帷幕工程对重金属污染扩散阻滞作用数值模拟

 地下水渗流是重金属扩散的主要作用之一。基于地下水渗流规律的对流、弥散、源汇作用，在不考虑生物降解和化学反应的情况下，以帷幕工程为对象，分析其对重金属污染物的阻滞效应。应用GMS 软件建立了污染物运移过程的一维对流-弥散仿真模型和抽压水井扰动下的地下水修复模型。研究结果表明，帷幕工程对重金属污染物的扩散和运移起到了明显的阻碍作用，降低了污染物扩散半径。在污染源持续补给的状态下，365 d 的扩散距离从900 m 缩短为465 m；帷幕工程外部观测点的污染物质量浓度从2.8 mg/L 减少到1.42 mg/L，降低了50%；在抽压水井的扰动下，帷幕工程内部凝固态污染物和溶解态污染物被吸附和被稀释的反应速度得到了提升。

Numerical Simulation of Retardation Effect of Curtain Grouting Project on the Diffusion of Heavy Metal Pollution

Groundwater interstitial flow is one of the major ways for the diffusion of heavy metal pollution. Based on the law of the convection, diffusion, and source-sink effect of groundwater flow, this paper analyzes the retardation effect of the curtain grouting project on the diffusion of heavy metal pollution, without considering biological degradation and chemical reactions. A onedimensional convection-diffusion simulation model of the transport process of contaminants and groundwater restoration model under disturbance of pumping wells were established using GMS software. The results showed that the curtain grouting project had apparent retardation effect on the diffusion and transport of heavy metal pollutants, reducing the diffusion radius. With continuous supply of pollutants in 365 d, the diffusion distance was shortened from 900 m to 465 m. The mass concentration of pollutants at the external observation site of the curtain project decreased from 2.8 mg/L to 1.42 mg/L, a reduction of about 50%. Under disturbance of pumping wells, the adsorption and dilution of pollutants in solidified and dissolved forms were accelerated in the project.