Evaluation of the Performance of Contaminant Mitigation of Chinese Standard Municipal Solid Waste Landfill Liner Systems

摘要

In this paper, the Chinese stanadrd Municipal Solid Waste (MSW)landfill liner systems are introduced. Two types of the standard liners are composed of a natural clay layer with a thickness of 2 m (herein titled CN 1 liner), and a composite liner (a geomembrane (GM) liner underlain by a compacted clay liner (CCL) with a thickness of 1 m) (herein titled CN 2 liner), respectively. The performance of these two types of liners are evaluated based on three criteria: 1) maximum landfill leachate head (y_(max)) over the liners; 2) leachate rate through liner systems; 3) peak concentration and mass of the targeted contaminant (dichloromethane, DCM) discharged in to an aquifer below the assumed landfill. To calculate y_(max), the Giroud's 1992 method is adopted. It is assumed that there a certain number of holed wrinkles in the geomembrane liner. The Rowe's 1998 analytical method is used to calculate the leachate leakage through the GM/CCL system. The results show that the value of y_(max) for Chinese standard liner systems are much higher than the limited value regulated by most European and northern American countries. The caclualted leakage rate, peak concentration and maximum mass at the aquifer for CN 1 are greater than that for CN 2, indicating that the former is less strict than the latter one.