Degradation of Perfluorooctanoic Acid by Reactive Species Generated through Catalyzed H₂O₂ Propagation Reactions

Abstract

Perfluorinated compounds, which are environmentally persistent and bioaccumulative contaminants, cannot currently be treated in the subsurface by <i>in situ</i> technologies. Catalyzed H₂O₂ propagation (CHP) reactions, which generate hydroxyl radical, hydroperoxide anion, and superoxide anion, were investigated for treating perfluorooctanoic acid (PFOA) as a basis for <i>in situ</i> chemical oxidation remediation of groundwater. Using 1 M H₂O₂ and 0.5 mM iron­(III), PFOA was degraded by 89% within 150 min. Hydroxyl radical does not react with PFOA, but systems producing only superoxide promoted 68% PFOA degradation within 150 min. In systems producing only hydroperoxide, the level of PFOA degradation was 80% over 150 min. The generation of near-stoichiometric equivalents of fluoride during PFOA degradation and the lack of detectable degradation products suggest PFOA may be mineralized by CHP. CHP process conditions can be adjusted during treatability studies to increase the flux of superoxide and hydroperoxide to treat PFOA, providing an easily implemented technology