Environ. Sci. Technol. Lett.5, 382-388, 2018.

PFOA and PFOS Are Generated from Zwitterionic and Cationic Precursor Compounds During Water Disinfection with Chlorine or Ozone

Link: https://pubs.acs.org/doi/abs/10.1021/acs.estlett.8b00266

中文摘要：Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) 是全球关注的持久性有机污染物，二者在自然界和常规水处理过程中虽然不能被降解，但本研究发现了其在常规水处理消毒和氧化单元可以二次生成，并对从生成机理进行了阐述。

Abstract:

Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) are anionic organic pollutants, which are widespread in the environment. They have become a global concern due to their persistence in the environment as well as their toxicity and bioaccumulative properties. In this study, we demonstrate that PFOA, PFOS, or both are produced from a group of four zwitterionic/cationic polyfluoroalkyl amide (FA) and sulfonamide (FS) compounds during conventional drinking-water disinfection with chlorine or ozone. FA compounds were readily degraded by chlorine and converted primarily to PFOA, likely by a Hofmann-type rearrangement. FS compounds were much less reactive toward chlorine; the generation of PFOS from the FSs was not significant. All four FA and FS compounds were degraded rapidly during ozonation, generating PFOA, PFOS, and a number of infrequently reported products for which chemical structures were either confirmed or tentatively proposed using high-resolution mass spectrometry. FSs generated both PFOS and PFOA during ozonation with the yield of PFOA even higher than that from the FAs. The results of this study may provide important insight into the degradation mechanisms of FAs and FSs and shed light on their contribution to the secondary formation of PFOA and PFOS in natural and engineered systems.