文献类型：期刊文献

英文题名：Retention mechanisms and microstructure of Eu(III) on manganese dioxide studied by batch and high resolution EXAFS technique

作者：Sheng, G. D.[2,3];Yang, S. T.[3];Li, Y. M.[2];Gao, X.[4];Huang, Y. Y.[4];Hu, J.[3];Wang, X. K.[1,3]

机构：[1]Soochow Univ, Sch Radiol & Interdisciplinary Sci, Suzhou 215123, Peoples R China;[2]Shaoxing Univ, Sch Chem & Chem Engn, Shaoxing 312000, Zhejiang, Peoples R China;[3]Chinese Acad Sci, Inst Plasma Phys, Key Lab Novel Thin Film Solar Cells, Hefei 230031, Peoples R China;[4]Chinese Acad Sci, Shanghai Inst Appl Phys, SSRF, Shanghai 201204, Peoples R China

年份：2014

卷号：102

期号：1-2

起止页码：155

外文期刊名：RADIOCHIMICA ACTA

收录：SCI-EXPANDED(收录号：WOS:000331141200017)、、Scopus(收录号：2-s2.0-84897795875)、WOS

基金：G. Sheng and S. Yang contributed equally to this paper. Financial supports from NSFC (21207092, 11175244, 21107115, 21225730), 973 projects (2011CB933700), special foundation for high-level waste disposal of China (2007-840), and Hefei Center for physical science and technology (2012FXZY005) are acknowledged.

语种：英文

外文关键词：Eu(III); Sorption; beta-MnO2; High resolution EXAFS technique; Bent crystal analyzer

外文摘要：The batch experiment and high resolution EXAFS technique with bent crystal analyzer were combined to study Eu(III) retention mechanisms on beta-MnO2 as a function of various environmental factors. The results indicated that the sorption of Eu(III) onto beta-MnO2 was obviously dependent on pH but independent of ionic strength, suggesting the formation of inner-sphere surface complexes. Results of high resolution EXAFS analysis showed that Eu was surrounded by 8 +/- 1 O atoms in the first shell at REu-O approximate to 2.40 angstrom for all sorption samples. A second shell of Mn atoms at REu-Mn approximate to 3.78 angstrom was observed for all sorption samples, which was associated with the formation of a bidendate inner-sphere complex with chemical bonding via edge sharing to MnO6-octahedron. This study shows the utility of high resolution EXAFS technique with bent crystal analyzer to discriminate the fluorescence peak of Eu(III) from that of manganese hydroxides, whose fluorescence peaks are too close in energy to be discriminated by the conventional EXAFS technique with a low resolving solid-state detector. Both the macroscopic interaction data and the molecular level evidence of Eu(III) surface speciation at the oxide-water interface should be factored into better evaluation of Eu(III) and related radionuclide mobility in the natural environment.