文献类型：期刊文献

英文题名：New insights into clopyralid degradation by sulfate radical: Pyridine ring cleavage pathways

作者：Yang, Xuerui[1];Ding, Xi[1];Zhou, Lei[1,2];Fan, Huan-huan[3,4];Wang, Xingbao[3,4];Ferronato, Corinne[5];Chovelon, Jean-Marc[5];Xiu, Guangli[1,2]

机构：[1]East China Univ Sci & Technol, Sch Resources & Environm Engn, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China;[2]Shanghai Inst Pollut Control & Ecol Secur, Shanghai 200092, Peoples R China;[3]Taiyuan Univ Technol, Training Base State Key Lab Coal Sci & Technol Jo, Taiyuan 030024, Peoples R China;[4]Taiyuan Univ Technol, Minist Sci & Technol, Taiyuan 030024, Peoples R China;[5]Univ Claude Bernard Lyon 1, Univ Lyon, IRCELYON, CNRS,UMR 5256, 2 Ave Albert Einstein, F-69626 Villeurbanne, France

年份：2020

卷号：171

外文期刊名：WATER RESEARCH

收录：;EI(收录号：20195007834312);WOS:【SCI-EXPANDED(收录号:WOS:000514748900008)】；

基金：This work was supported by the National Natural Science Foundation of China (No. 21806037).

语种：英文

外文关键词：Sulfate radical; Pyridine ring cleavage; Derivatization; Dissolved oxygen; DFT calculation

摘要：Contamination by herbicides such as clopyralid (CLP) poses a significant threat to human health and ecological systems. In the present study, efficient removal of CLP was achieved by thermo activated persulfate, among which sulfate radical was identified as the predominant oxidizing species responsible for the decontamination. Based on high resolution LC-MS, derivatization method and density functional theory (DFT) computation, the detailed oxidation pathways and mechanisms were proposed. The primary oxidation pathways included dechlorination-hydroxylation, decarboxylation and the formation of quinone-like moieties. Afterwards, numerous intermediate byproducts ranging from high molecular to very small ones were identified, suggesting the pyridine ring was damaged during the thermo activated persulfate process. The detected products containing six and five carbons indicated the pyridine ring cleavage would take place on the quinone-structure intermediate. Further oxidation could continue by breaking each bond on the ring-cleavage product, yielding a series of short-chain carbonyl chemicals, carboxylic acids and inorganic ions. In addition, the presence of dissolved oxygen (DO) was favorable to CLP degradation, indicating DO played an important role in applying such technology. The degradation rate constants of CLP increased appreciably with increasing temperature, and acidic pH facilitated the CLP degradation. The results obtained in this work would increase our understanding on the environmental fates of nitrogen heterocyclic compounds during sulfate radical (SO4 center dot-)-based advanced oxidation processes (SR-AOPs). (C) 2019 Elsevier Ltd. All rights reserved.