Molecular characterization of transformation and halogenation of natural organic matter during the UV/chlorine AOP using FT-ICR mass spectrometry  

作　　者：Xiaoxue Ruan Yingying Xiang Chii Shang Shuangshuang Cheng Jingfu Liu Zhineng Hao Xin Yang 

机构地区：[1]School of Environmental Science and Engineering,Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology,Sun Yat-sen University,Guangzhou 510275,China [2]Department of Civil and Environmental Engineering,The Hong Kong University of Science and Technology,Hong Kong,China [3]Hong Kong Branch of Chinese National Engineering Research Center for Control&Treatment of Heavy Metal Pollution,The Hong Kong University of Science and Technology,Hong Kong,China [4]State Key Laboratory of Environmental Chemistry and Ecotoxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China

出　　处：《Journal of Environmental Sciences》2021年第4期24-36,共13页环境科学学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2017YFE0133200);the National Natural Science Foundation of China(Nos.21876210 and 21806173);the Guangdong Provincial Science and Technology Planning Projects(No.2019A050503006);Hong Kong RGC(Nos.16206416 and T21-604/19-R)。

摘　　要：UV/chlorine process,as an emerging advanced oxidation process(AOP),was effective for removing micro-pollutants via various reactive radicals,but it also led to the changes of natural organic matter(NOM)and formation of disinfection byproducts(DBPs).By using negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS),the transformation of Suwannee River NOM(SRNOM)and the formation of chlorinated DBPs(Cl-DBPs)in the UV/chlorine AOP and subsequent post-chlorination were tracked and compared with dark chlorination.In comparison to dark chlorination,the involvement of Cl O·,Cl·,and HO·in the UV/chlorine AOP promoted the transformation of NOM by removing the compounds owning higher aromaticity(AI mod)value and DBE(double-bond equivalence)/C ratio and causing the decrease in the proportion of aromatic compounds.Meanwhile,more compounds which contained only C,H,O,N atoms(CHON)were observed after the UV/chlorine AOP compared with dark chlorination via photolysis of organic chloramines or radical reactions.A total of 833 compounds contained C,H,O,Cl atoms(CHOCl)were observed after the UV/chlorine AOP,higher than 789 CHOCl compounds in dark chlorination,and one-chlorine-containing components were the dominant species.The different products from chlorine substitution reactions(SR)and addition reactions(AR)suggested that SR often occurred in the precursors owning higher H/C ratio and AR often occurred in the precursors owning higher aromaticity.Post-chlorination further caused the cleavages of NOM structures into small molecular weight compounds,removed CHON compounds and enhanced the formation of Cl-DBPs.The results provide information about NOM transformation and Cl-DBPs formation at molecular levels in the UV/chlorine AOP.

关 键 词：UV/chlorine AOP Disinfection byproducts(DBPs) Natural organic matter(NOM) FT-ICR MS Water treatment 

分 类 号：TU991.2[建筑科学—市政工程]