Biochar and biochar composites for poly- and perfluoroalkyl substances (PFAS) sorption

PFAS can be concentrated in the food chain and continuous ingestion from water could cause a buildup concentration in humans. PFAS have caused serious health effects even at low parts per billion levels of exposure (> 70 ng/L). The removal of PFAS from drinking/wastewater and agricultural systems has recently gained tremendous attention. Biochar is ubiquitous and attractive for PFAS treatment applications in remote communities where it is logistically infeasible to install commercial adsorbents. This chapter gives an up-to-date summary of laboratory and pilot-scale PFAS adsorption studies using biochar adsorbents. Covered topics include biochar tailoring, characterization, sorption benchmarks (pH effects, kinetics, isotherms, and thermodynamics), PFAS applied water treatment (regeneration, competitive effects, column studies, and pilot plants) sorption mechanisms.