Journal
ENVIRONMENTAL SCIENCE & TECHNOLOGY
Volume 52, Issue 20, Pages 11728-11734Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.est.8b02172
Keywords
-
Categories
Funding
- National Natural Science Foundation of China [21477060]
- Major Science and Technology Program for Water Pollution Control and Treatment in China [2017ZX07202001]
Ask authors/readers for more resources
Hexafluoropropylene oxide dimer acid (HFPO-DA, ammonium salt with trade name: GenX) has been recently detected in river water worldwide. There are significant concerns about its persistence, and potential adverse effects to the biota. In this study, the degradability of of GenX by typical advanced redox technologies (UV/persulfate and UV/sulfate) is investigated. Results demonstrate that <5% GenX is oxidized after 3 h in UV/persulfate system, which is much lower than similar to 27% for PFOA. In comparison, GenX can be readily degraded and defluorinated by hydrated electron (e(aq)(-)) generated by UV/sulfite system. Specifically, GenX is not detectable after 2 h, and >90% of fluoride ion is recovered 6 h later. This is attributed to the accumulation and subsequent degradation of CF3CF2COOH and CF3COOH, which are stable intermediates of GenX degradation. Mechanistic investigations suggest that the etheric bond in the molecule is a favorable attack point for the e(aq)(-). Such finding is corroborated by quantum chemical calculations. The side CF3- at the alpha-carbon probably acts as an effective barrier that prevents GenX from being cleaved by SO4 center dot- or OH center dot at its most sensible point (i.e. the carboxyl group). This study illustrates that reduction by UV/sulfite might be a promising technology to remove GenX from contaminated water.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available