Tellurium Distribution and Speciation in Contaminated Soils from Abandoned Mine Tailings: Comparison with Selenium.
Tellurium Distribution and Speciation in Contaminated Soils from Abandoned Mine Tailings: Comparison with Selenium.
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DOI：
10.1021/acs.est.7b00955
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发表时间：
2017-05
影响因子：
11.4
通讯作者：
H. Qin;Y. Takeichi;H. Nitani;Y. Terada;Y. Takahashi
中科院分区：
文献类型：
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作者：
H. Qin;Y. Takeichi;H. Nitani;Y. Terada;Y. Takahashi
采用微聚焦X射线荧光（μ-XRF）、X射线衍射（μ-XRD）和X射线吸收精细结构（μ-XAFS）技术相结合的方法，研究了污染土壤中碲（Te）的分布和化学形态。结果表明，在废弃尾矿污染土壤中，Te以Te（VI）和Te（IV）的混合形态存在，Se以Se（IV）的形态为主。在污染土壤中，Fe（III）的氢氧化物是Se（IV），Te（IV）和Te（VI）的宿主相，但Te（IV）也可以保留伊利石。Se和Te在土壤中的形态和溶解度的差异可能是由于Se和Te与Fe（III）氢氧化物表面络合物的结构不同所致。此外，我们的研究结果表明，保留的Te（IV）在土壤中可能相对较弱，比Te（VI）由于结构纳入Te（VI）到Fe（III）的氢氧化物。这些发现对于更好地了解Te在地表环境中的溶解性、流动性和生物有效性具有地球化学和环境意义。据我们所知，这是第一个研究报告的形态和主体相的Te在田间土壤中的μ-XRF-XRD-XAFS技术。
The distribution and chemical species of tellurium (Te) in contaminated soil were determined by a combination of microfocused X-ray fluorescence (μ-XRF), X-ray diffraction (μ-XRD), and X-ray absorption fine structure (μ-XAFS) techniques. Results showed that Te was present as a mixture of Te(VI) and Te(IV) species, while selenium (Se) was predominantly present in the form of Se(IV) in the soil contaminated by abandoned mine tailings. In the contaminated soil, Fe(III) hydroxides were the host phases for Se(IV), Te(IV), and Te(VI), but Te(IV) could be also retained by illite. The difference in speciation and solubility of Se and Te in soil can result from different structures of surface complexes for Se and Te onto Fe(III) hydroxides. Furthermore, our results suggest that the retention of Te(IV) in soil could be relatively weaker than that of Te(VI) due to structural incorporation of Te(VI) into Fe(III) hydroxides. These findings are of geochemical and environmental significance for better understanding the solubility, mobility, and bioavailability of Te in the surface environment. To the best of our knowledge, this is the first study reporting the speciation and host phases of Te in field soil by the μ-XRF-XRD-XAFS techniques.