Research On Bentonite-soil Mixture's Permeability Characteristics In Sanitary Landfil

With urban construction and economic development, the level of urbanization in China increased rapidly, MSW is sharp increasing with the annual growth rate of 8% to 10%, which the same growth of GDP. Many MSW production not only take up valuable space in human life, but also contaminated the soil, water, air and other environmental which threat people's survival, leachate will pollute the groundwater and nearby water sources, landfills emit harmful gases polluted atmospheric Environment. How to construct safe disposal of municipal solid waste has become one of the main environmental problems in the urban development process to resolve.In Japan, there is a set of comprehensive approach to dell with MSW. Municipal solid waste discarded by time-and-use classification, available resources recovery and utilization again. The municipal waste which can not be reused collected is usually incinerated to decrease its volume. The ash generated in incinerator is disposed into the controlled type waste landfill. Low permeation of compaction soil liner is used in sanitary landfill. The research focuses on making local soil available in landfill construction and in same time meeting the standards.This paper studies using Bentonite as additive of sanitary landfill local sand to enhance and improve the ability of imperviousness to replace compacted clay layer, looking for construction Sanitary Landfill impermeable layer of economical and practical material. The firstly, surveyed and studied the bottom impermeable system used in Utsunomiya City landfill. Through experiments to determine the basic characteristics of sand, and using compacted different addition rate of Bentonite-sand mixture take to penetration tests, then determined the optimum rate of addition of Bentonite, using different concentration of calcium solution and the actual landfill leachate on penetration test of the compacted Bentonite-sand mixture. The experimental results show that: compacted the sand added Bentonite composite sand greatly improve impervious performance when added 10 percent of Bentonite, compacted compaction soil can meet the requirements of sanitary landfill impermeable clay layer. Leachate and calcium solution can reduces impervious performance of compacted composite sand, but still ensure the low permeability properties. Composite sand, especially because the adsorption capacity of Bentonite, lead the leachate contaminated materials attenuation capability well. It is feasible that replacing soil line with Bentonite-sand mixture as low hydraulic conductivity of the Sanitary Landfill impermeable layer.