Influence of sulfur on the mobility of arsenic and antimony during oxic-anoxic cycles: Differences and competition

CORC > 生态环境研究中心 > 中国科学院生态环境研究中心 > 环境化学与生态毒理学国家重点实验室

	Influence of sulfur on the mobility of arsenic and antimony during oxic-anoxic cycles: Differences and competition
	Ye, Li; Meng, Xiaoguang; Jing, Chuanyong
刊名	GEOCHIMICA ET COSMOCHIMICA ACTA
	2020-11-01
卷号	288 页码:51-67
关键词	Oxic-anoxic cycles Arsenic Antimony Biogenic sulfide Competition for thiolation
ISSN号	0016-7037
英文摘要	The biogeochemical cycling of arsenic (As) and antimony (Sb) is coupled with sulfur (S). Biogenic sulfide from microbial sulfate reduction under anaerobic conditions may enhance the release of coexisting As and Sb through the formation of labile thioarsenate (As v -S) and thioantimonate (Sb-v-S). To understand the competition between As and Sb for thiolation and its effect on their mobility, we investigated the speciation and fate of As and Sb in the presence of indigenous microbiota in sediments during multiple oxic-anoxic cycles. Sediments with Sb contents at low (L-Sb, 570 mg/kg Sb, 50 mg/kg As), medium (M-Sb, 2,560 mg/kg Sb, 90 mg/kg As) and high (H-Sb, 10,090 mg/kg Sb, 190 mg/kg As) levels were collected in the Xikuangshan mining area, the largest Sb mine in the world. Our aqueous speciation analysis indicated that As was released under anoxic conditions whereas Sb was mobilized during oxic cycles in all samples. The As release was not driven by the transformation of Fe-bearing phases, but by biogenic sulfide through the formation of soluble As-v-S. As-v-S was the primary soluble species under anoxic conditions as evidenced by its high percentage, up to 80% in L- and M-Sb sediments, and 60% in H-Sb sediment. As-v-S was formed prior to Sb-v-S in L- and M-Sb sediments and even suppressed Sb-v-S formation in H-Sb sediment, indicating that limited biogenic sulfide preferentially bound with As rather than Sb. The Sb mobility was not associated with sulfide, but mainly regulated by its redox transformation between mobile antimonate and immobile antimonite. X-ray absorption near edge structure (XANES) spectra of Sb, As and S showed that no As or Sb sulfide precipitation was formed during the incubation. The Fe K-edge XANES analysis suggested the minor transformation of Fe-bearing phases between goethite (32 +/- 8%), hematite (24 +/- 7%) and magnetite (25 +/- 4%), resulting in a limited effect of Fe cycling on As mobility. The results of our study signify the competition of As and Sb in thiolation and improve our understanding of the contrasting behaviors of As and Sb during oxic-anoxic cycles. (C) 2020 Elsevier Ltd. All rights reserved.
内容类型	期刊论文
源URL	[http://ir.rcees.ac.cn/handle/311016/44715]
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	Ye, Li,Meng, Xiaoguang,Jing, Chuanyong. Influence of sulfur on the mobility of arsenic and antimony during oxic-anoxic cycles: Differences and competition[J]. GEOCHIMICA ET COSMOCHIMICA ACTA,2020,288:51-67.
APA	Ye, Li,Meng, Xiaoguang,&Jing, Chuanyong.(2020).Influence of sulfur on the mobility of arsenic and antimony during oxic-anoxic cycles: Differences and competition.GEOCHIMICA ET COSMOCHIMICA ACTA,288,51-67.
MLA	Ye, Li,et al."Influence of sulfur on the mobility of arsenic and antimony during oxic-anoxic cycles: Differences and competition".GEOCHIMICA ET COSMOCHIMICA ACTA 288(2020):51-67.