DOI: 10.1016/j.watres.2018.03.055
Scopus记录号: 2-s2.0-85047434997
论文题名: Probing the DOM-mediated photodegradation of methylmercury by using organic ligands with different molecular structures as the DOM model
作者: Zhang X. ; Li Y. ; Feng G. ; Tai C. ; Yin Y. ; Cai Y. ; Liu J.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 138 起始页码: 264
结束页码: 271
语种: 英语
英文关键词: Dissolved organic matter
; Methylmercury
; Molecular model
; Photodegradation
; Thiol
Scopus关键词: Biogeochemistry
; Biological materials
; Degradation
; Ligands
; Mercury compounds
; Molecular modeling
; Molecular structure
; Organic compounds
; Surface waters
; Chemical substituents
; Degradation products
; Dissolved organic matters
; Mercaptoethanol
; Methyl mercury
; Photodegradation rate
; Reductive process
; Thiol
; Photodegradation
; aniline
; dissolved organic matter
; dithiothreitol
; functional group
; hydroxyl group
; mercaptoethanol
; methylmercury
; thiophenol
; thiosalicylic acid
; ligand
; methylmercury derivative
; thiol derivative
; complexation
; concentration (composition)
; dissolved organic matter
; ligand
; methylmercury
; model
; photodegradation
; surface water
; thiol
; Article
; chemical structure
; complex formation
; concentration (parameters)
; first order rate constant
; limit of detection
; photochemistry
; photodegradation
; priority journal
; sparging
; chemical structure
; chemistry
; oxidation reduction reaction
; photolysis
; radiation response
; water pollutant
; Dithiothreitol
; Ligands
; Methylmercury Compounds
; Molecular Structure
; Oxidation-Reduction
; Photolysis
; Sulfhydryl Compounds
; Water Pollutants, Chemical
英文摘要: Photodegradation is the main depletion pathway for methylmercury (MeHg) in surface water. The formation of MeHg-dissolved organic matter (DOM) complexes has been found to be a key step in MeHg photodegradation. However, the major functional groups involved in the DOM-mediated process have yet to be clearly resolved. In this work, we systematically investigated the effects of DOM molecular structures on MeHg photodegradation by using a variety of organic ligands with different functional groups (e.g., thiosalicylate, thiophenol, and thioaniline). The results showed that thiol and phenyl groups may be the major functional groups governing DOM-mediated MeHg photodegradation, with photodegradation rates also dependent on the type (carboxyl, hydroxyl, and amino group) and position (ortho-, meta-, and para-) of other chemical substituents. The addition of “non-photochemically active” thiol ligands (e.g., mercaptoethanol and dithiothreitol) and high concentrations of Cl− can significantly inhibit the o-thiosalicylate-induced MeHg photodegradation, indicating that complexation of MeHg with these ligands is necessary for MeHg photodegradation. Sparging with O2 had a negligible effect on MeHg photodegradation, while sparging with N2 significantly enhanced MeHg photodegradation. This finding suggests that MeHg photodegradation may be a reductive process, which was further supported by identification of the degradation products of MeHg. A possible protonolysis mechanism of MeHg photodegradation in the presence of o-thiosalicylate was then proposed based on the findings of this study. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112772
Appears in Collections: 气候减缓与适应
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作者单位: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education and College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, 266100, China; School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, China; Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo, 454000, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Laboratory of Environmental Nanotechnology and Health Effect, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, United States
Recommended Citation:
Zhang X.,Li Y.,Feng G.,et al. Probing the DOM-mediated photodegradation of methylmercury by using organic ligands with different molecular structures as the DOM model[J]. Water Research,2018-01-01,138