包气带对铀尾矿库放射性液态流出物阻隔能力的实验研究

Experimental Research on Soil Barrier Ability of Radioactive Seepage from Uranium Tailings Dams

以湖南某铀尾矿库放射性渗滤液为研究对象,将铀酰离子作为特征污染因子,选取其周边有代表性的土层制作两组具有相同含水率的砂柱,研究包气带对铀废液的吸附和阻滞能力及铀酰离子在包气带中的迁移规律.结果表明:1)包气带对铀渗滤液具有较强的阻滞和载蓄作用,可有效延缓其污染地下水的时间;2)包气带对废液的蓄纳过程具有阶段性特征,可分为稳定吸纳和缓慢发育两个阶段,最大吸纳能力为38.20 kg/m^3;3)铀酰离子随着在砂土中迁移深度的增加,浓度逐渐降低.

The radioactive seepage sampled from a uranium tailings reservoir in Hunan is as the research object,the uranyl ion is picked as the typical pollution factor of radioactive seepage.Select the characteristic soil layer surrounding uranium tailings dams,and make two sets of sand column with the same moisture content.Laboratory simulation tests of sand column were performed to investigate the obstruction and adsorption capacity of unsaturatedzone to radioactive seepage,and master the regularity of uranyl ion transport in unsaturated zone.The results show that the unsaturated zone has a strong effect of obstruction and storage capacity to the uranium wastewater,which can effectively prolong the contaminated initiation time. The absorption with stage division,can be divided into two stabilization and slow development stage. And maximum absorptive capacity of unsaturated zone is 38.20 kg/m^3. With the increasing depth of migration in the sand,the concentration of uranyl ion decreased gradually.