The implementation of more than 10 years of "domestic waste incineration pollution control standards" (GB18485-2001) will be revised to replace the new standard, the operation of domestic waste incineration facilities and pollution emission control will be more stringent, and the municipal waste treatment related inputs will be forced to further increase under the new standard.
The Ministry of Environmental Protection will consider and adopt in principle the draft revised standards "domestic waste incineration pollution control standards", compared with the 2001 version of the standard, not only significantly tightened sulfur dioxide, nitrogen oxides, particulate matter and other conventional pollutants such as pollution emission pollutants and dioxins, heavy metals and other characteristic pollutants emission limits, but also increased carbon monoxide and other control indicators; at the same time, the waste into the furnace, Monitoring requirements have been revised accordingly.
Compared with GB18485-2001, GB18485-2014 is more in line with the reality of the requirements, not only more stringent, but also more scientific, especially the new condition control indicators, pollution control from the end to the process of the process, is a positive exploration of China's environmental standards development.
Pollutant emission limits have been significantly tightened
The emission concentration limits for major pollutants have basically been comparable to those of the European Union, and the dioxin category has been tightened from 1.0 ngTEQ/m3 to 0.1 ngTEQ/m?
The new emission limits for pollutants have been tightened to 0.1 ngTEQ/m?
In the new standard, the emission limits for pollutants such as particulate matter, heavy metals (mercury, cadmium thallium, lead and others), HCl, SO2, NOx and dioxins have been tightened significantly. For example, the new standard specifies that particulate matter is tightened from 80mg/Nm? to 20mg/Nm? (daily average), mercury is tightened from 0.2mg/Nm? to 0.05mg/Nm?, and dioxins are tightened from 1ngTEQ/m? to 0.1ngTEQ/m?, which is on a par with the European Union standard.
The tightening of pollutant emission limits for waste incineration is a general trend, which is not only related to the environmental situation, other industry emission standards continue to tighten, but also with the waste incineration industry itself to improve the level of technology and incineration scale.
The beginning of this century, China's waste incineration treatment facilities only 36, and the scale is small, the daily processing capacity of 6520 tons (2001 data), the emission of pollutants and industrial emissions compared to minimal. But this value has doubled several times. According to "China's urban construction statistical yearbook", in 2012, the number of China's waste incineration plant has 138, the daily incineration capacity of more than 120,000 tons, the annual incineration volume of nearly 40 million tons, compared with more than 10 years ago has increased 15 times. At the same time, incineration capacity accounted for the proportion of harmless waste disposal also increased from less than 3% in 2001 to nearly 30%, and is still increasing rapidly.
According to relevant calculations, with the increase in waste incineration, the amount of pollutants emitted also increased. To nitrogen oxides, for example, GB18485-2001 regulations (400mg/m?), in 2011, the national flue gas emissions of nitrogen oxides totaled 24,043,000 tons, domestic waste incineration of nitrogen oxides emissions between 55,000 tons to 96,000 tons, accounting for 0.23% to 0.40%. If the implementation of the new standard (daily average value of 250mg / m?), the year of domestic waste incineration of nitrogen oxides emissions can be compared to the implementation of the current standard to reduce 1/4, equivalent to the national nitrogen oxides in 2011 reduced by about 0.1%, accounting for the entire "Twelfth Five-Year Plan" nitrogen oxides emission reduction targets of about 1%.
Sulfur dioxide is roughly similar to NOx. As for dioxins, China's new large-scale waste incineration projects can already meet the EU standard of 0.1ngTEQ/m?"
The new standard stipulates that a single furnace 50 tons / day below the domestic sewage treatment facilities generated sludge and general industrial solid waste incinerator dioxin class determination of the average value of the implementation of 1.0ngTEQ/m?; scale 50 tons / day ~ 100 tons / day incinerator dioxin class determination of the average value of the implementation of 0.5ngTEQ/m?; scale is greater than or equal to the incinerator of 100 tons / day implementation of 0.1ngTEQ/m?
