Volatility and leachability of heavy metals and radionuclides in thermally treated HEPA filter media generated from nuclear facilities.
Volatility and leachability of heavy metals and radionuclides in thermally treated HEPA filter media generated from nuclear facilities.
复制标题
核设施产生的经过热处理的 HEPA 过滤介质中重金属和放射性核素的挥发性和浸出性。
DOI：
10.1016/j.jhazmat.2012.03.081
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发表时间：
2012
影响因子：
13.6
通讯作者：
Kune
中科院分区：
文献类型：
--
作者：
I. Yoon;W. Choi;Suk;B. Min;H. Yang;Kune
本研究的目的是采用热处理来减少HEPA过滤介质的体积，并研究热处理过程中重金属和放射性核素的挥发性和浸出性。将HEPA滤料在900℃热处理2小时后转变为玻璃状块状材料。HEPA滤料中重金属含量最高的是锌，其次是锶、铅和铬，主要放射性核素是Cs-137。挥发性测试表明，在热处理过程中，放射性HEPA滤料中的重金属和放射性核素没有挥发。PCT测试表明，与其他玻璃相比，重金属和放射性核素的可溶出性相对较低。X射线衍射结果表明，锌和铯与HEPA滤料反应生成晶态硅锌矿(ZnO·SiO_2)和闪锌矿(Cs2OAl2O34SiO_2)，它们既不挥发也不易溶出。与传统的玻璃化工艺相比，将放射性HEPA滤料的体积缩小并转化为玻璃化块状材料是一种简单而节能的工艺，不需要添加剂，而且可以在相对较低的温度下进行。
The purpose of the present study was to apply thermal treatments to reduce the volume of HEPA filter media and to investigate the volatility and leachability of heavy metals and radionuclides during thermal treatment. HEPA filter media were transformed to glassy bulk material by thermal treatment at 900°C for 2h. The most abundant heavy metal in the HEPA filter media was Zn, followed by Sr, Pb and Cr, and the main radionuclide was Cs-137. The volatility tests showed that the heavy metals and radionuclides in radioactive HEPA filter media were not volatilized during the thermal treatment. PCT tests indicated that the leachability of heavy metals and radionuclides was relatively low compared to those of other glasses. XRD results showed that Zn and Cs reacted with HEPA filter media and were transformed into crystalline willemite (ZnO·SiO2) and pollucite (Cs2OAl2O34SiO2), which are not volatile or leachable. The proposed technique for the volume reduction and transformation of radioactive HEPA filter media into glassy bulk material is a simple and energy efficient procedure without additives that can be performed at relatively low temperature compared with conventional vitrification process.