Complete aqueous defluorination of PFAS in aqueous film-forming foam (AFFF) by pulsed electrolysis with tailored potential modulation

Abstract

Per- and polyfluoroalkyl substances (PFAS) are harmful and persistent global water contaminants. AFFF, a foam-forming aqueous mixture used for firefighting, is a major source of PFAS pollution and challenging to defluorinate. We report the complete photo-assisted electrocatalytic defluorination of PFAS in AFFF with nonprecious materials. The high salt content in the aqueous LiOH electrolyte prevented foaming. Pulsed electrolysis with tailored potential modulation balanced anodic fluoride removal and the adsorption of unreacted anionic PFAS. Our findings demonstrate the effectiveness of pulsed electrocatalysis in defluorinating persistent PFAS in AFFF.