Compared with the domestic waste incinerator, the incinerator to deal with domestic sewage treatment facilities of sludge and general industrial solid waste incinerator furnace size is very small, the incineration process is difficult to achieve stable combustion, dioxin emission level is difficult to reach the emission level of 0.1ngTEQ/m3.
Compared with Japan's hierarchical control, China's new standards are more stringent. For example, Japan's corresponding standards provide that the size of 2 tons / hour ~ 4 tons / hour of the implementation of the furnace 1ngTEQ / m3 requirements; the size of less than 2 tons / hour of the implementation of the furnace 5.0ngTEQ / m3 requirements.
In addition to hydrogen chloride, heavy metals in the 'cadmium Thallium, lead and others, GB18485-2014 emission concentration limits for various other pollutants have been comparable to the EU.
Dioxin-like substances are mostly in solid form at room temperature, so the flue gas dioxin-like substances are mostly attached to particulate matter, and the improvement of the dust removal efficiency also means the improvement of the removal rate of dioxin-like substances. Therefore, the new standard requires that the waste incineration plant flue gas dedusting facilities must use the highest dust removal efficiency of the bag dedusting technology .
The new standard significantly increases the emission limits for particulate matter in the flue gas, while also increasing the emission control requirements for dioxin-like substances and heavy metal substances. Countries around the world have adopted this level of emission limit configurations.
Shift from end-to-end control to process control
The control of carbon monoxide concentration, control of dioxin-like substances generated conditions; the use of "hourly average" and "daily average" combination of pollution control limits, the first time.
From end-to-end control to process control is a major feature of the new standard.
Traces of dioxins in the flue gas can not yet be real-time online monitoring, but can be speculated through some online monitoring data dioxin emissions. The carbon monoxide content and soot content in the flue gas are closely related to the combustion efficiency and dust removal efficiency, which are also important factors affecting the dioxin content .
The revised new standard will be the concentration of carbon monoxide as a process control indicators, it is through the control of carbon monoxide concentration, control the conditions for the generation of dioxin-like substances, so as to control the large amount of dioxin production.
Improving the combustion efficiency of the incinerator can effectively incinerate the dioxin-like substances contained in domestic waste and the precursor substances that may resynthesize dioxin-like substances in the flue gas, so as to reduce the chances of resynthesis of dioxin-like substances.
Some studies have shown that when the incinerator flue gas carbon monoxide concentration is reduced to 100mg/Nm? below, the concentration of dioxin-like substances in the flue gas will be greatly reduced, greatly reducing the pressure of the subsequent dioxin-like substances removal facilities to ensure compliance with the standard provides a good basis. The world's standards have adopted this value as the incinerator operating conditions control indicators .
Newly revised standards, domestic waste incineration plant should be set up incinerator operating conditions of online monitoring devices, monitoring results should be used electronic display boards for publicity and with the local environmental protection department monitoring center network. Incinerator operating conditions online monitoring indicators should include at least the flue gas concentration of carbon monoxide, oxygen concentration and burning temperature in the furnace .
In addition, based on the characteristics of domestic garbage itself, its moisture content, composition, etc. with time and regional changes will have irregular changes. This brings a lot of trouble to the working conditions and pollution control of the waste incinerator. Irregular changes in working condition parameters and flue gas emission concentration lead to frequent exceedance of standards and penalties.
In order to maximize the feasibility and operability of the standard, and to encourage enterprises to be honest and law-abiding, the new standard makes reference to the international practice, adopts the combination of "hourly average" and "daily average" pollution control limits, and sets up a sub-hourly
For example, during the startup, shutdown and accident phases, the concentration of pollutants in the flue gas increases significantly, and the environmental impact of this phase is unavoidable, among which the greatest impact on human health is dioxins, which are mainly discharged in the form of enrichment in the form of flue dust particles. Therefore, the start-up, shutdown and accident phases mainly control the concentration of particulate matter emissions and indirectly control dioxin-like substances emissions. With reference to the EU standard requirements, the concentration of particulate matter in these stages to implement the 150mg/m?limit .
