Probing the DOM-mediated photodegradation of methylmercury by using organic ligands with different molecular structures as the DOM model
文献类型：期刊论文
| 作者 | Zhang, Xiaoyan; Li, Yanbin; Feng, Gang; Tai, Chao; Yin, Yongguang; Cai, Yong; Liu, Jingfu |
| 刊名 | WATER RESEARCH
 |
| 出版日期 | 2018-07-01 |
| 卷号 | 138页码:264-271 |
| 关键词 | Methylmercury Photodegradation Dissolved organic matter Molecular model Thiol |
| ISSN号 | 0043-1354 |
| 文献子类 | Article |
| 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 O-2 had a negligible effect on MeHg photodegradation, while sparging with N-2 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. (C) 2018 Elsevier Ltd. All rights reserved. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/41019]  |
| 专题 | 生态环境研究中心_环境化学与生态毒理学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | Zhang, Xiaoyan,Li, Yanbin,Feng, Gang,et al. Probing the DOM-mediated photodegradation of methylmercury by using organic ligands with different molecular structures as the DOM model[J]. WATER RESEARCH,2018,138:264-271. |
| APA | Zhang, Xiaoyan.,Li, Yanbin.,Feng, Gang.,Tai, Chao.,Yin, Yongguang.,...&Liu, Jingfu.(2018).Probing the DOM-mediated photodegradation of methylmercury by using organic ligands with different molecular structures as the DOM model.WATER RESEARCH,138,264-271. |
| MLA | Zhang, Xiaoyan,et al."Probing the DOM-mediated photodegradation of methylmercury by using organic ligands with different molecular structures as the DOM model".WATER RESEARCH 138(2018):264-271. |
入库方式： OAI收割
来源：生态环境研究中心
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