Emerging developments in polymeric nanocomposite membrane-based filtration for water purification: A concise overview of toxic metal removal

The presence of toxic heavy metals (HMs) in water systems poses significant threats to both human health and the environment. Researchers worldwide have been actively exploring various technologies for HMs removal, and nanomaterial-based adsorption has emerged as a particularly promising approach. Nanomaterials like carbon nanotubes, graphene oxide, zeolites, and metal oxide nanoparticles have garnered attention due to their exceptional adsorption performance, which can be attributed to their high thermal/chemical stability, large surface area, and functional groups. However, the practical implementation of these nanomaterials faces challenges, i.e., recovering the adsorbents and the tendency of aggregation into larger particles. In recent years, the development of polymeric nanocomposite membranes has shown great potential for HMs removal. By incorporating nanomaterials into the polymer matrix, these membranes achieve a synergistic effect of filtration and adsorption, making them highly effective in removing HMs. This comprehensive review focuses on the latest findings regarding the performance of widely studied polymeric nanocomposite membranes. Specifically, it covers carbon-based, clay-based, zeolite-based, and metal/metal oxide-based nanocomposite membranes, discussing their HMs rejection rates, flux rates, and critical insights into fabrication strategies. Furthermore, the review addresses the current challenges and offers future perspectives for nanocomposite membranes. The aim of this review is to provide a comprehensive analysis of the recent advancements in polymeric nanocomposite membrane-based filtration for removing HMs from water. By presenting a detailed overview of the current state of research, limitations, and potential directions, this review serves as a valuable resource for researchers and practitioners in the field. It offers insights into the efficacy of these membranes and paves the way for further exploration in addressing the pressing issue of toxic metal contamination in water sources.