[Perspective Club · Ecological Supervision] Flying ash produced by waste incineration has become a new problem. How to deal with it efficiently?

Domestic waste incineration power generation has now become a new way to solve the "siege city" of urban domestic waste. Data show that after incineration is incinerated, the volume can generally be reduced by more than 90%, and the weight is reduced by more than 80%. Among the solid waste generated, the slag accounts for about 15%and the fly ash accounts for about 5%. The reduction effect is very obvious. It is one of the most suitable methods for currently treating domestic waste.

The state also has an attitude of encouragement for domestic waste incineration projects. In 2021, the National Development and Reform Commission and the Ministry of Housing and Urban -Rural Development jointly released the "Fourteenth Five -Year Plan" urban domestic waste classification and treatment facility development plan, which proposed that by the end of 2025, the national urban domestic garbage incineration treatment capacity will reach about 800,000 tons/day. The processing capacity accounts for about 65%. With the support of the country and the efforts of various places, in recent years, the improvement of domestic waste incineration treatment capabilities has improved very obvious.

In Jiangsu Province Xinghua City's garbage incineration power plant, domestic waste incineration flyyfilled landfill disposal projects are operating. Picture source: Xinghua News Network

However, things always have two sides. Although the domestic waste incineration project has played a positive role in the reduction of garbage, the fly ash produced by incineration has become a new distress in the ecological environmental protection of some cities.

Domestic waste incineration flying ash belongs to the clear hazardous waste of the National Dangerous Waste List. Improper management and disposal will cause secondary environmental pollution and health. What needs to be noticed is that there have been problems in some places to deal with flying ash. In some places, they did not bury the ash in accordance with the state's clear requirements, but mixed with domestic waste. In some places, there are no standards for preventing measures such as dust prevention, rainproof, and anti -seepage (leakage) and other measures. Some places also illegally stacked fly ash in the name of temporary storage. These problems have brought serious hidden dangers of ecological environment.

Studies have shown that the environment and health risks of flying ash mainly come from the enriched heavy metals, dual evils and soluble salts. Although the villain is more toxic, it has a small content in the fly ash, and the water solution is extremely low, which is relatively easy to control its migration. The content of heavy metals and soluble salts is high in the fly ash, and it is easy to dissolve and release when it is easily dissolved in water, which is the top priority of environmental risk control. However, fly ash contains silicon, calcium, aluminum, magnesium, etc. as metal resources that can be used as raw materials for building materials. It can be seen that scientific disposal fly ash is not only an urgent need for ecological environmental protection and urban construction management, but also has certain economic and resource potential. However, the current waste incineration industry has a certain degree of heavy smoke and light -flying ash. It attaches importance to the construction of waste incineration projects, ignoring the capacity of supporting fly ash disposal, and only depends on the waste incineration reduction and the potential harm of fly ash. Insufficient understanding of flying ash disposal, shortcomings of disposal technology and ability are one of the current waste incineration work constraints.

In response to the problem of flying ash disposal, in August 2020, the National Development and Reform Commission, the Ministry of Housing and Construction, and the Ministry of Ecology and Environment jointly issued the "Implementation Plan for Urban Domestic Waste Classification and Treatment Facilities to Make up shortcomings", which clearly realized that the native domestic waste will be basically achieved by 2023 " Zero landfill "; the construction of garbage incineration facilities should be synchronized and clearly clearing the ash disposal. The Ministry of Ecology and Environment issued the national environmental protection standards "Technical Specifications for Domestic Waste Incineration Flying Ash Pollution Control (Trial)", further standardized and guided environmental management of domestic waste incineration flying ash. The "Fourteenth Five -Year Plan" urban domestic garbage classification and treatment facility development plan "once again emphasized that when planning and building a domestic waste incineration plant must be synchronized and clearly define the process of flying ash disposal, strengthen the front end of the coordinated disposal facilities, to avoid secondary time to the environment. Pollution.

The series of policies have been introduced to promote the steadily movement of flying ash. However, how to explore lower -cost, lower pollution, higher resource recovery rates, and fly ash disposal technology that is more in line with regional conditions is worthy of in -depth thinking and research.

At present, my country's domestic waste incineration fly ash is mainly treated by stable solidification+domestic waste landfills. This is also the main processing path adopted by most developed countries in the world. In addition to this technical path, Switzerland will be separated from the metal in the fly ash before landing; Germany's incineration fly ash is stored through abandoned rock salt mines; Japan mainly disposes high temperature melt and cement kiln to produce ecological cement or ordinary ordinary cement or ordinary. Cement, but due to the high energy consumption cost of melting methods, Japan no longer builds a new melting flying ash disposal facility. As the raw materials for flying ash as the production of building materials need to be treated, their equipment investment and operating costs are significantly higher than the traditional "stable solidification+landfill" disposal method.

In the Middle Workshop of the Hiroshima Environment Bureau, the mechanical boom in the garbage storage pool is investing the garbage into the incineration furnace source: People's Daily Online

Based on the current status of flying ash disposal, experts suggest that focus on the following aspects, and take targeted measures to promote outstanding problems.

The first is to accelerate the current environmental risk.

Due to the objective difficulty of flying ash disposal in technology, costs and venues, and insufficient understanding and importance to flying ash disposal, the problem of disconnection of waste incineration plant and fly ash disposal projects is not uncommon. Flying ash landfills and comprehensive disposal projects are the embarrassing position of "getting on the car first, then replenishing tickets", and even for a long time to become a blank city management gap, which causes the fly ash in the waste incineration plant for a long time backlog. "The phenomenon of incineration facilities. At present, the country has put forward clear requirements on this aspect. It should increase supervision and guidance, promote the implementation of relevant policies, and help all places make up the shortcomings of flying ash disposal, so that the waste incineration and fly ash disposal are promoted simultaneously.

The second is the method of flying ash for scientific decisions according to local conditions. The problem of flying ash exists in many places, but the provincial situation is different. Therefore, when choosing and flying ash disposal projects, we should adhere to the principle of seeking truth from facts and adopt measures according to local conditions. For example, the economic developed areas such as Beijing -Tianjin -Hebei, the Yangtze River Delta, and the Pearl River Delta can give priority to the comprehensive use of fly ash with high basic investment and operating costs, supplemented by safety landfills, and achieve further use of resources and reduced waste. The central and western regions of the central and western regions should adopt a handling method based on safety landfills and resource utilization as the supplemented method to avoid causing the project to be built and unavailable, and derailize with the current stage of social development. Avanic conditions with abandoned rock salt mines can carry out feasibility studies such as geological structure and environmental risks, and explore the application of flying ash deep well storage technology.

The third is to use professional forces to empower the supervision and law enforcement.

The high -treatment cost brought by the current shortcoming technology of flying ash may cause different degrees of incineration fly ash illegal dumping and illegal disposal and utilization. Therefore, ecological environment departments at all levels should seriously cope with it and effectively strengthen the supervision of the management and disposal of burning ash. It is necessary to compact the management responsibilities of the operator, do a good job of management accounts such as fly ash production, storage, utilization, and disposal, but also to strengthen supervision and business training involving enterprises involved in the ash industry. It is effective and effective, maintaining a high pressure on illegal disposal of fly ash.

(Reported by the Perspective Club Comprehensive China Environment, People's Daily, Xinghua News Network)

Edit: Cheng Yi

School pair: Wu Yueran

Review: Gong Zimo

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