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.

中文翻译：

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在用氯或臭氧进行水消毒时，两性离子和阳离子前体化合物会生成PFOA和PFOS。

全氟辛酸酯（PFOA）和全氟辛烷磺酸（PFOS）是阴离子有机污染物，在环境中广泛存在。由于它们在环境中的持久性及其毒性和生物蓄积性，它们已成为全球关注的问题。在这项研究中，我们证明了在用氯或臭氧进行常规饮用水消毒期间，PFOA，PFOS或两者均由四种两性离子/阳离子多氟烷基酰胺（FA）和磺酰胺（FS）化合物组成。FA化合物很容易被氯降解，并主要通过霍夫曼型重排而主要转化为PFOA。FS化合物对氯的反应性低得多；FS产生的PFOS并不重要。臭氧处理期间，所有四种FA和FS化合物均迅速降解，生成PFOA，PFOS，以及一些不经常报告的产品，这些产品的化学结构已通过高分辨率质谱法确认或初步提出。FS在臭氧化过程中同时生成PFOS和PFOA，PFOA的产率甚至比FA更高。这项研究的结果可能为FAs和FSs的降解机理提供重要的见解，并阐明它们对天然和工程系统中PFOA和PFOS的二次形成的贡献。