污染物击穿防污屏障与地下水土污染防控研究进展

鉴于防污屏障是控制固废填埋场地下水土污染的重要结构,为评价防污屏障的服役寿命,分别针对重金属和有机污染物,总结了污染物在黏土屏障和复合屏障中的一维运移解析解,包括非线性吸附条件下污染物在黏土屏障中的一维扩散解、污染物在有缺陷膜复合屏障中的一维运移解和温度场作用下污染物在黏土屏障中的耦合运移解析解等。评价了污染物击穿防污屏障长历时过程超重力离心模型试验的可靠性。对运行了17 a的安徽某填埋场进行现场调查,发现氯离子运移最大深度达9 m,钠离子和COD的运移深度在3~4 m。总结和评价了地下水土污染控制的竖向屏障技术,认为土-膨润土系竖向隔离墙技术在我国具有广阔的应用前景,并对今后的研究进行展望。

Review on penetration of barriers by contaminants and technologies for groundwater and soil contamination control

Barrier systems are the most important structures for landfills in terms of groundwater pollution control. Analytical solutions to one dimensional models of transport of heavy metals and organic contaminants in clay barriers and composite barriers were summarized in order to evaluate the service life of the barrier systems. The analytical solutions include the solution to a one dimensional model of diffusion of contaminants in clay barriers under piecewise linear adsorption conditions, the solution to a one dimensional model of transport of contaminants in composite barriers with geomembrane defects, and the solution to a coupled model of transport of pollutants in clay barriers under thermal effects. The reliability of high gravity centrifuge tests of long term transport of contaminants through barriers was assessed. Field investigation was carried out in a 17 year old landfill in Anhui Province. The results showed that the maximum migration depth of chloride ion reached 9m, and the maximum migration depth of sodium ions and COD reached 3 to 4m. The technologies of vertical barriers for control of groundwater and soil contamination were summarized and assessed. It was found that the application of soil bentonite cutoff walls in China generates prosperity, and further research areas were discussed.