咸水在黏性土中迁移转化的试验研究

采用衡水地下水科学试验场浅层钻孔土样进行室内一维土柱渗流试验,并用地球化学模拟方法探讨黏性土对咸水迁移转化的控制机理。结果表明:黏性土对咸水迁移有一定的阻隔作用,1号土柱对Na+的阻滞作用以吸附为主,2号土柱对Na+的阻滞作用由吸附和阳离子交换共同影响;1号和2号土柱的阻盐率分别为49.8%和54.5%;1号和2号土柱中黏性土的阻滞因子R1和R2分别为1.54和3.78;咸水迁移过程中,控制水岩相互作用的主要因素是岩盐的沉淀,石膏、方解石的溶解,Mg2+、Ca2+与Na+之间的离子交换。

Experimental study on migration and transformation in cohesive soil of salt water

we took an indoor one-dimensional soil column seepage experiment based on the soil sample in the shallow layer drilling of Hengshui groundwater science test field, and tried to probe the control mechanism of cohesive soil to saltwater migration and transformation by means of geochemical simulation. The results show that the cohesive soil has some barrier effects on the salt water migration; the blocking effect of soil column No. 1 on the Na+is dominated by adsorption, while that of soil column No. 2 on the Na+is mutual influenced by adsorption and cation exchange. The salt rejection rates of soil column No. 1 and No. 2, R₁and R_2, are 49. 8% and 54. 5% respectively. The retardation factors of two soils columns are 1. 54 and 3. 78 respectively; In the process of salt water migration, the main factors to control water-rock interaction are salt precipitation, the dissolution of gypsum and calcite, and the ion-exchange among Mg²⁺, Ca²⁺and Na⁺.