层状土中污染物的一维扩散解析解

扩散是污染物在填埋场细颗粒土质衬里中迁移的主要方式,同时土质衬里存在着成层的情形。在建立了污染物在层状土中的一维扩散模型的基础上,通过分离变量法得到了解析解。基于该解析解,编制了相应的计算程序。通过与有限差分法对比,证明了该解析解的正确性及有效性。算例分析了不同衬里的放置顺序对污染物扩散的影响,虽然两种情况下土层的浓度剖面不同,但两者的击穿曲线是一致的。该解析解可用于对试验数据的拟合、对复杂数值模型的检验以及为垃圾填埋场衬里系统的初步设计提供参考。

Analytical solution of contaminant diffusion through multi-layered soils

Diffusion is the predominant mechanism controlling contaminant transport in soil liners. An analytical solution of contaminant diffusion through layered porous media was presented. The comparisons between the results obtained by the present analytical method and the existing numerical solutions was described by figures. Furthermore, the application of the solutions was illustrated in a practical example. The present method was relatively simple to apply and could be used for preliminary design of landfill liners, evaluating experimental results, and verifying more complex numerical models.