中文摘要：

在铀尾矿地区,溶解态U（Ⅵ）渗漏到含水层中会对周围环境造成严重的威胁.使用反应运移软件PHT3D对U（Ⅵ）在含水层中的迁移和吸附过程进行模拟.结果表明,相比于不考虑吸附情形,考虑吸附的U（Ⅵ）反应迁移阻滞现象明显.线性和Langmuir吸附等温线模型在水动力条件复杂、地球化学条件多变时的模拟效果与表面络合模型相比较差,甚至有时得到与实际相反的结果,这说明了传统Kd吸附经验模型的局限性.由表面络合模型计算得出的分配系数Kd值是时空变化的,其更能反映实际中多变水化学条件下的吸附过程,适合描述复杂的不同水文地球化学条件.

英文摘要：

The release and migration of uranium（ Ⅵ） in groundwater from uranium mill tailings have potential risk for environment and human health.Reactive transport model PHT3 D was used to simulate the U（ Ⅵ） migration and adsorption processes. Simulation results with and without adsorption showed that the retardation due to the mineral adsorption was significant. The distribution coefficient（ Kd） models including linear and Langmuir adsorption models and the surface complexation model（ SCM） were used to simulate U（ Ⅵ） adsorption. Comparison results demonstrated the limitation of traditional Kdmodel and showed that the retardation factor computed from the SCM was varied temporally and spatially. The SCM could be accurate to simulate the U（ Ⅵ） adsorption and migration in complex flow field with varied geochemical condition.