Hydrogen-polarized vacuum ultraviolet photolysis system for enhanced destruction of perfluoroalkyl substances

• DOI: 10.1016/j.hazl.2022.100072
• Publication Date: 2022-11-08T17:53:41Z
• Authors: Gongde Chen; Sitao Liu; Qingyang Shi; Jay Gan; Bosen Jin; Yujie Men; Haizhou Liu
• Keywords: Solvated electron; Perfluorooctanoic acid; Hydroxyl radical

Reductive water treatment using hydrated electrons (eaq−) is a promising technology to destruct perfluoroalkyl substances; however, it faces challenges of slow reaction kinetics, undesirable chemical addition, and high energy consumption. Herein, we developed hydrogen (H2)-polarized photolysis system vacuum UV (VUV) light at 185 nm for reductive destruction perfluorooctanoic acid (PFOA) perfluorooctanesulfonic (PFOS). The 185-nm photons directly photolyzed H2O OH- into HO·, H·, eaq−. H2 elevated the quasi steady-state concentration eaq− 18 times in untuned VUV systems through eliminating scavenging effect dissolved oxygen converting hydroxyl radicals (HO·/O·-) polarization increased degradation PFOA from 10 % 95 defluorination 17 94 led 87 PFOS. pH impacted photon adsorption between shifted equilibrium H· eaq−, which an optimal 10.3 destruction. presence chloride sulfate enhanced production promoted H2-polarized produced levels clean constituents significantly reduced consumption PFAS under mild alkaline conditions.