Urban domestic waste management has become an important challenge faced by all mankind. Especially in some places in China, due to backward collection methods, lack of collection facilities, and unreasonable management and disposal methods, urban domestic waste management has formed a huge social or environmental problem. After domestic waste is landfilled, the waste internally will form a large amount of landfill gas and leachate due to bacterial action, breeding mosquitoes and mantises, and small animals such as rats and crows are rampant. After waste landfilling, in the landfill operation management, through timely covering of waste, some problems caused by exposed waste are solved. Waste covering is divided into daily covering, intermediate covering, and final covering. Generally, building materials such as clay, slag, and construction waste are selected as the covering layer. The water permeability and air permeability of these building materials are relatively prominent. Clay is the best in water and gas barrier performance among soil-type covering layer building materials. The ideal permeability coefficient of 1000mm thick compacted clay is about ten cm/s. In reality, ideal clay resources containing montmorillonite are limited, and most of what is purchased near landfills is gravel soil, sand soil, silt soil, etc. The covering requires a 300mm thick soil layer. The permeability coefficient of 300mm thick clay will be higher, and during the anaerobic degradation process of waste, clay is very easy to crack. Using artificially synthesized geosynthetic material geomembrane to replace the clay covering layer has now become this new type of application technology, with extremely fast progress rate and many advantages. Concrete geomembrane used as covering material has the following advantages: (1) It has a relatively small permeability range, and its total permeability coefficient is less than 1.0x10'cm/s. (2) It has strong environmental stress and cracking resistance, but the surface ionizing active agent in the leachate cannot damage its internal molecular structure. (3) It has the advantage of large single roll area: generally the width is 7000mm, the maximum roll length is 50-100m, and the maximum single roll production area reaches 350-700 square meters. (4) It has extremely high metal hardness, acid and alkali resistance, strong anti-aging characteristics, and long service life. (5) The installation method is simple and direct, no need for large machinery, material saving, low carbon and environmental protection, and the installation speed is extremely fast, 10,000 square meters can be laid in one day. (6) Wide product thickness range: can be between about 2.0mm-3.0mm, transported to the construction site after production from the original factory as required, and can also be constructed when necessary. (7) If black-green two-color geomembrane is used, on the one hand it is all greening, giving people a very relaxed visual. After the geomembrane layer is completely covered, the working temperature of the waste under the membrane can reach 40-50 degrees Celsius. During the day, or in places with relatively bright sunlight, because the geomembrane (black) is very easy to absorb heat, the membrane surface temperature can be as high as 80 degrees. At such a high temperature, adults and eggs on the waste surface are difficult to survive. The closed type of black geomembrane can strongly reflect ultraviolet rays entering, can almost absorb all visible light, can make general pests, mosquitoes, flies, butterfly species etc. lose their activity and reproduction ability, thereby reducing the pathogens carried and spread by them. With the use of geomembrane covering, landfill gas can be collected to the maximum extent. In the landfill, landfill waste gas will not produce disordered pollution, and the methane concentration in the air in the landfill is very low, will not reach the explosion bottom line of 5%, thereby reducing the hidden danger of fire. Using geomembrane covering can cover all waste under the membrane. White pollution (plastic bags), paper pieces, sand and dust etc. that are easily blown up by the wind in the waste are well controlled. Now in many landfills, anti-scattering nets are no longer set up. Modern sanitary landfills have also introduced concrete membrane covering process technology, using concrete membrane covering process technology to achieve reducing leachate quality through rain and sewage diversion, better recycling and use of landfill gas, thereby changing the surrounding environment of the landfill, thereby achieving harmless landfill treatment of waste. The application of concrete membrane burial process has also improved the landfill capacity of old landfills. At the same time, through this harmless treatment technology, old waste is re-preserved. After 10-15 years, mineralized waste is generated. The mineralized old waste is dug out and reused. At the same time, the terrain of the old landfill can also be used to build a new landfill. The old landfill also regains "new life". This creates a continuous landfill technology, so that the same old landfill can be continuously recycled, thereby avoiding the problem of excessive land area of old landfills.
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