Degradation of Low‐Concentration Perfluoroalkyl Substances With a Nonthermal Gas–Liquid Plasma Reactor

ABSTRACT A continuous gas–liquid flowing film reactor with nanosecond pulsed power, where plasma channels generated in argon propagate along the gas–liquid interface, was utilized to degrade aqueous solutions of perfluoroalkyl substances (PFAS). Perfluorooctanoic acid (PFOA) yielded maximum percentage degradations of 81.6% and 76.5% for the low (98 ± 29 ppt) and high (300 ± 30 ppt) concentrations, respectively, at 2 mL/min liquid flow and a pulse repetition frequency of 0.5 to 2 kHz. A mixture of perfluorocarboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs) was also degraded. Sequential multi‐pass treatments of PFOA with an initial concentration of 413 ± 142 ppt using 2 kHz resulted in 84.3% degradation in the first pass and no PFOA was detected after additional passes.