????Is the garbage landfilled or burned? Why build a new waste incineration plant? Will incineration bring dioxin emissions? Recently, the publicity of the project of Jiu Feng Waste Incineration Plant in Yuhang District of Hangzhou attracted the attention of many citizens.
????A new waste incineration plant project is planned around Jiu Feng, which is currently in the stage of site selection and demonstration.
????Today’s Hangzhou, like Guangzhou a few years ago, faces the situation that there is nowhere to fill the garbage: on the one hand, the "garbage siege" has entered the countdown; On the other hand, after years of development, waste incineration power generation has developed into a new industry with the characteristics of high-tech industries in China, and has been included in the national priority development of high-tech industries.
????In the interview, the heads of relevant departments and industry experts are conveying the message that at the government level, the construction of garbage disposal infrastructure is facing irresistible urgency.
????The alarm of Hangzhou garbage siege has sounded.
????Domestic waste disposal capacity has not increased for 7 years.
????According to the statistics of Hangzhou Urban Management Committee, in recent years, the annual growth of domestic garbage in the main urban area of Hangzhou is about 10%, while the garbage disposal capacity has not increased in seven years. This year, according to the Hangzhou Municipal Urban Management Committee’s Supervision Report on the Disposal of Domestic Solid Waste, the maximum daily domestic waste disposal in March has reached 10,959 tons.
????Take Tianziling, a large-scale landfill in Hangzhou, as an example. At that time, the design plan was to landfill 2,671 tons of garbage every day, but this year, the maximum daily landfill volume has reached 5,408 tons, more than double the design capacity. When planning in 2007, the design capacity of Tianziling can be used for 24 and a half years, but according to the current amount of garbage, it is estimated that it can only be used for another 5 years.
????In other words, the alarm of Hangzhou garbage siege has sounded, and it is urgent to build a new garbage treatment plant. Otherwise, it will face the crisis that thousands of tons of garbage can’t be treated every day.
????At present, there are three commonly used domestic waste terminal treatment methods at home and abroad: sanitary landfill, composting and incineration for power generation. The first two types occupy a lot of land, and if they are not handled properly, there are also problems of pollution to soil and crops. And with the process of urbanization, on the one hand, there is no land for landfill, on the other hand, as an important strategic guarantee resource for urban garbage disposal, the landfill storage capacity has decreased sharply, which is unsustainable.
????As a widely used municipal solid waste treatment method in developed countries, waste incineration power generation is most in line with the three principles of "harmlessness, reduction and resource utilization", and it is inevitable that waste incineration power generation will become the first choice of municipal solid waste treatment methods in China.
????According to Zhang Shukong, director of the solid waste center of Hangzhou Urban Management Committee, Hangzhou’s garbage disposal supervision department, "The garbage disposal in the main city of Hangzhou is mainly based on landfill, supplemented by incineration, and 60% of domestic garbage is landfilled. In Beijing, Shanghai and Guangzhou in China, including abroad, there are two main ways of garbage disposal, the mainstream is incineration, supplemented by landfill. "
????Weng Shilong, a senior engineer at Hangzhou Environmental Protection Research Institute, believes that "incineration technology is mature and management norms are relatively perfect, which can effectively reduce and recycle domestic waste."
????Jiu Feng incineration plant is built in the valley.
????Then, where is the Jiu Feng waste incineration plant project in the site selection demonstration stage?
????According to reports, this location is located in a plot near Lin’ an, Zhongtai Street, Yuhang. It used to be a mine, which is remote, relatively closed and has fewer households.
????In the interview, relevant parties said that there are hundreds of thousands of people living in the west of Hangzhou, and they have supporting facilities such as transportation facilities and sewage treatment. At present, "there is only one garbage incineration plant in this block, and the construction time is relatively early. The current processing capacity can’t keep up with the garbage production in the west block. Therefore, it is urgent to build a new waste incineration plant. "
????Dioxins produced by garbage incineration
????Can be completely controlled within the range of safe discharge.
????People are mainly worried about dioxin emissions in garbage incineration. The so-called dioxins, in fact, are short for dioxins, which refer to two categories with similar structures and properties, including many congeners or isomers, with a total of 210 organic compounds, but only a few of them are considered toxic.
