Municipal Sludges as Landfill Barrier Material

摘要

The aim of this research is to find substitute barrier materials for natural clay from two kinds of municipal sludge: waterworks sludge (S_w) and dredging sludge (S_d). Laboratory tests were performed first to determine their Atterberg limits and hydraulic conductivity. Based on the results, recommendation of using waterworks sludge is proposed. Then, shear strength test was performed and we found the shear resistance property of waterworks sludge is strong enough to keep slope stability. In order to evaluate the possibility of secondary pollution, we further determined the heavy metal contents of waterworks sludge and the result shows that secondary pollution is less possible to happen. Finally, economic analysis proves that reusing waterworks sludge as barrier will save a great amount of money for both landfill and waterworks. At the end of this article, we offer the proposal to use waterworks sludge and suggest a further long-term simulated landfill test.