A few days ago, the Shanghai Municipal Administration of Greening and City Appearance stated that this year Shanghai will strive to basically establish a full-process classification system, with 8,000 recycling outlets and 170 transfer stations. By the end of next year, the city's dry waste incineration capacity will reach 20,800 tons/day, and the wet waste resource utilization capacity will reach 7,000 tons/day, which can basically achieve "zero landfill" of primary domestic waste.

With the rapid increase in the level of urbanization in my country, the disposal of domestic garbage has become increasingly severe, and many cities are facing the dilemma of garbage siege.

How to deal with urban domestic waste is already a difficult problem for the government's urban management. Taking into account the cost of domestic waste disposal, direct landfill is still the treatment method adopted by most cities, but this requires a good job in landfills. The leachate's anti-leakage ability, otherwise the leakage of garbage leachate will cause serious environmental pollution, and once the pollution is caused, it will take decades or even hundreds of years of environmental restoration.

"At present, the problem of leakage of garbage leachate in domestic waste landfills in my country is not optimistic. A large number of disputes have arisen around the responsibility of garbage leachate leakage. Engineering judicial appraisal has become an important means to solve such problems and protect the green mountains and greenery. Water is also our responsibility." Dr. Ma Deyun of Beijing Institute of Construction Engineering Co., Ltd. said in an interview with a reporter from Science and Technology Daily.

Deyun Ma introduced that the current anti-seepage technology treatment of domestic waste landfills mainly adopts HDPE anti-seepage membrane technology. The general construction of domestic waste landfills is carried out after leakage detection, and the landfill uses HDPE membranes.

After the construction of this membrane is completed, it is easy to produce leakage points. According to related reports, after the construction, nine out of ten landfills have leakage problems, and seven out of ten of them have not conducted leakage point detection. .

"The leakage detection of domestic domestic waste landfills is generally carried out after the construction of the impermeable membrane is completed, and there are very few projects with waste detection after use, and the detection is more difficult. Landfills with waste work, If the leakage point and leakage range are accurately detected, the leakage area should be delineated first. This range has a large error. On this basis, the waste will be excavated. When the waste is cleared and transported to the bottom of the storage, the leakage will be carried out. The precise location of the missing point." Ma Deyun said.

The garbage removal and transportation in the above process is a very difficult and high-risk task, because the domestic garbage in the landfill will produce toxic, harmful, flammable and explosive gases, and the garbage decay has an extremely unstable structure level. During the excavation process It is extremely easy to cause engineering accidents such as landslides, deflagration and poisoning.

Therefore, the removal and transportation of landfill waste requires extremely professional construction teams and engineering experience, as well as risk prevention capabilities.

Ma Deyun said that from the perspective of engineering practice, the cause of leachate leakage mainly involves factors such as engineering survey quality, engineering design quality, engineering construction quality, the impact of the surrounding environment, engineering protection and on-site garbage operation management.

Only by comprehensively considering all relevant factors affecting leakage can the appraisal result be accurate, convincing and credible, and can reflect the authority and rigor of judicial appraisal.

For the identification and analysis of the above-mentioned problems, Ma Deyun first needs to detect the leakage point of the HDPE impermeable membrane. The most advanced technology in the world for leakage detection of HDPE film is electric spark method, leakage method, etc. These methods were originally applied in the aerospace field and used in the detection of the homogeneity of the rocket coating film. After modification, they are gradually applied to anti-seepage. In the detection of membranes, it has ultra-high detection accuracy and can accurately locate the leakage point, even the leakage point of millimeter size.

It is understood that the total investment in the construction of a domestic live waste landfill is about 150 million yuan. During the trial operation, leachate leakage was found in the flood discharge culvert and monitoring wells of the landfill area. The landfill is located in a beautiful scenic spot. In the valley, leachate leakage has affected the groundwater downstream of the valley.

This issue has attracted great attention from the local government and the Central Environmental Protection Inspection Team. After many expert demonstration meetings were held to no avail, we began to select high-level judicial appraisal agencies in China, and finally the Beijing Institute of Civil Engineering and Construction Engineering Quality Judicial Appraisal Relying on its own technical strength and more than ten years of experience in judicial appraisal, the center won the bid for the judicial appraisal project of the cause of leakage in the domestic waste landfill.

Ma Deyun and his teammates Zhang Mi, Liu Yunlong, Hao Mengyao, He He, Liu Yuejun, Ma Qiang and others, from leakage location detection, hydrogeological survey, flood discharge pipe inspection, design analysis, construction analysis, operation analysis, leakage in the reservoir area Comprehensive analysis of the reasons and other aspects started work, which also undertook the dumping of tens of thousands of cubic meters of garbage.

How to transport garbage, and how to protect the existing impermeable membrane in the transport project? The impermeable membrane should not be damaged by mechanical excavation and transport of garbage. This is a new subject, and it is the first case in the field of detection and identification.

“As a testing and appraisal unit, we must first solve the problem of garbage disposal in order to effectively improve the detection accuracy and accurately find the garbage leakage point. At the same time, due to the construction quality during the construction of the garbage dump, whether the constructed parts can carry and store the garbage, and Whether the reversed vehicle can operate in its operation is an unproven new subject and must be properly resolved. We face these problems, no one in the country can give the answer, so we can only research and solve it by ourselves. Through accurate calculation and analysis, we have given the answer. Reasonable and feasible plan." Ma Deyun said.

Experts in the industry said that this inspection and appraisal involved many problems and great difficulty in appraisal. It has realized the general contracting mode of engineering excavation and forensic appraisal, which is the first case in China. This technical service mode quickly and effectively solves the problem that the landfill cannot accurately determine the leakage point and the cause of the leakage. It has a strong demonstration effect for the identification of the cause of leakage and the environmental damage assessment of the domestic landfill. .

Shandong Jianbiao Technical Testing and Testing Co., Ltd. (JBJC for short) is a testing and testing organization with CMA testing qualification approved by the State Bureau of Quality and Technical Supervision and established in accordance with the law. In order to ensure the ecological safety of environmental protection projects, Shandong Jianbiao Technology Test and Inspection Co., Ltd. was established in August 2016. The company is engaged in the detection of environmental protection related materials such as building waterproof materials, geosynthetics, and leakage detection of anti-seepage engineering anti-seepage systems. With the large-scale application of anti-seepage materials and building waterproof materials in related projects, the safety of project leakage directly affects the safety and quality of the project. Leakage detection can objectively, fairly, scientifically and effectively supervise the project quality to truly ensure anti-seepage The quality and safety of the project.