Application of Response Surface Methodology for the Optimization of Operating Conditions of a Self‐Pulsing Discharge (SPD) Plasma Reactor for the Degradation of Perfluorooctanoic Acid (PFOA) in Water

Abstract

This study explores atmospheric plasma as a novel approach for the degradation of persistent per‐ and polyfluoroalkyl substances (PFAS) in contaminated waters. Using response surface methodology and Box–Behnken design, the performance of the self‐pulsing discharge (SPD) reactor was optimized by adjusting the following independent factors: input power, plasma area‐to‐liquid volume ratio, and argon bubbling time. Optimization was assessed using four specific indicators: kPFOA and G50, for the process velocity and energy efficiency, respectively; kPFOA/kPFHpA and ΣPFAS/C0, both for the presence of PFAS in the treated water for the process products. Under the optimized operating conditions, residual PFAS summed up to only 2.4% of the carbon initially present as PFOA, and a remarkable G50 value of (523 ± 10) mg/kWh was obtained.