Medical waste and leachate have a home
The new incineration standards allow treated medical waste to be incinerated in a domestic waste incinerator, which can make full use of the high calorific value of medical waste characteristics and reduce the risk of environmental pollution; landfill and incineration plant leachate is treated differently.
GB18485-2001 stipulates that "hazardous waste shall not enter the domestic waste incineration plant treatment", all medical waste and hazardous waste are rejected, but inadvertently caused more environmental hazards.
The new standard allows treated medical waste to be incinerated in a domestic waste incinerator, which makes full use of the high calorific value of medical waste and greatly reduces the risk of environmental pollution.
Cities are building medical waste disposal facilities, and the most common disposal technology is incineration. However, the scale of dedicated incinerators for medical waste is small, usually ranging from 10 tons/day to 30 tons/day, and small furnaces smaller than 10 tons/day are also common.
Small furnaces are difficult to control pollution, and most of the medical waste is highly chlorinated and prone to produce dioxin-like substances during incineration, which creates a very high environmental risk. In view of this, some cities have built non-incineration treatment facilities such as high-temperature cooking and sterilization to deal with medical waste, but the destination of the treated waste has become a new problem .
There have been a number of environmental pollution incidents caused by unregulated treatment of waste leachate, and the new standard has clear and feasible provisions for the treatment of waste leachate.
Since most of the domestic waste incineration plants and landfills are close to each other or have a closer cooperation relationship, the new standard stipulates that the domestic waste leachate and vehicle washing wastewater should be collected and processed in the domestic waste incineration plant, or sent to the domestic waste landfill leachate treatment facilities for treatment to meet the corresponding requirements of the "pollution control standards for domestic waste landfills" (GB16889) after treatment. After treatment to meet the corresponding requirements of the "pollution control standards for domestic waste landfills" (GB16889), it can be discharged directly, or it can be sent to the municipal sewage treatment plant with secondary treatment through the sewage pipe network or by means of closed conveyance under the premise of meeting certain conditions.
This requirement of the new standard is quite different from GB16889. Because GB16889 requires that all landfills must treat their own leachate. On this difference, Wang Qi explained: "There is a difference between landfill leachate and waste incineration plant leachate." The former is not only a large amount, the amount generated fluctuates greatly with the seasons, and the water quality fluctuations are also relatively large; while the latter is correspondingly more stable, and the amount is small. Taking into account the needs of technology, economy, environment and social management, it can be treated through sewage treatment plants.
In addition to the above, compared with the current standard, the new standard scope of application is also different. The new standards provide for domestic sewage treatment facilities generated sludge and general industrial solid waste dedicated incineration facilities for pollution control control standards with reference to the implementation of domestic waste incineration pollution control standards .
For the use of industrial kilns co-disposal of domestic waste, reference to foreign countries, especially the United States experience, if the quality of incineration of domestic waste is not more than the total into the furnace (kiln) 30% of the total mass of materials, the implementation of the corresponding pollution control standards for industrial kilns; when added to the quality of domestic waste is more than the quality of the total into the furnace (kiln) 30% of the total mass of materials, the implementation of this standard.
In order to make the public incineration facilities more assured, while strengthening supervision, the new standards also increased the operating conditions and flue gas emissions online monitoring requirements, facilities flue gas purification system should be installed online monitoring equipment, can be detected at any time and record the furnace temperature, O2, CO and other operating conditions and flue gas particulates, HCl, SO2, NOX and other pollutants in the emission data; and set up a public notice boards, displaying test data, and the establishment of the plant outside the And set up a signboard outside the plant to display the test data, instantly accept public supervision. At the same time, the system is networked with the monitoring center of the local environmental protection administrative department to accept the supervision and management of the law enforcement department. In addition, the frequency of self-monitoring and supervisory monitoring of enterprises is also required .