Occurrence and treatment of emerging contaminants in water: A comprehensive review

The occurrence of highly polar, potentially persistent and mobile organic micropollutants (OMP) in aquatic environments poses a significant threat to water resources and drinking water suppliers. Several OMP were identified in water bodies for the first time due to the improvement in analytical techniques. This review summarizes the occurrence of recently detected OMP, their fate, and treatment approaches for their effective removal. Additionally, this review examines current literature to evaluate the efficacy of different water treatment methods including managed aquifer recharge (MAR), adsorption methods (including carbon-based adsorbents, metal-organic frameworks (MOF), and ion exchange resins), and advanced oxidation processes (AOP) for the removal of OMP. The chosen techniques demonstrate efficacy in removing various OMP from water. The removal of various industrial chemicals and pharmaceuticals through bank filtration has been reported for the first time. Adsorbents, such as ion exchange resins and metal-organic frameworks (MOF), have demonstrated substantial removal efficiencies for several OMP, including per- and polyfluoroalkyl substances (PFAS) and other organic contaminants. Enhanced removal of both long- and short-chain PFAS was observed with ion exchange resins compared to other adsorbents. MOF materials are reported to exhibit high adsorption capacity and rapid kinetics for OMP removal in aqueous solutions. AOP effectively eliminates several emerging pollutants such as pharmaceuticals and PFAS. This review helps in identifying the best available technology for specific contaminants under defined conditions.