Electrochemical per- and polyfluoroalkyl substances (PFAS) removal from tap water: Proof-of-concept and laboratory scale pilot

The removal of per- and polyfluoroalkyl substances (PFAS) from water remains a major environmental challenge, particularly at low concentrations (~ µg L -1 ) and in mixtures containing both long- and short-chain variants. This study focuses on developing an effective PFAS removal process using electrochemistry. A proof-of-concept for the removal of fluorinated organic compounds and PFAS from a controlled, clean environment is first demonstrated, and the removal mechanisms are clarified. A laboratory-scale batch system for PFAS removal was then designed and tested. Under realistic conditions (PFAS concentrations ~ 10 µg L -1 in tap water), PFAS concentrations were reduced significantly (< 0.06 µg L -1 ) within a relatively short time (t ½ < 15 min) . A continuous stirred-tank reactor system was also developed to examine a continuous process. The effectiveness of this system was somewhat lower, resulting in higher PFAS levels (~ 0.1 µg L -1 ). The only exception in both batch and continuous processes is short-chained PFAS, which have relatively low removal efficiency (~ 20%). Overall, this study demonstrates an effective and quick method for PFAS removal, especially in batch mode, which can be further developed to enhance water quality. • Electrochemical methods remove PFAS from aqueous solutions. • PFAS mixtures can be removed at environmental levels. • A mechanism for PFAS (and FOC) removal is proposed. • PFAS removal is presented in batch and continuous processes.