Degradation of PFOA with a nanosecond-pulsed plasma gas-liquid flowing film reactor

A continuous gas-liquid flowing film reactor with a nanosecond-pulsed power supply was utilized for the degradation of perfluorooctanoic acid (PFOA) as assessed by fluoride (F-) formation. PFOA, 50 mg/L, dissolved in deionized water was supplied at 2 ml/min with an argon carrier gas. The liquid phase was analyzed for F- using ion chromatography. The power supply pulse frequency (f) was varied between 0.25- and 10-kHz using a constant 16-kV input voltage and 40-ns pulse width. The highest F- production rate ( N F -), 1.57 x 10(-8) mol/s, occurred at 5 kHz whereas the highest efficiency of F- production ( E Y F -), 9.12 x 10(-9) mol/J, was found at 0.25 kHz.