Application of HDPE Geomembrane and Waterproof Blanket in Sanitary Landfill
Sanitary landfill is to lay solid waste in a thin layer of a certain thickness on the site where good anti-seepage performance liner is laid, mechanically compact it, and add soil to cover and disinfect in layers. Plenty of geosynthetics.
Sanitary landfill is to lay solid waste in a thin layer of a certain thickness on the site where good anti-seepage performance liner is laid, mechanically compact it, and add soil to cover and disinfect in layers. Plenty of geosynthetics. Then, in the field of sanitary landfill, geosynthetics are facing a huge space for development.
Bai Qingzhong, a professor at the School of Environmental Engineering of Tsinghua University, said that the sanitary landfill should be designed according to the "multiple barrier theory" of landfill pollution control.
That is to say, the landfill garbage must be pretreated to form a waste barrier, and then designed according to the principles and methods of geotechnical design to form an engineering barrier. , forming a natural geological barrier.
In addition, a qualified landfill must have sufficient landfill capacity and a long service life. The landfill capacity must reach the design amount, and the service life must be more than six years. At the same time, it is not threatened by floods, landslides, etc. The low cost of disposing of waste is also an important consideration.
Bai Qingzhong pointed out that at present, the commonly used technical methods in China include vertical water interception sheet piles, vertical water interception geological membranes, bottom sealing technology of rotary jet grouting, underground mud section, and geophysical technology applied to monitor attenuation laws. The surrounding enclosures in sanitary landfills can be reinforced by means of anti-seepage, water isolation, isolation and reverse filtration, drainage, reinforcement, etc. Prevent landfill leachate from seeping out, guide the leachate to drain away, and recharge it to prevent garbage from sliding and being covered by garbage. Anti-seepage is the main symbol of sanitary landfill treatment technology. It can prevent the leachate and landfill gas generated during the landfill process from polluting the water and soil of the landfill, reduce the amount of leachate produced, and provide for future treatment. The orderly and controlled collection and utilization of landfill gas creates space. The technical key of anti-seepage is the structure of the anti-seepage layer, and its structural form directly determines the anti-seepage effect and construction investment.
At present, the anti-seepage linings used at home and abroad mainly include high-density polyethylene geomembrane, bentonite waterproof blanket (GCL), non-woven geotextile, composite drainage net and other materials. Among them, HDPE film, as a polymer synthetic material, has good tensile properties, strong corrosion resistance, high anti-aging properties, excellent physical and chemical properties, and has a service life of more than 50 years. It has become the "main force of materials used in domestic sanitary landfills." military".
Properly deploying HDPE membrane and other geosynthetic materials according to environmental requirements and launching the most reasonable design plan has become the most correct practice recognized by the market. According to the statistics of the Ministry of Housing and Urban-Rural Development, the domestic sanitary landfill treatment market is in a period of stable development, and it will still be in a period of rising growth during the "13th Five-Year Plan" to "14th Five-Year Plan" period. demand will also increase significantly.
Despite this, there are still many problems worthy of attention in the development of domestic sanitary landfills. Liu Chang, deputy chief engineer of the Environmental Sanitation Engineering Technology Research Center of the Ministry of Housing and Urban-Rural Development, said that the state encourages PPP to develop into the capital market, but the level of entry into the capital market for landfills has always been relatively low, and the harm brought about is the threshold for sanitary design and products. A large number of local design institutes and companies have entered the industry, reducing costs, but also bringing problems such as design quality, geosynthetics quality, and construction quality. In addition, domestic sanitary landfills are also faced with the technical problems of "three highs and one low".
The so-called three highs refer to high leachate concentration, high leachate water level, and high risk of precipitation failure; one low refers to the low stability and safety factor of sanitary landfills, and the application of geosynthetics and sanitary landfills has inconsistencies in design and construction. matching phenomenon.
Based on this, Liu Chang said that in terms of future development, we should refer to the characteristics of China's sanitary landfills to develop and utilize geosynthetic materials. In addition, the development of related monitoring and quality control technologies such as landfill liner leakage detection Applications, optimization and specification of geosynthetics in Sanitary Landfill Standards and Specifications are equally urgent.