Research Progress on Adsorptive Removal Technologies for Per- and Polyfluoroalkyl Substances in Water

PFAS have become emerging contaminants of global concern due to their strong C-F bonds, high environmental persistence, mobility, and potential toxicity. Adsorption is considered one of the most practical technologies for PFAS removal from water because of its mild operating conditions, mature process configuration, and applicability to low-concentration contaminants. This review summarizes recent progress in the adsorptive removal of PFAS from aqueous environments. The main adsorption mechanisms, including hydrophobic interaction, electrostatic attraction, ion exchange, pore filling, coordination interaction, and molecular aggregation, are discussed. Typical adsorbent materials, including activated carbon, ion exchange resins, metal-organic frameworks, biochar, and covalent organic frameworks, are further reviewed with emphasis on their adsorption behavior, material characteristics, performance differences, and application limitations. Activated carbon and ion exchange resins remain the most practical options for engineering applications, but their performance for short-chain PFAS removal and the management of spent adsorbents remain challenging. Metal-organic frameworks and covalent organic frameworks exhibit high structural tunability and promising selectivity, while their stability, cost, scalability, and long-term operation still require further improvement. Biochar shows advantages in low cost and resource utilization, but its adsorption performance is strongly affected by feedstock and preparation conditions. Future studies should focus on real water matrices, low-concentration and mixed-PFAS systems, dynamic column operation, adsorbent regeneration, concentrate treatment, and life-cycle environmental impacts, thereby supporting efficient, economical, and sustainable control of PFAS-contaminated water.