环境地球化学国家重点实验室知识库

The distribution and chemical species of tellurium (Te) in contaminated soil were determined by a combination of microfocuscd X-ray fluorescence (mu-XRF), Xray diffraction (mu-XRD), and X-ray absorption fine structure (mu XAES) 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), arid 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 Tc(VI) due to structural incorporation. of Te(VI) 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 mu-XRF-XRD-XAFS techniques.