Abstract Cutoff walls are widely used as in-situ vertical barriers to control pollution plumes migration in aquifer. A two-dimensional analytical model for the transport of organic contaminants through a layered subsurface system with a cutoff wall is developed. The model considers a coupled advection-dispersion-adsorption-degradation process in the whole system and a non-uniform concentration distribution of a contaminant source with respect to depth. The solution was effectively validated against a one-dimensional analytical solution and a two-dimensional numerical solution. The migration behavior of contaminants in the triple-layer system and the service performance of a cutoff wall are investigated. It is demonstrated that the previous one-dimensional contaminant migration solution would underestimate the polluted ranges but overestimate the migration distance. The consideration of a non-uniformly distributed contamination source is of great importance, especially for narrowly contaminated aquifer. The biodegradation in a cutoff wall has a significant influence on the transport of an organic contaminant through the layered system when its half-life in the cutoff wall is less than 5 years, and this effect would be enhanced when the biodegradation in natural soil is also considered. The proposed model is a practical tool for performing a comprehensive design of the location and thickness of a cutoff wall.

中文翻译：

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过渡层-截止壁-含水层系统中有机污染物迁移的二维分析模型

摘要 截流墙被广泛用作控制含水层污染羽流迁移的原位垂直屏障。开发了一个二维分析模型，用于有机污染物通过具有截断壁的分层地下系统的传输。该模型考虑了整个系统中耦合的对流-扩散-吸附-降解过程以及污染物源相对于深度的非均匀浓度分布。该解决方案针对一维解析解和二维数值解进行了有效验证。研究了污染物在三层系统中的迁移行为和隔断墙的使用性能。结果表明，先前的一维污染物迁移解决方案会低估污染范围而高估迁移距离。考虑非均匀分布的污染源非常重要，特别是对于污染较窄的含水层。当有机污染物在截流墙中的半衰期小于 5 年时，截流墙中的生物降解对有机污染物通过层状系统的传输有显着影响，当天然土壤中的生物降解作用也减弱时，这种影响会增强。经过考虑的。所提出的模型是一种实用工具，可用于对防渗墙的位置和厚度进行综合设计。尤其是对于污染较窄的含水层。当有机污染物在截流墙中的半衰期小于 5 年时，截流墙中的生物降解对有机污染物通过层状系统的传输有显着影响，当天然土壤中的生物降解作用也减弱时，这种影响会增强。经过考虑的。所提出的模型是一种实用工具，可用于对防渗墙的位置和厚度进行综合设计。尤其是对于污染较窄的含水层。当有机污染物在截流墙中的半衰期小于 5 年时，截流墙中的生物降解对有机污染物通过层状系统的传输有显着影响，当天然土壤中的生物降解作用也减弱时，这种影响会增强。经过考虑的。所提出的模型是一种实用工具，可用于对防渗墙的位置和厚度进行综合设计。