Abstract: Systems and methods are provided for degrading PFAS in a semi-solid sample. The semi-solid sample includes PFAS molecules in a partially liquid solution. An electron donor, and optionally a surfactant, are introduced into the mixture, forming micelles. An electron donor associates with the micelle surface and releases hydrated electrons upon exposure to UV light to initiate the reductive defluorination reaction, resulting in fluoride, water, and simple carbon compounds.