Se在一维风沙土土柱中的运移规律研究

Solute Transport Laws of Se in Sand Column of 1D

在室内条件下,采用垂直土柱易混置换法,就同一坡面不同坡位及不同深度的风沙土对SeO23在土壤中的运移规律的影响进行了研究。结果表明,土壤空隙度较大的坡中对应的运移阻滞因子R较小;土壤溶质运移的溶液流速为表层土壤>深层土壤,当v的变异系数大于14.1421时,R随流速增大而减小。

Based on a case study of a slope in the wind-water erosion crisscross region on the loess plateau, the influence of slope positions and depth of soil on the transport of SeO3^2- in aeolian sandy soil under the laboratorial conditions are studied using miscible displacement technique. The results indicate that retardation factor （R） is smaller in the middle of slope with bigger soil porosity and is bigger when soil porosity is smaller, so, the soil porosity is an important factor influencing the transport of SeO3^2- in aeolian sandy soil. The decreasing tendencies of R with the increase of the depth in a soil profile obviously vary with different slope positions, the order of the variability along the slope is as follows： the middle 〉 the top〉 the bottom. And the variability of R in deeper soil is smaller due to the less impact of outside environment. The flow velocity of SeO3^2- solution in surface soil is faster than in deep soil, and R decreases with the increasing of flow velocity when variance coefficient of flow velocity is bigger than 14.142 1 on the premise of similar mechanical composition, indicating that the flow velocity is also an important factor influencing the transport of SeO3^2- in aeolian sandy soil.