????In this regard, Dr. Huang from the Institute of Thermal Energy Engineering of Zhejiang University introduced that the new waste incineration project in Hangzhou will adopt advanced incineration technology, and the smoke emission control will refer to the EU 2000 standard, with the dioxin emission standard of 0.1ngTEQ/Nm3. Due to the development of related treatment technologies, toxic substances such as dioxins produced by garbage incineration can be completely controlled within the scope of safe discharge.
????The modern waste incineration power plant adopts mature "3t" (turbulence, temperature, time) technology to control dioxins. One is that if the temperature in the incinerator is kept above 850 degrees and the flue gas stays in the incinerator for more than 2 seconds, dioxins can be completely decomposed. Secondly, the flue gas is treated by the most advanced way, and the unit dioxin emission is controlled within 0.1 nanogram, reaching the EU 2000 standard.
????Online monitoring data
????It will be played in real time on the LED screen of the factory.
????After the completion of the feasibility study in the early stage of construction, the project of Jiu Feng Waste Incineration Plant will go through the approval stages including site selection and environmental assessment before it can start construction. Every link will be implemented in accordance with the law and regulations, and citizens can put forward opinions and suggestions on the project in the later stages.
????The newly-built waste incineration plant is transparent and open to the public and the media. In the future, Jiu Feng Waste Incineration Plant will invite the surrounding residents to enter the plant as environmental protection volunteers to supervise the production process and emissions of waste incineration at any time.
????On-line monitoring data will be played on the LED screen of the factory in real time, and surrounding residents and other citizens will be invited to enter the factory as environmental volunteers to supervise the operation status and emission indicators of all equipment.
????After the new project is put into operation, it will be closely supervised. First, it will be supervised by government departments, with 24-hour online data monitoring and transmission, and the third-party entrusted management of the whole monitoring equipment. Secondly, the enterprise will strictly supervise itself and accept the supervision of the media and citizens.
????-Press attachment
????Develop modern garbage incineration power generation
????In fact, it is a measure to reduce dioxin emissions
????Practice at home and abroad shows that garbage incineration power generation is an efficient process of garbage harmless treatment and resource utilization, and it is the most effective method for large-scale garbage treatment.
????According to WHO, due to the ubiquity of dioxins, all people are exposed to the environment, and there is a certain degree of dioxins in their bodies, which results in the so-called body burden. Generally speaking, exposure to normal environment will not affect human health. However, due to the high potential toxicity of these compounds, efforts should be taken to reduce the current environmental exposure.
????Foreign research also shows that the dioxin emitted by 1 ton of garbage burning in the open air or spontaneous combustion in landfill is thousands of times that emitted by the same amount of garbage through modern incineration.
????Therefore, the development of modern waste incineration power generation is actually a measure to reduce dioxin emissions. The reconstruction, expansion or new construction of waste incineration plant can completely realize the perfect combination of technology, ecology, art and commerce and become the landmark landscape of the city.
????Dr. Zhejiang University interprets the whole process of waste incineration
????Exhaust emission has zero burden on the surrounding environment.
????Dr. Huang from the Institute of Thermal Energy Engineering of Zhejiang University explained the whole process of garbage incineration in detail.
????Clean and direct transportation (airtight)-garbage incineration plant-temporary storage in garbage pit (controlling slight negative pressure to prevent air from entering and odor from overflowing, and going through natural fermentation process to separate some moisture)-sending to incinerator (garbage is dried, pyrolyzed/gasified, burned and burned out, and oxygen needed in the incineration process is extracted from the garbage warehouse)-generating high-temperature flue gas after incineration (high-temperature flue gas passes through). During the treatment process, various physical and chemical methods will be used to remove various acidic gases and particulate pollutants, as well as dioxins and heavy metals)-emissions (the flue gas components in the gas are mainly carbon dioxide, water vapor and nitrogen).
????"As long as the equipment is properly selected, the process management is emphasized, and the tail gas monitoring is done well, the emission of the garbage incineration plant should be said to be zero burden to the surrounding environment." Dr. Huang said.
????It is reported that the new project will simultaneously build a landfill leachate treatment system, which can treat landfill leachate to the standard of reclaimed water reuse, and the treated reclaimed water will be used for cooling the generator set, which can realize zero discharge of landfill leachate and has nothing to do with the surrounding surface water and groundwater.
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