Adsorptive removal of per- and polyfluoroalkyl substances: From conventional porous materials to metal-organic frameworks and covalent organic frameworks

2 Per- and polyfluoroalkyl substances (PFAS) are a widespread class of anthropogenic environmental contaminants that have garnered increasing global concerns due to their potential long-term impacts on ecosystems and human health. The historical use of aqueous film-forming foams (AFFF) containing PFAS has been identified as a major contamination source, leading to widespread pollution of aquatic systems, including surface water and groundwater resources. Adsorption, a conventional water treatment method, provides a cost-effective, operationally simple, and technologically mature approach for PFAS removal. However, conventional adsorbents such as ion-exchange resins, zeolite and activated carbons, often show limited adsorption capacities and/or slow adsorption kinetics. In contrast, emerging porous materials—particularly metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs)—have demonstrated significant improvements in efficiency of PFAS removal, offering new insights for advancing technologies for PFAS remediation. This review systematically evaluates current methodologies and recent advancements in PFAS removal from drinking water and wastewater through adsorption by state-of-the-art porous materials.