Degradation and mechanism of hexafluoropropylene oxide dimer acid by thermally activated persulfate in aqueous solutions

Hexafluoropropylene oxide dimer acid (HFPO-DA), an alternative of perfluorooctanoic (PFOA), has been detected frequently in environmental media worldwide. It reported that HFPO-DA is equal to or more toxic than PFOA, as well recalcitrant degradation. In this study, the efficient degradation was achieved by thermally activated persulfate (TAP) system, but influence co-contaminants field can be significant. The pathways were proposed through integrated approach experiment and density functional theory (DFT) calculations. CF3CF2COO? CF3COO?, stable intermediates identified ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-Q-TOF-MS). Electron transfer, decarboxylation, H abstraction, HF elimination using H2O a catalyst hydrolysis occurred different steps process, with –COO? initial oxidative site attacked SO4?. addition, acute toxicity assessment for TAP system performed Escherichia coli suggested degraded level having no adverse effect on growth E. coli, formed. Overall, work provides insights contamination system.