多孔介质中氚的滞留及对相关试验的影响

Tritium detention in porous media and impact to related hydrogeology parameters test

在进行氚在黏土矿物中的滞留试验基础上,对试验结果进行了总结,分析了滞留现象对相关水文地质、环境地质参数试验的影响。结果表明：氚在蒙脱石、高岭石、伊利石等孔隙介质中的平均分配系数分别为0.15 ml/g、0.10 ml/g、0.12ml/g;氚的绝对吸附量随氚水比活度的增加而增大,绝对吸附量的对数与相应氚水比活度的对数呈直线相关关系;氚的滞留将使野外弥散试验获得的弥散度和弥散系数减小,使得室内示踪试验获得的孔隙水流速比实际孔隙水流速减小5%-25%,使得按照^3H测龄方法获得的亚砂土等含水层中地下水年龄增大5%-20％．按照^3H-^3He测龄方法获得的地下水年龄比实际情况增大4％～18％。

On the basis of test of tritium detention in clay minerals, the test results are summarized and the impacts of tritium detention to related hydrogeological parameters test are analyzed and presented. It can be concluded that： ①the average partition coefficients of tritium between water and the clay minerals, such as montmorillonite, kaolinite and illite, are 0. 15 ml/g, 0.10 ml/g, 0.12ml/g respectively. ② the quantities of tritium adsorbed by the clay minerals come up with the tritium specific activities, and show a logarithm beeline relation each other. ③ the detention of tritium in porous media will make the dispersivity and the dispersion coefficient acquired from in-situ tritium dispersion test decrease, and will make the velocity of pore water, during laboratory tritium tracing test, come down by 5% -25% , and the age of groundwater within sand loam media will increase by 5% -20% with the 3H dating method, and 4% -18% with the 3 H/3 He dating method.