标题：Solid surface photochemistry of montmorillonite: mechanisms for the arsenite oxidation under UV-A irradiation作者：Yuan, Yanan; Wang, Yajie; Ding, Wei; Li, Jinjun; Wu, Feng
来源出版物：ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 卷：23 期：2页：1035-1043 DOI：10.1007/s11356-015-5017-2 出版年：JAN 2016
摘要：Transformation of inorganic arsenic species has drawn great concern in recent decades because of worldwide and speciation-dependent pollution and the hazards that they pose to the environment and to human health. As(III) photooxidation in aquatic systems has received much attention, but little is known about photochemical transformation of arsenic species on top soil. As(III) photooxidation on natural montmorillonite under UV-A radiation was investigated by using a moisture- and temperature-controlled photochemical chamber with two black-light lamps. Initial As(III) concentration, pH, layer thickness, humic acid (HA) concentration, the presence of additional iron ions, and the contribution of reactive oxygen species (ROS) were examined. The results show that pH values of the clay layers greatly influenced As(III) photooxidation on montmorillonite. As(III) photooxidation followed the Langmuir-Hinshelwood model. HA and additional iron ions greatly promoted photooxidation, but excess Fe(II) competed with As(III) for oxidation by ROS. Scavenging experiments revealed that natural montmorillonite induced the conversion of As(III) to As(V) by generating ROS (mainly HOaEuro cent and HO2 (aEuro cent)/O-2 (aEuro cent a')) and that HOaEuro cent radical was the predominant oxidant in this system. Our work demonstrates that photooxidation on the surface of natural clay minerals in top soil can be important to As(III) transformation. This allows understanding and predicting the speciation and behavior of arsenic on the soil surface.
入藏号：WOS:000368200200010
文献类型：Article
语种：English
作者关键词：Arsenite, Montmorillonite, Photooxidation, Top soil, Solid surface, Hydroxyl radical
扩展关键词：NATURAL MONTMORILLONITE; CONTAMINATED SOILS; OXALIC-ACID; HUMIC-ACID; WATER; PHOTODEGRADATION; ARSENIC(III); ADSORPTION; OXYGEN; CLAY
通讯作者地址：Li, JJ, Wuhan Univ, Sch Resources & Environm Sci, Hubei Key Lab Biomass Resource Chem & Environm Bi, Dept Environm Sci, Wuhan 430079, Peoples R China.
电子邮件地址：ljj0410@163.com; fengwu@whu.edu.cn
地址：
[Yuan, Yanan; Wang, Yajie; Ding, Wei; Li, Jinjun; Wu, Feng] Wuhan Univ, Sch Resources & Environm Sci, Hubei Key Lab Biomass Resource Chem & Environm Bi, Dept *Environm* Sci, Wuhan 430079, Peoples R China.
[Wang, Yajie] Guizhou Minzu Univ, Sch Chem & Environm Sci, Guiyang 550025, Peoples R China.
研究方向：Environmental Sciences & Ecology
ISSN：0944-1344
eISSN: 1614-7499
影响因子（2014）：2.828
