基于PHT3D的地下水中六价铀吸附反应运移数值模拟

Reactive Transport Modeling using PHT3D-A Case Study of Surface Complexation Modeling of Uranium(Ⅵ)

在铀尾矿地区溶解态U(Ⅵ)渗漏到含水层中对周围环境造成严重的威胁。本研究利用反应运移软件PHT3D对U(Ⅵ)吸附实验进行模拟,并与传统Kd吸附经验模型进行对比。模拟结果表明:传统Kd吸附经验模型在地球化学条件发生变化时无法刻画表面吸附的动态变化;由表面络合模型计算的Kd值在时空是不断变化的,其更接近实际中多变水化学条件下的吸附;应用PHT3D进行反应模拟能够在复杂地下水流条件中获得较好的效果。

In uranium tailings area, the adsorption of hexavalent uranium on its migration would heavily threaten the environ-ment and human health. In this study, a numerical example was demonstrated using the reactive transport model PHT3D based on surface complexation to simulate the uranium （Ⅵ） adsorption and migration. The reactive transport simulation results are com-pared to those using traditional constant Kd adsorption model. This study shows that Kd computed with PHT3D are varied with time and space while the geochemistry condition changed. The surface complexation model（ SCM） used in the PHT3D reactive transport simulation could be more accurate in complex flow field than constant Kd adsorption model used in MT3DMS.