Technetium Speciation in Cement Waste Forms Determined by X-ray Absorption Fine Structure Spectroscopy
Technetium Speciation in Cement Waste Forms Determined by X-ray Absorption Fine Structure Spectroscopy
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X 射线吸收精细结构光谱法测定水泥废料中锝的形态
DOI：
10.1524/ract.1997.76.12.77
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
M. Denecke
中科院分区：
文献类型：
--
作者：
P. G. Allen;G. Siemering;D. Shuh;J. Bucher;N. Edelstein;C. Langton;S. Clark;Tobias Reich;M. Denecke
用x射线吸收精细结构（XAFS）光谱研究了水泥废渣中锝的化学性质。利用Tc - k边x射线吸收近边结构（XANES）作为探测锝形态的探针，我们的结果表明，在水泥添加剂——高炉炉渣（BFS）的存在下，高锝酸盐离子Tc04-发生了部分还原。还原剂FeS、Na2S和NaH2P02的加入对Tc04-的还原作用更大，而化合物FeO、Fe304和Mn304的还原作用不明显。BFS、Na2S和FeS处理水泥的扩展x射线吸收精细结构（EXAFS）数据表明，存在具有第一壳层S配位的Tc团簇。对于Na2S和FeS添加剂，在EXAFS中检测到Te-Te相互作用，显示出与tcs2相似的扩展结构。NaH2P02处理水泥的EXAFS光谱显示Te-O和Te-Te相互作用与tc02结构相似。
The chemistry of technetium in cement waste forms has been studied with x-ray absorption fine structure (XAFS) spectroscopy. Using the Tc K-edge x-ray absorption near-edge structure (XANES) as a probe of the technetium speciation, our results show that partial reduction of the pertechnetate ion, Tc04-, takes place in the presence of the cement additive, blast furnace slag (BFS). The addition of the reducing agents FeS, Na2S, and NaH2P02 produces more extensive reduction of Tc04-, while the compounds FeO, Fe304, and Mn304 are observed to be unreactive. The extended x-ray absorption fine structure (EXAFS) data for the BFS, Na2S, and FeS treated cements indicate the presence of Tc clusters possessing first shell S coordination. For the Na2S and FeS additives, Te-Te interactions are detected in the EXAFS demonstrating an extended structure similar to that ofTcS2. The EXAFS spectrum of the NaH2P02 treated cement reveals Te-O and Te-Te interactions that resemble those found in the structure ofTc02.