饱和黄土中3H和Br-迁移的延迟特征

饱和黄土核素迁移实验表明 ,Br-的迁移速度比3 H快 ,这种现象对核素的迁移研究具有重要意义 ,但常用的模拟方法显然无法模拟出这种现象 .利用实验参数并以水流流速为已知参数 ,对实验数据进行了流速反推模拟 ,结果显示 ,3 H和Br-在饱和黄土的迁移中均存在延迟现象 ,且3 H的延迟大于Br-,模拟获得3 H的延迟因子为 1 95～ 2 0 5 ,Br-为 1 6 0～ 1 90 .对常用模拟法和流速反推法计算结果进行了比较 ,结果显示 ,采用常用模拟法获得的水流流速存在较大误差 .延迟因子的灵敏度分析结果显示 ,延迟因子对3 H和Br-在饱和黄土中的迁移具有较大影响

Retardation characters of 3H and Br- migration in saturated loess

Tests of radionuclide migration in saturated loess soil showed that Br~- migrated faster than ()~3H, this phenomenon has significant implications in the study of radionuclide migration, but has not been determined by numerical models. In this paper we proposed a new method to determine the breakthrough curves of ()~3H and Br~- by obtaining the flow velocity from the tests. The results showed that the migration of both ()~3H and Br~- are retarded in saturated loess, and retardation factors of ()~3H range from 1.95 to 2.05, and Br~- from 1.60 to 1.90, respectively. Comparison of the common method and the proposed method showed that the former gives a larger error for the identification of groundwater velocity. In addition, sensitivity analysis of retardation factor indicated that retardation factor has important influence on ()~3H and Br~- migration in saturated loess soil.