential salinity (PS), Kelley’s ratio (KR), and magnesium hazard ratio (MHR). The IWQI’s average values ranged between 76–139. The results of IWQI for the first and second sampling sites showed values of 139 and 104, respectively, indicating that the groundwater was unsuitable and unsafe for irrigation. In contrast, the IWQI for the third, fourth, and fifth sites were 83, 97, and 76, respectively, indicating that the groundwater was safe and possibly used for irrigation. The EC, TDS, PS, and MHR indices were all found to be unsuitable for irrigation in all five sites, and the KR index was also found to be unsuitable for agricultural irrigation in about 80% of the sites, while it was found that the indices of SAR, SSP, RSC, PI, and TH for all sites were suitable and safe for irrigation. As a result of this study, it has been determined that groundwater in the study area is unsuitable for agricultural irrigation. For sustainable groundwater exploitation, it is advised that a continuous water-quality-monitoring program should be implemented, as well as the development of suitable management practices.

One of the most significant urban services is the carwash, which generates large amounts of wastewater containing a variety of pollutants, including sand, gravel, suspended solids, surfactants, oil products, diesel cleaners, etc., that may cause environmental pollution when transferred to the sewage system without any treatment. The effective treatment is crucial to prevent environmental pollution as well as to recycle the water source. Contaminants are removed from carwash effluent using a variety of treatment technologies. This review focuses on identifying and comparing efficiency of using advanced commercial and modified membrane filtration techniques, meeting discharge standard regulations, to treat carwash impurities, especially detergents/surfactants (anionic surfactant) and petroleum products (oil/grease). The results of this review indicate that ultrafiltration membrane (UF) is the most common membrane filtration technology for carwash wastewater treatment. Additionally, the adoption of traditional pre-treatment processes may be advantageous before utilization of membrane process for treating carwash wastewater; although conventional treatment processes can produce a high quality of effluent, they are less effective than membrane systems.

We present a survey devoted to the search and analysis of the scientific and technical literature and patent information on the use of biological methods for the extraction of valuable metals from the ash and slag wastes of thermal power plants and waste incineration plants operating on coals and shales. The physical and chemical properties of ash-and-slag wastes and their components are investigated. We also study specific features and problems of bioleaching of nonferrous and less-common (aluminum, vanadium, germanium, and gallium) metals and rare-earth elements from the ash-and-slag wastes.