铀、钚等在某岩土介质上的吸附及其动力学

选择甘肃嘉峪关地区细砂、强风化花岗岩、粉质粘土三种具有代表性岩土介质，通过静态批式实验获得U、²³⁹Pu、²⁴¹Am和²⁴⁴Cm在三种岩土介质上的吸附动力学过程，采用准二级动力学模型及动边界模型对实验结果进行了拟合，结果表明：U、²³⁹Pu、²⁴¹Am和²⁴⁴Cm在三种岩土介质上的吸附均符合准二级动力学模型。动边界模型拟合结果表明：U在细砂以及粉质粘土介质上的吸附主要受膜扩散控制，在强风化花岗岩介质上的吸附主要受化学反应控制；²³⁹Pu在细砂以及强风化花岗岩介质上的吸附主要受膜扩散控制，在粉质粘土上的吸附主要受化学反应控制；²⁴¹Am在三种岩土介质上的吸附主要受膜扩散控制；²⁴⁴Cm在三种岩土介质上的吸附主要受颗粒扩散控制。

Adsorption and Kinetics of Uranium,Plutonium and Other Nuclides on Geotechnical Media

Three representative media including fine sand, strongly weathered granite and silty clay in Jiayuguan area, Gansu Province were selected, and the adsorption kinetic process of U, ²³⁹Pu, ²⁴¹Am and ²⁴⁴Cm on the three media through static batch experiment were investigated. The experimental results were fitted using quasi-second-order dynamic model and the moving boundary model. The results confirm that the adsorption of U, ²³⁹Pu, ²⁴¹Am and ²⁴⁴Cm on the three media can be described by the quasi-second-order dynamic model, and the fitting results of the moving boundary model are as follows: the adsorption of U on fine sand and clay media is mainly controlled by liquid film diffusion, and on strongly weathered granite is mainly controlled by chemical reactions; the adsorption of ²³⁹Pu on fine sand and strongly weathered granite is mainly controlled by liquid film diffusion, and on clay is mainly controlled by chemical reactions; the adsorption of ²⁴¹Am on the three media is mainly controlled by liquid film diffusion; the adsorption of 244Cm on the three media is mainly controlled by intra-particle diffusion.