Study Of Compression And Filtration Behaviors Of MSW And Hydraulic Behaviors Of Landfills

Land filling is one of the most economical and efficient ways to treat Municipal Solid Waste (MSW). To avoid the secondary pollution of landfills, usually, the Leachate Collection and Removal System (LCRS) must be installed over the barrier that is located at landfills' bottom side, to collect and remove leachate to fractionating facility. The leachate collection and removal layer must be designed to ensure that leachate can be removed rapidly and leachate head is lower than some safety limit. Therefore how to determinate the maximum saturated depth over the barrier is one of the key subject. Based on Dupuit (1971) assumption, this paper presents numeric solution for steady drainage on a sloping impervious barrier with no flow across the up-stream boundary. By comparison with the results of McEnroe(1993) and Qian(2004),the method presented in this paper is accurate and rational.The component of landfill waste is very complex, and its structure is instable, so the behavior of MSW is very complex. And till now there is no model that is widely considered rational. Moreover, its compression behavior is very important for analyses landfill's capability and benefit. This thesis also discusses the compression characteristics of MSW, and analyses the mechanical property of solid phase of MSW, specially considering the effect of the gas that trapped in solid phase content on bulk density. A theoretical model is established to simulate the experiment procedue. A series of large-scale consolidation experiments were made and the results are presented to validate the rationality of the theoretical model.In this thesis, a large-scale test unit is developed for study the behavior of the MSW filtration, under different stress level. And a fitted linear regression equation of MSW porosity and hydraulic conductivity is developed. According to the analysis of experiments result, the function relationship of hydraulic conductivity and MSW porosity is expounded.The leachate yield is another key parameter in the process of design landfills. In this thesis, based on the U.S.EPA HELP (Hydrologic Evaluation of Landfill Performance) Model a hydrologic simulation was made, according to the result of filtration experiments, for study the leachate yield. And the model is corrected. The simulation result shows that effect of stress field to hydrologic analysis should not be ignored.