Advances in waste-derived functional materials for PFAS remediation

Per- and polyfluoroalkyl substances (PFAS) are synthetic organofluoride compounds, widely used in industries since the 1950s for their hydrophobic properties. PFAS contamination of soil and water poses significant environmental and public health risks due to their persistence, chemical stability, and resistance to degradation. The Chemical Abstracts Service catalogs approximately 4300 PFAS globally. Research in various regions such as North America, Asia, Europe, and remote polar zones has revealed the accumulation of perfluorooctane sulfonate (PFOS) in the tissues of various animal species, with concentrations reaching up to 1900 ng/g in aquatic species like dolphins and whales. Researchers have employed various remediation techniques such as solvent extraction, ion exchange, precipitation, adsorption, and membrane filtration, each of which has its drawbacks. Adsorption, particularly using waste-derived functional materials like biochar, is emerging as a promising method for PFAS remediation due to its cost-effectiveness and sustainability. For example, waste timber-derived biochar exhibits adsorption efficiency comparable to commercial activated carbon. This review highlights advancements in using agricultural, industrial, and biological waste-derived materials for sustainable PFAS remediation. We discuss innovative modification techniques like hydrothermal synthesis, pyrolysis, calcination, co-precipitation, the sol–gel method, and ball milling. The study also examines adsorption mechanisms, factors affecting adsorption efficiency, and the technological challenges in scaling up waste-derived material use. It aims to explore developments, challenges, and future directions for using these materials for efficient PFAS remediation and contributing to sustainable environmental cleanup solutions.