我国四类衬垫系统防污性能的比较分析  

Comparison of the performance of four types of liner systems in China

作　　者：谢海建[1,2] 詹良通[1] 陈云敏[1] 楼章华[1,2] 

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058 [2]浙江大学水文与水资源工程研究所,浙江杭州310058

出　　处：《土木工程学报》2011年第7期133-141,共9页China Civil Engineering Journal

基　　金：国家自然科学基金资助项目(50538080;40839902和51008274);国家杰出青年科学基金项目(50425825);中国博士后基金资助项目(20090451472);浙江省自然基金项目(Y5100402)

摘　　要：对我国填埋场采用的四类衬垫进行了防污性能的比较分析。评价参数包括渗漏率、污染物击穿时间及衬垫系统底部浓度值。除了2m压实黏土衬垫(CCL)外,其余3种均为包含土工膜(GM)的复合衬垫。分析模型采用了污染物通过有缺陷膜复合衬垫的一维运移解析解。以镉离子(Cd2+)为渗滤液中重金属离子的代表;以苯为其中挥发性有机污染物的代表。研究表明土工复合膨润土垫(GCL)复合衬垫的渗漏率最小,2m黏土最大,两者的差别可在3～5个数量级。GCL复合衬垫对重金属离子具有较好的防污性能,尤其是在高水头及复合衬垫接触较差的情形。厚度较大的2m黏土对挥发性有机污染物的防污性能较好,其击穿时间要比GCL复合衬垫大2～3个数量级。随着水头的增大,CCL复合衬垫的防污性能逐渐地优于2m黏土。在10m水头作用下,CCL复合衬垫底部的100年浓度可比2m黏土小近一个量级。单层膜衬垫的防污性能较差,不适合作为填埋场的衬垫系统。控制填埋场复合衬垫的施工质量和渗滤液水头尤为重要。Four types of landfill liner systems were compared in terms of leakage rate,mass concentration,and contaminant breakthrough time.One is 2 m-thick compacted clay liner（CCL,and the other three are composite liners consisting of geomembrane and CCL or geosynthetic clay liner（GCL）.The analyses employed a one-dimensional analytical model for analyzing contaminant transport through defects in the geomembrane component of composite liners and diffusion of volatile organic compounds through intact composite liners.Cadmium and benzene were used to represent inorganic and organic leachate constituents.The composite liner with a GCL had the lowest leakage rate of the four liner systems,while the 2m-thick CCL had the largest leakage rate.GCL composite liner provides the best barrier for inorganic contaminant,especially for the case of high leachate level and poor interface contact of composite liner.The thicker CCL is the best barrier for the volatile organic contaminants.The breakthrough time of CCL for benzene is 2 to 3 orders of magnitude greater than that of GCL composite liner.The performance of the CCL composite liner is much better than the single compacted clay liner when the leachate level in the landfill is relatively high（e.g.,more than 10 m）.The 100-year concentration at the bottom of CCL composite liner is approximately 10 times lower than that of 2 m CCL.The single geomembrane liner is not suitable for landfill liner system.The construction quality of the composite liner and the leachate level in the landfill should be strictly controlled.

关 键 词：压实黏土 土工复合膨润土垫 复合衬垫 填埋场 等效性 污染物运移 

分 类 号：TU411.4[建筑科学—岩土工程]