Abstract Solute transport through the clay liner is a significant process in many waste landfills or unmanaged landfills. At present, researchers mainly focus on the test study about semi-membrane property of clay material, however, the influence of chemical osmosis caused by membrane effect on solute transport and fluid velocity is insufficient. In this investigation, based on the classical advection-diffusion equation, a one-dimensional solute transport model for low-permeable clay material has been proposed, in which the coupled fluid velocity related with hydraulic gradient and concentration gradient is introduced, and the semi-membrane effect is embodied in the diffusion mechanism. The influence of chemical osmosis on fluid velocity and solute transport has been analyzed using COMSOL Multiphysics software. The simulated results show that chemical osmosis has a significant retarded action on fluid velocity and pollutant transport. The proposed model can effectively reveal the change in process of coupled fluid velocity under dual gradient and solute transport, which can provide a theoretical guidance for similar fluid movement in engineering.

中文翻译：

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化学渗透对粘土中溶质运移和流体速度的影响

摘要 在许多垃圾填埋场或未管理的垃圾填埋场中，溶质通过粘土衬垫运输是一个重要的过程。目前，研究人员主要集中在粘土材料的半膜性质的试验研究上，但膜效应引起的化学渗透对溶质运移和流体流速的影响还不够。本研究在经典的对流扩散方程的基础上，提出了低渗透粘土材料的一维溶质输运模型，其中引入了与水力梯度和浓度梯度相关的耦合流体速度，半膜效应体现在扩散机制上。已经使用 COMSOL Multiphysics 软件分析了化学渗透对流体速度和溶质传输的影响。模拟结果表明，化学渗透对流体速度和污染物传输有显着的延迟作用。该模型能够有效地揭示双梯度和溶质运移作用下流体速度耦合过程的变化，可为工程中类似的流体运动提供理论指导。