Characterization of Fe(III)-saturated montmorillonite and evaluation its sorption behavior for U(VI)
Characterization of Fe(III)-saturated montmorillonite and evaluation its sorption behavior for U(VI)
复制标题
Fe(III)饱和蒙脱土的表征及其对U(VI)吸附行为的评价
DOI：
10.1515/ract-2015-2569
复制
发表时间：
2016-07
影响因子：
1.8
通讯作者：
Chen, Changlun
中科院分区：
文献类型：
--
作者：
Tan, Xiaoli;Yu, Shujun;Ren, Xuemei;Chen, Changlun
摘要放射性废物通常被密封在钢罐中，并在其周围回填一层压实的粘土，永久性地埋在深地质处置库中。不可避免地，放射性核素污染物可以从处置库释放，然后吸附到废物容器腐蚀产物或富铁矿物上。本文采用傅里叶变换红外光谱（FT-IR）、X射线粉末衍射（XRD）、扫描电镜（SEM）和比表面积（BET）等方法对Fe（III）饱和蒙脱土（Fe（III）-MMT）进行了表征，发现了Fe（III）饱和蒙脱土的表面结构和表面微孔结构的变化。通过批量实验研究了Fe（III）-MMT和钠基蒙脱土（Na-MMT）对U（VI）的吸附。较大的比表面积和阳离子交换容量以及Fe（III）（hydror）oxide相的存在对其吸附能力有很大贡献。在整个pH范围内，Fe（III）-MMT对U（VI）的吸附量均高于Na-MMT，且吸附量强烈依赖于pH和离子强度。吸附等温线可以用Langmuir和Freundlich模型较好地拟合。由吸附等温线计算的热力学参数（ΔH、ΔS和ΔG）表明，U（VI）在Fe（III）-MMT上的吸附是一个吸热的自发过程。实验结果表明，U（VI）与Fe（III）-MMT之间的相互作用对U（VI）的滞留起着重要的控制作用。这些现象需要在风险评估和反应性运输建模中加以考虑。
Abstract Radioactive waste is usually sealed in steel canisters surrounded by a layer of compacted clay back-fill, and permanent buried in a deep geological repository. Unavoidably, the radionuclide contaminants can be released from repository and then sorbed onto the waste container corrosion products or the Fe-rich minerals. Herein, we characterized the Fe(III)-saturated montmorillonite (Fe(III)-MMT) by using Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET), and found the changes of the surface incorporating Fe(III) and surface micropores. The sorption of U(VI) on Fe(III)-MMT and Na-montmorillonite (Na-MMT) was investigated by batch experiments. The larger surface area and cation exchange capacity, and the existence of Fe(III) (hydr)oxide phases in Fe(III)-MMT contributed greatly to its sorption capacity. In the whole pH range, the sorption of U(VI) on Fe(III)-MMT was higher than on Na-MMT, and the sorption was strongly depended on pH and ionic strength. The sorption isotherms were simulated well by the Langmuir and Freundlich models. The thermodynamic parameters (ΔH, ΔS and ΔG) calculated from the temperature dependent sorption isotherms indicated that the sorption of U(VI) on Fe(III)-MMT was an endothermic and spontaneous process. The observations suggest that the interactions between U(VI) and Fe(III)-MMT are important in controlling U(VI) retention. The phenomena need to be considered in risk assessment and reactive transport modeling.
登录
查看更多内容
影响因子：
6.7
作者：
Shi-peng Zhu;Hongmei Peng;Jinyao Chen;Huilin Li;Ya Cao;Yunhua Yang;Zhi-hai Feng
通讯作者：
Shi-peng Zhu;Hongmei Peng;Jinyao Chen;Huilin Li;Ya Cao;Yunhua Yang;Zhi-hai Feng
环境条件对钠蒙脱土吸附放射性核素Sr-90(II)行为的影响
影响因子：
6
作者：
Yu Shujun;Mei Huiyang;Chen Xin;Tan Xiaoli;Ahmad Bashir;Alsaedi Ahmed;Hayat Tasawar;Wang Xiangke
通讯作者：
Wang Xiangke
影响因子：
3.6
作者：
J. Prikryl;Alka Jain;David R. Turner;R. Pabalan
通讯作者：
J. Prikryl;Alka Jain;David R. Turner;R. Pabalan
影响因子：
5.6
作者：
J. Manjanna
通讯作者：
J. Manjanna
间歇法和光谱法研究钠累托石对 Ni2 的吸附
影响因子：
3.4
作者：
Tan, Xiaoli;Chen, Changlun;Wang, Xiangke
通讯作者：
Wang, Xiangke