Sustainable ion exchange-based remediation of per- and polyfluoroalkyl substances; recent progress and future prospects

This review presents recent advances and future directions in sustainable ion exchange (IEX)-based remediation of per- and polyfluoroalkyl substances (PFAS) in wastewater and freshwater. IEX resins demonstrate high efficiency in PFAS removal, either as standalone solutions or in combination with complementary techniques such as membrane filtration or activated carbon. Despite their effectiveness, challenges remain in enhancing PFAS selectivity, improving resin regenerability, and managing end-of-life options for spent resins and concentrated PFAS streams. In the context of PFAS selectivity, future research directions include investigating hydrophobic and hydrogen-bonding interactions in PFAS uptake, developing PFAS-selective resins, and examining the effects of inorganic anions on short-chain PFAS removal. Additionally, in the areas of regeneration and disposal methods for PFAS-laden IEX resins and PFAS-containing regeneration streams, innovative approaches such as thermal volatilization, oxidative treatments, advanced sonochemical techniques, and plasma treatments hold promise. Advancing these methods will be crucial for closing knowledge gaps and developing next-generation solutions for IEX-based PFAS remediation.