岩土力学2024，Vol.45Issue(2)：417-432,16.DOI:10.16285/j.rsm.2023.0116
考虑温度变化下三层复合衬垫中重金属污染物一维运移理论模型
Theoretical model for one-dimensional transport of heavy metal contaminants in a triple-layer composite liner considering temperature change
摘要
Abstract
Aiming at the problem of one-dimensional transport of heavy metal contaminants(HMCs)in a triple-layer composite liner composed of geomembrane(GM),geosynthetic clay liner(GCL)and compacted clay liner(CCL)under the consideration of temperature change,the governing equations for thermal conduction and HMCs transport are developed based on the relevant assumptions,and a corresponding theoretical model is established.The theoretical model constructed in this study is solved numerically by the finite difference.Subsequently,a comparative analysis with the experimental measurements,the analytical solution calculations and other numerical solution calculations is performed to validly verify the reasonableness of this model.Finally,the effects of different factors on the transport laws are analyzed and discussed using Cd2+as an example.The results show that an increase in the upper temperature increases the transport flux and bottom concentration of Cd2+in the composite liner,but decreases its upper concentration.The thermal diffusion effect on the transport behaviors becomes significant with an increasing in Soret coefficient ST,and the defined breakthrough times tb are 37.9,37.2,36.4,31.2 and 26.5 a for ST of 0.001,0.005,0.01,0.05 and 0.1 K-1 in this order.The increase in the maximum adsorption capacities of GCL and CCL leads to the approximately linear growth in tb,and under a certain leachate head hb,the tb almost increases linearly with the increase of GCL thickness and CCL thickness.Furthermore,as hb increases from 0.5 m to 1.0 m,the tb reduces by an average of 8.33 a.In engineering practice,the adsorption performance and thickness of both GCL and CCL can be combined to design a composite liner,where the influence of temperature variation on barrier effectiveness should be incorporated.关键词
温度变化/热传导/重金属污染物运移/3层复合衬垫/理论模型/击穿时间Key words
temperature change/thermal conduction/heavy metal contaminants transport/triple-layer composite liner/theoretical model/breakthrough time分类
资源环境引用本文复制引用
江文豪,冯晨,李江山..考虑温度变化下三层复合衬垫中重金属污染物一维运移理论模型[J].岩土力学,2024,45(2):417-432,16.基金项目
国家重点研发计划(No.2019YFC1804002).This work was supported by the National Key Research and Development Program of China(2019YFC1804002). （No.2019YFC1804002）
