Arsenic release and speciation during the oxidative dissolution of arsenopyrite by O2 in the absence and presence of EDTA
Arsenic release and speciation during the oxidative dissolution of arsenopyrite by O2 in the absence and presence of EDTA
复制标题
在 EDTA 不存在和存在的情况下，O-2 氧化溶解毒砂过程中砷的释放和形态形成
DOI：
10.1016/j.jhazmat.2017.12.038
复制
发表时间：
2018
影响因子：
13.6
通讯作者：
Jia Yongfeng
中科院分区：
文献类型：
--
作者：
Wang Shaofeng;Jiao BeiBei;Zhang Mingmei;Zhang Guoqing;Wang Xin;Jia Yongfeng
The oxidative decomposition of arsenopyrite is an important source of As in surface environment. This study investigated the oxidative dissolution of arsenopyrite by O2and aqueous arsenic transformation at different pHs, dissolved oxygen (DO) contents, and temperatures in the absence and presence of EDTA. The oxidative dissolution was greatly inhibited at neutral and alkaline pH in the absence of EDTA. However, in the presence of EDTA, the oxidative dissolution rate increased linearly from pH 4 to 7. The highest dissolution rate was 3–4 times higher than that at pH 4 and 1–2 orders of magnitude higher than that at pH 7 in the absence of EDTA. This is possibly due to the lack of Fe oxyhydroxides on the surface of arsenopyrite. In the pH range of 7–10, the oxidative dissolution rate decreased linearly, possibly due to the formation of goethite and/or hematite coating. The oxidation of released arsenite (AsIII) to arsenate (AsV) took place simultaneously during the oxidative dissolution of arsenopyrite in the presence of dissolved Fe without EDTA, while no obvious aqueous AsIIIoxidation was observed in the presence of EDTA, indicating that aqueous Fe species play an important role in AsIIIoxidation.
