The Role and Advantages of Geomembrane in The Closure of Landfills
1. Reduce the infiltration of rainwater and other external water into the garbage dump to reduce the landfill leachate.
2. Control odor emissions from the landfill, and release and collect combustible gas from the upper system of the landfill to achieve the purpose of controlling pollution and comprehensive utilization.
3. Inhibit the spread and spread of pathogens and their mosquitoes.
4. Prevent surface runoff from being contaminated, and avoid the spread of garbage and its direct contact with humans and animals.
5. Prevent soil erosion.
6. Promote the stability of the dump as soon as possible, provide a surface that can beautify the landscape, provide soil for vegetation growth, and facilitate the reuse of the landfill.
The closure of the landfill should follow the following points: The structure of the closed system should be divided into the waste gas layer from the surface of the garbage pile to the top surface, the anti-seepage layer, the drainage layer, and the vegetation layer.
The layer of the closed system should be selected from the following types, the exhaust layer: the closed system of the landfill should be provided with an exhaust layer so that the air pressure of the permeable layer is not greater than 0.75kPa, and the exhaust layer should be coarse For granular porous materials, the permeability coefficient is required to be greater than 1 × 10-2 cm / s and the thickness is not less than 30 cm. The exhaust layer can also use a composite drainage network with equivalent drainage performance.
Anti-seepage layer: The composite high quality textured geomembrane layer of geomembrane and geotextile should be used to construct the anti-seepage layer. The geomembrane should use high-density polyethylene (HDPE) with a thickness greater than 0.75mm, and the permeability coefficient should be less than 1 × 10-17cm/s, Geotextile should be placed on the upper and lower surfaces of the low cost textured geomembrane.