Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China.
Sci Total Environ. 2019 Feb 10;650(Pt 1):479-492. doi: 10.1016/j.scitotenv.2018.08.413. Epub 2018 Aug 31.
Analytical solution for transport of organic contaminants through composite liner consisting of a geomembrane (GM), a geosynthetic clay liner (GCL), and a soil liner (SL) with finite thickness is presented. The transient diffusion-advection processes in the whole composite liner and adsorption in GCL and SL can be described by the present method. The method is successfully verified against analytical solution to a coupling transient diffusion-advection problem in double-layer porous media. The rationality of the steady-state transport assumption in GM and GCL and the semi-infinite bottom boundary assumption, which are widely adopted in the existing works, is comprehensively investigated. The overestimated zone, underestimated zone and no difference zone caused by the two assumptions under various conditions are identified. With the increase of elapsed time, the overestimated zone disappears, and the underestimated zone becomes smaller and smaller and finally is overwhelmed by the no difference zone. Moreover, the equivalency between GM/GCL/SL and GM/CCL composite liners is also properly assessed by the present method. GM/GCL/SL composite liner performs better than GM/CCL composite liner under high leachate level condition.
提出了一种由土工膜（GM）、土工合成膨润土垫（GCL）和具有有限厚度的土壤衬垫（SL）组成的复合衬垫中有机污染物传输的解析解。该方法可以描述整个复合衬垫中的瞬态扩散-对流过程以及 GCL 和 SL 中的吸附作用。该方法成功地通过双层多孔介质中耦合瞬态扩散-对流问题的解析解进行了验证。综合研究了 GM 和 GCL 中的稳态传输假设以及在现有工作中广泛采用的半无限底部边界假设的合理性。确定了在各种条件下这两个假设引起的高估区、低估区和无差异区。随着时间的推移，高估区消失，低估区越来越小，最终被无差异区所覆盖。此外，还通过该方法适当评估了 GM/GCL/SL 和 GM/CCL 复合衬垫之间的等效性。在高浸出液水平条件下，GM/GCL/SL 复合衬垫的性能优于 GM/CCL 复合衬垫。
