Degradation of Perfluoroalkyl Acids under 222 nm Irradiation in the Presence and Absence of Sulfite

-mediated destruction, not true direct photolysis. To compare the effectiveness of 222 nm KrCl* lamps with 254 nm, the UV/sulfite system was tested on two complex water matrices: (i) a reverse osmosis concentrate (ROC) spiked with short- and long-chain perfluoroalkyl acids and (ii) an aqueous film forming foam (AFFF). The extent of PFAS destruction in these complex matrices was greater for 222 nm irradiation relative to 254 nm by up to 6-fold when normalized to incident fluence. Overall, this study provides fundamental insight into the UV-based degradation of perfluoroalkyl acids at 222 nm and suggests that KrCl* lamps may provide improved performance compared to conventional 254 nm sources in UV/sulfite ARP for PFAS destruction in complex water matrices.