悬浮颗粒促进下重金属污染物的渗透迁移及耦合过程求解

利用自行设计的可控制温度的污染物渗透迁移试验装置，研究悬浮颗粒对重金属离子渗透迁移的促进效应及水动力学耦合过程。建立悬浮颗粒最大沉积浓度函数的概念及其数学表达式，揭示悬浮颗粒迁移过程中诸如悬浮颗粒粒径、浓度、渗透速度、温度效应等对重金属离子迁移过程的影响机制。考虑沉积过程中的水动力学弥散效应及再释放效应，建立悬浮颗粒与重金属离子耦合迁移过程的控制方程，并基于源函数法发展一种注入浓度随时间变化的理论求解方法。利用室内土柱试验穿透过程，提出悬浮颗粒与重金属离子耦合迁移参数的确定方法。将已有一维情形下的解答推广到半无限体表面作用污染物浓度为任意区域分布和随时间任意变化的一维对流和三维弥散情形，并以轴对称边界条件为例示范性地给出污染物浓度随时间和空间的演化过程。这些研究在诸如污染物治理、地下水开采、地热资源开发和化学工业等领域有重要的应用价值。

The facilitation effect of the suspended particles on the seepage migration of heavy metal ions and the coupled hydrodynamic processes are studied using a temperature-controlled laboratory apparatus. The concept of maximum deposition concentration function is proposed and the mathematical model is also established. Using the breakthrough curves of suspended particles and heavy metal ions, many factors such as the size of suspended particles, concentration, seepage velocity and temperature are discussed and the affecting mechanism of suspended particles on the migration of heavy metal ions are studied. The coupled governing equations of suspended particles and heavy metal ions, which take into account the dispersion effect in the process of deposition kinetics and the release effect of sorbed particles, are established; furthermore the theory solution is derived by the source function method, in which the injection concentration of contaminants varies with time. A method of the coupled transport parameters between suspended particles and heavy metal ions is proposed using column penetration tests. The above one-dimensional solutions are then extended to the analytical method for the three-dimensional problem of contaminant migration, which account for the one-dimensional flow and three-dimensional dispersive effect, in a porous medium subjected to a local contaminant source with arbitrary geometry and intensity varying with time and coordinates on its free surface. As a typical example, an axial physical model is calculated, which gives the evolutions of contaminant migration with time in space. These studies can be widely used in various engineering fields such as the pollutant purification, exploration of groundwater, extraction of geothermal energy, and chemical industry, etc.