AmphoRes™ performance for the removal of long- and short-chain PFAS as a multi-regenerable ion exchange resin

Regulation of per- and polyfluoroalkyl substances (PFAS) has become increasingly prominent in recent years, driven by health concerns over contaminated water and solids resulting from the widespread use of these persistent pollutants in billions of products. While ion exchange (IX) resins remain top-performing for PFAS removal from water, key limitations persist: restricted bed volumes (BV) and relatively rapid breakthrough for short chain PFAS, single-use designs, ecologically harmful regeneration chemicals that can be difficult to manage, high costs, and PFAS recovery challenges. This study introduces AmphoRes™, an IX resin that is regenerable and was specifically designed and developed as a potential alternative to overcome these constraints. Its pH-switchable surface charge enables efficient adsorption-desorption of PFAS across multiple regeneration cycles using minimal alkaline/acidic solutions, eliminating organic solvents or concentrated salts. Physicochemical characterization confirms that AmphoRes™ exhibits a uniform and spherical morphology, stability, and satisfies critical design requirements for industrial-scale production. Rapid small-scale column tests (RSSCTs) on groundwater collected from Orange County Water District (OCWD) demonstrated exceptional PFAS removal performance. After six regeneration cycles, 50% breakthrough exceeded cumulative BV 50 of 473,000 for PFOA (long chains), 443,000 BV for PFBS, 256,000 BV for PFBA, and 273,000 BV for PFPeA (short chains). The resin concurrently adsorbs heavy metals (Fe, Mn, Al, Cr, Co), while exhibiting low affinity for monovalent/divalent ions (Na, K, Ca, Mg). These results position AmphoRes™ as a sustainable, high-capacity solution for PFAS removal, combining industrial robustness with eco-friendly regeneration making it a potential product.