Adsorption of monothioarsenate on amorphous aluminum hydroxide under anaerobic conditions
Adsorption of monothioarsenate on amorphous aluminum hydroxide under anaerobic conditions
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厌氧条件下无定形氢氧化铝对硫代砷酸盐的吸附
DOI：
10.1016/j.chemgeo.2015.04.018
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发表时间：
2015-06
期刊：
影响因子：
3.9
通讯作者：
Yongfeng Jia
中科院分区：
文献类型：
--
作者：
Fan Xiao;Shaofeng Wang;Liying Xu;Ying Wang;Zidan Yuan;Yongfeng Jia
硫代砷酸盐是某些硫化物沃茨中砷的主要存在形态，它们与矿物的相互作用在砷的地球化学循环中起着重要作用。研究了不同pH条件下，无定形氢氧化铝（am-Al（OH）3）对单硫代砷酸根（mtAsV）的吸附行为，并利用X射线吸收光谱（XAS）和傅里叶变换红外光谱（FTIR）对吸附态砷进行了表征。结果表明，在所有pH值（4-10）下，am-Al（OH）3对mtAsV溶液中砷的吸收量（86-16 mg·g-1）远小于对AsV溶液中砷的吸收量（112 ~ 50.5 mg·g-1）.在酸性条件下，MtAsV被部分还原为亚砷酸盐，同时生成单质硫，与am-Al（OH）3的相互作用增强了MtAsV的还原反应，这归因于am-Al（OH）3表面的酸催化作用.在吸附过程中，mtAsV也发生了向砷酸盐的转化。As K边X射线吸收近边结构（XANES）谱的线性组合拟合（LCF）表明，am-Al（OH）3上吸附的As主要以mtAsV的形式存在，少量以亚砷酸盐和砷酸盐的形式存在. X射线吸收精细结构（EXAFS）和红外光谱（FTIR）分析结果表明，mtAsVon am-Al（OH）3的吸附过程中存在双核配位作用.这项研究是第一个文件的mtAsV吸附铝氢氧化物，是必要的，以评估地球化学循环的砷在硫化物的自然或采矿影响的环境。
Thioarsenates have been found to be major arsenic species in some sulfidic waters and their interactions with minerals play an important role in the geochemical cycling of arsenic. This work investigated the sorption behavior of monothioarsenate (mtAsV) on amorphous aluminum hydroxide (am-Al(OH)3) at various pHs and characterized the adsorbed arsenic by using X-ray absorption spectroscopy (XAS) and Fourier transform infrared spectroscopy (FTIR). The uptake of arsenic by am-Al(OH)3from mtAsVsolution (86–16 mg·g− 1) was found to be much less than that from arsenate (AsV) solution (112–50.5 mg·g− 1) at all pHs applied (4–10). MtAsVwas partly reduced to arsenite with concurrent production of elemental sulfur, and the interaction with am-Al(OH)3at acidic pH enhanced the reduction, which is attributed to acid-catalysis at the am-Al(OH)3surface. Transformation of mtAsVto arsenate also occurred during the adsorption process. The linear combination fitting (LCF) of As K-edge X-ray absorption near edge structure (XANES) spectra indicated that the arsenic adsorbed on am-Al(OH)3was present dominantly as mtAsV, with minor amounts as arsenite and arsenate. The As K-edge extended X-ray absorption fine structure (EXAFS) and FTIR results suggested that bidentate binuclear complexation was involved in the adsorption of mtAsVon am-Al(OH)3. This study is the first documentation of mtAsVsorption on aluminum hydroxides and is necessary to assess geochemical cycling of arsenic in sulfidic natural or mining-impacted environments.
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影响因子：
7.3
作者：
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通讯作者：
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作者：
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影响因子：
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作者：
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影响因子：
5
作者：
Hollibaugh, JT;Carini, S;Wallschläger, D
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Wallschläger, D