Per-and polyfluoroalkyl substances (PFAS) are synthetic chemicals used since the 1940s. Their ubiquitous presence in the environment, significant toxicity, and persistence have raised growing public concerns. Aqueous film-foaming foam (AFFF) was identified as the major culprit responsible for the elevated PFAS concentration in the receiving water and soil of manufacturing sites, airports, and military fire training areas. The most urgently needed proactive solution to curb new PFAS contamination from using AFFF is the disposal of the existing chemical stockpile. The incineration of AFFF is facing regulatory challenges due to concerns about the emission of incomplete combustion products and greenhouse gas. Alternative non-thermal technologies enabling near-complete defluorination (i.e., conversion of organofluorine on PFAS to fluoride (F -)), in addition to degradation of parent PFAS compounds, are desired to meet the zero PFAS pollution goal. However, deep defluorination of even a single type of PFAS is challenging. For instance, the maximum defluorination efficiencies of treating perfluorooctane sulfonic acid (PFOS) by electrochemical oxidation, UV-sulfite photoreduction, and alkaline-assisted heat treatment are below 80%. The deep defluorination of AFFF, a mixture of concentrated PFAS with co-existing solvents and surfactants, is a next-level challenge that has been inadequately addressed.