氯离子在边坡中运移特征模拟试验研究

发布时间：2019-07-09 15:32

【摘要】：土壤是一个非常复杂、开放的系统。全球经济迅猛发展,人类生产和生活水平不断提高,越来越多的物质经过各种途径进入土壤,使土壤环境遭到严重威胁和破坏。近年来采矿迹地的环境问题越来越受到人们的普遍关注,其中矿迹边坡的土壤污染己成为亟待解决的严重问题。采矿迹地边坡作为一个复杂的自然人为系统,在降雨条件下,边坡土壤中的污染物通过各种方式,导致区域性的污染。因此研究降雨条件下,采矿迹地边坡溶质运移规律对于土壤污染的预测、控制和修复具有重要意义。本研究进行了如下工作,对边坡土壤溶质的运移特征进行了进一步的探索和研究:(1)测定了土壤的基本物理性质,采用定水头法测定了土壤饱和渗透系数,采用张力计法测定土壤水分特征曲线,用V-G模型对土水特征曲线进行拟合,得到非饱和土壤渗透系数和扩散率,采用穿透曲线法测定了土壤弥散度。(2)通过室内边坡模型进行了降雨条件下氯离子(Cl-)在边坡中的运移试验,通过设置不同降雨条件、溶质投放位置、坡型来进行试验研究,对含水率和Cl-浓度进行了连续监测取样测定。(3)结合室内试验条件,建立了水分和溶质运移数学模型,并且通过Feflow软件进行了数值模拟,结合数值模拟结果,对不同影响因素对于Cl-运移规律的影响进行了分析。结果表明随降雨强度和降雨总量的增大,土壤非饱和带湿润区的范围扩大,溶质也随水的运动而被带至土壤深层,说明降雨的入渗作用对溶质迁移有一定影响。溶质投放位置和坡角的不同也会导致溶质运移受降雨的影响不同。
文内图片：

图片说明：直角坐标系中的单元体
[Abstract]:The soil is a very complex, open system. With the rapid development of the global economy and the continuous improvement of human production and living standards, more and more substances enter the soil through various ways, so that the soil environment is seriously threatened and destroyed. In recent years, the environmental problems of mining land have been paid more and more attention, and the soil pollution of the mine track slope has become a serious problem to be solved urgently. As a complex natural person, the slope of the mining area is a complex natural person. Under the condition of rainfall, the pollutants in the soil of the side slope can be polluted by various ways. Therefore, under the condition of rainfall, the law of the solute transport of the slope in the mining area is of great significance to the prediction, control and repair of soil pollution. The characteristics of soil solute transport in the slope were further explored and studied in this study. (1) The basic physical properties of soil were determined, the saturated permeability coefficient of soil was determined by using a constant-head method, and the characteristic curve of soil water was determined by means of a tensiometer. The soil water characteristic curve was fitted with the V-G model to obtain the permeability coefficient and the diffusion rate of the unsaturated soil, and the dispersion degree of the soil was determined by the penetration curve method. (2) The migration test of chloride ion (Cl-) in the side slope was carried out through the indoor side slope model, and the experiment was carried out by setting different rainfall conditions, the solute release position and the slope type, and the water content and the Cl-concentration were continuously monitored and measured. (3) The mathematical model of water and solute transport is established in combination with the indoor test conditions, and the numerical simulation is carried out by the Feflow software, and the influence of different factors on the Cl-migration rule is analyzed in combination with the numerical simulation results. The results show that with the increase of the rainfall intensity and the total rainfall, the range of the wet area of the unsaturated zone of the soil is expanded, and the solute is brought to the deep layer of the soil along with the movement of the water, indicating that the infiltration of the rainfall has a certain effect on the solute transport. The difference of the solute release position and the slope angle can also cause the solute transport to be influenced by the rainfall.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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