An analytical solution to contaminant advection and dispersion through a GCL/AL liner system  

作　　者：XIE HaiJian LOU ZhangHua CHEN YunMin JIN AiMin CHEN PeiXiong 

机构地区：[1]MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou 310058, China [2]Institute of Hydrology and Water Resources Engineering, Zhejiang University, Hangzhou 310058, China [3]Second Institute of Oceanography, Hangzhou 310012, China

出　　处：《Chinese Science Bulletin》2011年第8期811-818,共8页

基　　金：supported by the National Natural Science Foundation of China (50538080 and 40839902);Projects of International Cooperation and Exchanges of National Natural Science Foundation of China (5101008);China National Funds for Distinguished Young Scientists (50425825);the National Science Foundation for Post-Doctoral Scientists of China (20090451472);the National Natural Science Foundation of China (51008274)

摘　　要：An one-dimensional model for contaminant advection and dispersion through a GCL/AL liner system was developed to analyze the equivalence between a GCL(geosynthetic clay liner) and a CCL(compacted clay liner).The continuity of contaminant concentration and flux at the interface between the GCL and the underlying attenuation liner(AL) are obeyed in the model,and background concentrations in the soil liner are also considered.Based on the assumption that contaminant transport through a GCL was a steady state process,an analytical solution was obtained.Increasing the leachate head from 0.3 m to 10 m results in a reduction of the breakthrough time of benzene by a factor of 2.7.The breakthrough time of benzene increases by a factor of 7.0 when the hydraulic conductivity of GCL decreases by one order of magnitude.The breakthrough curves are more sensitive to the hydraulic conductivities of the GCL and AL(attenuation layer) than to the thickness of the AL.The standard 75 cm CCL can be replaced by a combination of a GCL and a 1.0-4.0 m thickness of AL.The proposed method can be used for preliminary design of GCL composite liners,assessing the equivalence between GCL and CCL,preliminary design of a remediation method for contaminated soils,and evaluating experimental results.An one-dimensional model for contaminant advection and dispersion through a GCL/AL liner system was developed to analyze the equivalence between a GCL （geosynthetic clay liner） and a CCL （compacted clay liner）. The continuity of contaminant concentration and flux at the interface between the GCL and the underlying attenuation liner （AL） are obeyed in the model, and background concentrations in the soil liner are also considered. Based on the assumption that contaminant transport through a GCL was a steady state process, an analytical solution was obtained. Increasing the leachate head from 0.3 m to 10 m results in a reduction of the breakthrough time of benzene by a factor of 2.7. The breakthrough time of benzene increases by a factor of 7.0 when the hydraulic conductivity of GCL decreases by one order of magnitude. The breakthrough curves are more sensitive to the hydraulic conducfivities of the GCL and AL （attenuation layer） than to the thickness of the AL. The standard 75 cm CCL can be replaced by a combination of a GCL and a 1.0-4.0 m thickness of AL. The proposed method can be used for preliminary design of GCL composite liners, assessing the equivalence between GCL and CCL, preliminary design of a remediation method for contaminated soils, and evaluating experimental results.

关 键 词：污染物浓度 解析解 扩散 对流 受污染土壤 土工合成材料 铝 衬垫系统 

分 类 号：X51[环境科学与工程—环境工程] O175[理学—数学]