Comparison of antimony behavior with arsenic under various soil redox conditions
Comparison of antimony behavior with arsenic under various soil redox conditions
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DOI：
10.1007/bf02839926
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发表时间：
2006-03
期刊：
影响因子：
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通讯作者：
S. Mitsunobu;T. Harada;Y. Takahashi
中科院分区：
文献类型：
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作者：
S. Mitsunobu;T. Harada;Y. Takahashi
采用X射线吸收精细结构（XAFS）光谱法测定了日本爱媛县市之川矿尾矿土壤样品和实验室土壤-水体系中Sb和As的氧化态和主相。采用HPLC-ICP-MS法测定了土壤水中Sb和As的形态。在市之川的土壤水系统中，Sb在很宽的氧化还原范围内（Eh = 360 ~ −140 mV，pH 8）只以氧化态Sb（V）存在，而As则以As（III）和As（V）的混合物存在。这一发现在实验室实验中得到了证实。这些结果表明，Sb（V）是一个非常稳定的形式在环境中，Sb的氧化在更负的Eh比As。结合铁和锰XAFS分析的结果和Sb，As，和铁在土壤中的丰度之间的正相关性，Sb和As在土壤中的主机相是Fe（III）的氢氧化物。锑和砷的XAFS分析也与这一发现相一致。在还原条件下，As在土壤水的浓度增加，而Sb的下降，在Ichinokawa和实验室系统。这表明，这种对比行为主要是由Sb和As的不同氧化还原性质控制的。
The oxidation states and host phases of Sb and As in soil samples of mine tailing (Ichinokawa mine, Ehime, Japan) and in laboratory soil-water systems were determined by X-ray absorption fine structure (XAFS) spectroscopy. HPLC-ICP-MS was used for speciation of Sb and As in soil water. In the Ichinokawa soil water system, Sb was present exclusively as the oxidized form, Sb(V), over a wide redox range (from Eh = 360 to −140 mV, pH 8), while As was present as a mixture of As(III) and As(V). This finding was confirmed in the laboratory experiments. These results suggest that Sb(V) is a very stable form in the environment and that Sb is oxidized at more negative Eh than As. Combining the results of Fe and Mn XAFS analyses and a positive correlation among Sb, As, and Fe abundances in the soil, the host phases of Sb and As in soil were Fe(III) hydroxide. XAFS analyses of Sb and As are also consistent with this finding. Under reducing conditions, the concentration of As in the soil water increased whereas that of Sb decreased in both the Ichinokawa and laboratory systems. This suggests that this contrasting behavior is controlled mainly by the different redox properties of Sb and As.