无机盐溶液渗流过程中化学作用对粉砂渗透性的影响

摘要

以生活源污染质中的主要无机成分在粉砂层渗流过程中土体渗透性变化规律为研究内容.在确定NaCl、MgCl2、CaCl2、Na2CO3、CaCO3为生活源污染质主要无机成分的基础上,通过室内模拟试验装置测试和土体成分测定,得到渗流条件下5种无机盐化学作用下粉砂的渗透系数.结果表明:粉砂的渗透系数随渗流无机盐浓度的升高而降低,碳酸盐类较其他无机盐类对粉砂渗透性的影响更为显著,无机盐渗流和化学作用下粉砂渗透系数在深度上的变化情况表现为深度越大、粉砂的渗透系数越低.且经过不同盐溶液渗流土体后,土体成分发生了不同的改变.%The structure and properties of soil are gradually changed during the seepage of domestic pollutants mainly composed of domestic sewage and leachate.The variation patterns of soil permeability during the seepage of main inorganic components of domestic pollutants in silty sand layers are studied.Based on the identification of the main inorganic components in domestic pollutants as NaCl, MgCl2, CaCl2, Na2CO3and CaCO3, the permeability coefficients of silty sands under the seepage effects and chemical actions of five kinds of inorganic salt were deter-mined by means of laboratory simulation tests and the following determination of soil composition.Furthermore, the influence patterns and mechanisms of inorganic solution on the permeability of silty sand layer were analyzed and re-vealed.The results demonstrate that the components of inorganic solution have distinct effects on the permeability of silty sands.Specifically, the permeability coefficient of silty sand decreases with the increasing concentration of in-organic salt.Meanwhile, the carbonate solutes exert more significant effect on the permeability of silty sands than other inorganic salt solutes.Under such effects as solution seepage and chemical actions, the change of permeability in depth indicates decreasing permeability coefficients with the increasing depth.Moreover, the soil components are diversely changed due to the seepage of different salt solution.