文献类型：期刊文献

英文题名：Sulfate radical mediated degradation of 5-halogenosalicylic acids: Phenoxyl radical transformation pathways

作者：Zhou, Lei[1,2,3];Zhao, Qing[1,2];Yang, Xuerui[1,2];Ferronato, Corinne[4];Chovelon, Jean-Marc[4];Sleiman, Mohamad[5];Richard, Claire[5]

机构：[1]East China Univ Sci & Technol, Shanghai Environm Protect Key Lab Environm Stand, Sch Resources & Environm Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Resources & Environm Engn, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China;[3]Shanghai Inst Pollut Control & Ecol Secur, Shanghai 200092, Peoples R China;[4]Univ Claude Bernard Lyon 1, Univ Lyon, CNRS, IRCELYON, 2 Ave Albert Einstein, F-69626 Villeurbanne, France;[5]Univ Clermont Auvergne, CNRS, Sigma Clermont, Inst Chim Clermont Ferrand, F-63178 Aubiere, France

年份：2020

卷号：394

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：;EI(收录号：20201408370003);WOS:【SCI-EXPANDED(收录号:WOS:000551901000009)】；

基金：The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China (Grant No. 21806037).

语种：英文

外文关键词：Laser flash photolysis; Aromatic ring cleavage; Halogen release; Dissolved oxygen; Mineralization

摘要：In the present study, we investigated the degradation kinetics and transformation pathways of two 5-halogen-osalicylic acids (5XSAs), namely, 5-chlorosalicylic acid (5ClSA) and 5-bromosalicylic acid (5BrSA) by sulfate radical (SO4 center dot-) in a thermo-activated persulfate system. The reaction pathways and mechanisms were proposed based on laser flash photolysis (LFP) techniques, HPLC-HRMS and molecular orbital calculations. Our results revealed that efficient removal of 5XSAs could be achieved by thermo-activated persulfate, and phenoxyl radicals were found to play key roles in the primary oxidation pathways. The subsequent transformation of phenoxyl radicals included hydroxylation and coupling processes. The resulting coupling products could undergo secondary reactions with sulfate radical, including dehalogenation, decarboxylation and hydroxylation. Hydroxylated products were in turn oxidized by SO4 center dot-, leading to the ring opening and the formation of a series of small molecular carbonyl byproducts. These processes could be responsible for the mineralization and the release of Br- or Cl-. In addition, the degradation rate constants of 5XSAs increased appreciably with increasing temperature, and higher efficiency of oxidation was observed around neutral initial pH. Moreover, degradation kinetics were found to be hardly affected by dissolved oxygen (DO), showing the possibility of applying SR-AOPs under environmental realistic conditions, not only for surface waters, but also for oxygen-deficient underground waters. The present work could increase our understanding on the reactivity and pathways of halogen phenols widely present in natural waters.