Abstract A triple-layer composite liner consisting of a geomembrane liner (GMB), a geosynthetic clay liner (GCL) and a compacted clay liner (CCL) is commonly used at the landfill bottom liner system to isolate the contaminated leachates. In this paper, one-dimensional quasi-steady-state small deformation model (SDSS) was developed to investigate the behavior of organic chemicals transport in landfill composite liner system considering coupled effect of consolidation, diffusion and degradation. The first and second type bottom boundary conditions are used to derive the analytical solutions. The generalized integral transform technique (GITT) is adopted to derive the analytical solutions. The effect of consolidation on the performance of GMB/GCL/CCL with intact or leaking GMB is investigated. The triple liner under double drainage boundary condition (DDBC) has better performance compared to the case under single drainage boundary condition (SDBC). This is because the velocity induced by consolidation under DDBC is lower than that under SDBC. The effect of GCL consolidation shows an opposite trend compared to CCL consolidation. Considering GCL consolidation can increase the breakthrough time. The effective diffusion coefficient of GCL can be two magnitude orders smaller after consolidation, which provides a better diffusion barrier for the chemical transport. The effects of adsorption and degradation have been analyzed as well. Increasing the adsorption capacity of a deforming composite liner can increase the steady-state bottom flux, which shows the opposite tendency compared to the case without considering consolidation. This is due to the fact that for the case of a deforming composite liner, the advection induced by consolidation includes a new term due to the solid velocity. This velocity will result in the increase the mass of chemical migration through the composite liner.

中文翻译：

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三重填埋场内有机污染物迁移耦合固结与扩散的分析模型

摘要 由土工膜衬里（GMB）、土工合成粘土衬里（GCL）和压实粘土衬里（CCL）组成的三层复合衬里是垃圾填埋场底部衬里系统中常用的隔离污染渗滤液的方法。在本文中，一维准稳态小变形模型（SDSS）被开发用于研究考虑固结、扩散和降解耦合效应的垃圾填埋场复合衬垫系统中有机化学品的运输行为。第一类和第二类底部边界条件用于导出解析解。采用广义积分变换技术（GITT）推导出解析解。研究了固结对具有完整或泄漏 GMB 的 GMB/GCL/CCL 性能的影响。与单排水边界条件（SDBC）下的情况相比，双排水边界条件（DDBC）下的三重衬管具有更好的性能。这是因为在 DDBC 下由固结引起的速度低于在 SDBC 下的速度。与 CCL 整合相比，GCL 整合的效果显示出相反的趋势。考虑到协鑫整合可以增加突破时间。固结后GCL的有效扩散系数可以小两个数量级，这为化学输运提供了更好的扩散屏障。还分析了吸附和降解的影响。增加变形复合衬里的吸附容量可以增加稳态底部通量，与不考虑固结的情况相比，这显示出相反的趋势。这是因为对于变形复合衬管的情况，固结引起的平流包括一个新的固体速度项。该速度将导致通过复合衬垫的化学迁移质量增加。