Shi YanLin, He Jiangang, Yang Xiaoyu, Zhou Wanqiang, Wang Jingyi, Li Xiaolong, Liu ChunLi
Beijing National Laboratory for Molecular Sciences, Fundamental Science Laboratory on Radiochemistry & Radiation Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Radiochemistry Lab, School of Nuclear Science and Technology, Lanzhou University, 730000, Lanzhou, China.
J Environ Radioact. 2019 Jul;203:163-171. doi: 10.1016/j.jenvrad.2019.03.011. Epub 2019 Mar 25.
This research studied the sorption behavior of uranium(VI) onto two different kinds of soils: surface soil and undersurface soil that taken from the depth of 30 m undersurface. The soil samples were collected from a low and medium-level radioactive waste disposal site in the southwest of China. The effects of pH, solid-liquid ratio and contact time on the adsorption behavior were studied by batch adsorption method. The experiment results show that the mineral composition of soil and the speciation of U in natural groundwater are two main influencing factors. Muscovite and clinochlore, two of the main minerals of soil samples, dominate the sorption behavior of uranium onto natural soils at weak acidic and near neutral pH range. Under neutral and weak alkaline conditions, the thermodynamic calculation results show that Ca and CO have significant influence on the species of uranium in aqueous solution. The U sorption reduced sharply due to the formation of the CaUO(CO) (aq) complex. This work provides a better insight of the sorption behavior of uranium onto natural soils, and gives an in-depth understanding about the influence of aqueous and surface speciation.
本研究考察了铀(VI)在两种不同土壤上的吸附行为：表层土壤和取自地下30米深处的底层土壤。土壤样品采自中国西南部的一个中低水平放射性废物处置场。采用批量吸附法研究了pH值、固液比和接触时间对吸附行为的影响。实验结果表明，土壤的矿物组成和天然地下水中铀的形态是两个主要影响因素。土壤样品的两种主要矿物白云母和斜绿泥石在弱酸性和近中性pH范围内主导了铀在天然土壤上的吸附行为。在中性和弱碱性条件下，热力学计算结果表明，Ca和CO对水溶液中铀的形态有显著影响。由于CaUO(CO) (aq)络合物的形成，铀的吸附急剧降低。这项工作为深入了解铀在天然土壤上的吸附行为提供了更好的视角，并对水相和表面形态的影响有了更深入的认识。
