Biochar as a sustainable solution for per- and polyfluoroalkyl substances (PFAS) Removal: Progress, Challenges, and Future Horizons

Abstract

The use of fluorinated compounds in household and industrial products is a critical concern since it contributes to the contamination of water sources on a larger scale. Per- and polyfluoroalkyl substances (PFAS) are regarded as ‘forever chemicals’ due to their high chemical stability. Biochar is widely recognized as a sustainable adsorbent material for successful adsorption of these PFAS from aqueous environments, owing to its low-cost and environmentally feasible nature. This review discussed the recent trends in PFAS adsorption from water using biochar and its derived composites. The influence of various parameters such as contact time, temperature, concentration of adsorbents, and pH of the adsorption environment is critically discussed. The detailed mechanisms of PFAS removal using these biochar-based adsorbents are discussed. The application of biochar adsorbents in real/ simulated environments and their successful regeneration are thoroughly discussed to reflect the efficacy and sustainability of these adsorbents. Furthermore, key challenges in PFAS removal using biochar adsorbents are explored, and future research directions are outlined to address existing gaps in the literature.