Effect of carbon chain length and functional group on decomposition pathway of perfluorinated organic acids
GU Yu-rong1, LI Xu2, ZHU Jia1, DONG Zi-jun1, LI Xian-li1
1. School of Construction and Environmental Engineering, Shenzhen Polytechnic, Shenzhen, 518055, China; 2. Shenzhen Shenshui Longhua Water Co. Ltd, Shenzhen 518109, China
Abstract：Effect of carbon chain length and functional group on decomposition of perfluorinated organic acids by the high intensity UV/sulfite system was investigated in this study. Typical perfluorinated organic acids, such as PFOA and PFOS, were selected to reveal their decomposition mechanisms. The results showed five kinds of perfluorinated organic acids were efficiently decomposed in this system, and their decomposition rate increased with increase of carbon chain length. Functional group played an important role in decomposition of perfluorinated organic acids. Decomposition rate of perfluorocarboxylic acids was obviously faster than perfluorosulfonic acids. Decomposition of perfluorocarboxylic acids started from the fluorine atom at α-position bonding with carboxyl, and then underwent decomposition with stepwise elimination of CF2 to form short chain perfluorocarboxylic acids. Desulfonation, defluorination at α position and centermost C-C bond scission were three main decomposition pathways of perfluorosulfonic acids.
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