One, China's garbage generation and treatment profile:
Ministry of Environmental Protection, "Environmental Protection Acceptance Technical Specifications for the Completion of Construction Projects," the preparation group recently confirmed that: the country's large and medium-sized cities about 2/3 of the country has been caught up in the garbage surrounded by 1/4 of the city is not suitable for the place of the garbage pile. Statistics show that in recent years, with the acceleration of urbanization and the improvement of people's living standards, China's urban living garbage average annual growth rate of nearly 9%, per capita annual production of living garbage amounted to 440kg, Beijing and other cities, the increase is even higher than 15% -20%. At present, China's municipal domestic waste generation is about 146 million tons, and the cumulative amount of municipal waste piled up is more than 7 billion tons, covering an area of more than 500 million square meters.
Data from the 2013 China Statistical Yearbook: by the end of 2012, there were 540 landfills nationwide*** with a landfill capacity of 311,000 tons per day, totaling 105.125 million tons for the year. About 72.6% of urban domestic waste is disposed of by landfill.
The main environmental impacts generated by landfill disposal of domestic waste include the unique odor gas pollution emitted by the waste, landfill gas pollution generated by the degradation and fermentation of the waste during the landfill process, leachate pollution with high concentration of pollutants generated by the physical, chemical, and biological roles of the garbage during the process of garbage stacking and landfill, the leaching of rainwater, scouring, and soaking of groundwater, and pollution by the concentration of flies caused by the bad smell of the landfill site. Pollution caused by the concentration of malodor in landfills, etc. Landfill technology, as the traditional treatment and final disposal method for domestic waste, is still the main method of domestic waste disposal prioritized in China and most countries in the world. The overall level of domestic waste landfill in China is still in the primary stage.
Second, the principle of comprehensive waste management:
To suit local conditions, scientific guidance. Considering the actual situation of different regions, strengthen the classification guidance, adhere to the combination of centralized and decentralized treatment. In accordance with the principle of "minimization, resource utilization, harmlessness", the selection of advanced and applicable technology according to local conditions, the conditions of the region should give priority to the use of incineration and other resource treatment technology.
China's domestic garbage can be generally divided into four categories: recyclable garbage, kitchen garbage, hazardous garbage and other garbage. Currently, the commonly used waste treatment methods are: comprehensive utilization, sanitary landfill, incineration and composting.
1, recyclable waste mainly includes: waste paper, plastic, glass, metal and cloth five categories.
1) Waste paper: mainly including newspapers, periodicals, books, all kinds of wrapping paper, office paper, advertising paper, cardboard boxes, etc., but note that paper towels and toilet paper are too water-soluble to be recycled.
2) Plastic: mainly including various plastic bags, plastic packaging, disposable plastic lunch boxes and cutlery, toothbrushes, cups, mineral water bottles, toothpaste skins and so on.
3) Glass: mainly includes a variety of glass bottles, broken glass pieces, mirrors, light bulbs, thermos flasks and so on.
4) Metallic: Mainly includes cans, can boxes, etc.
5) Fabrics: mainly including discarded clothes, tablecloths, washcloths, school bags, shoes, etc.
Recycling through integrated treatment can reduce pollution and save resources. For example, each recycled 1 ton of waste paper can make 850 kilograms of good paper, saving 300 kilograms of wood, than the same amount of production to reduce pollution by 74%; each recycled 1 ton of plastic beverage bottles can be obtained from 0.7 tons of secondary raw materials; each recycled 1 ton of scrap iron and steel can be smelted 0.9 tons of steel, smelting with ore than the cost of savings of 47%, 75% reduction in air pollution, reducing 97% of the water pollution and solid waste.
2, kitchen waste, including: leftovers, bones, vegetable roots and leaves, peels and other food waste, biotechnology treatment, each ton can produce 0.3 tons of organic fertilizer.
3. Hazardous waste includes: waste batteries, waste fluorescent tubes, waste water silver thermometers, expired medicines, etc., which require special and safe treatment.
4, other garbage includes: in addition to the above categories of garbage, masonry ceramics, slag, bathroom waste paper, paper towels and other difficult to recycle waste.
Three, urban living waste comprehensive treatment process:
1, urban living waste resource treatment process introduction
Based on the analysis of living waste treatment methods, Zheng'an County living waste treatment process will be used to "rapid, harmless, fully resourceful, industrialized, intelligent" waste treatment process. Intelligent" garbage treatment process. The advantages of the treatment process are as follows:
1) solved the problems of large floor space, short use time, long occupation time, pollution of groundwater, pollution of soil, pollution of the atmosphere of the sanitary landfill process of municipal domestic garbage;
2) solved the problems of expensive operation cost of pure incineration and pure incineration power generation process of garbage and the difficulty of dealing with the toxic gases produced by incineration;
3) Solve the composting process of poor quality fertilizer is difficult to resource, compost treatment plant flies and mosquitoes breeding, damage to the health of the surrounding people.
2, city life garbage sorting workshop process description:
City life garbage through the garbage transfer station and garbage trucks into the garbage sorting workshop, after weighing, garbage trucks into the closed garbage sorting workshop will be unloaded into the garbage pit with a volume of 1,800m3, unloading spray deodorizer. The garbage in the garbage storage pit is loaded into the skirt plate feeder by the grab of bridge-type double girder crane, and is evenly transported to the 120mm crusher through the belt conveyor and electromagnetic iron remover (the electromagnetic iron remover will partially recover the metal), which can crush all the large garbage and bagged garbage in the garbage (granularity is larger than 400mm and the crushing rate is 99%). After crushing, the garbage with particle size from 0 to 120mm enters into the drum garbage sorter, and the kitchen organic garbage and part of the sandy garbage (under sieve) sorted out by the drum garbage sorter goes directly into the crusher after the electromagnetic iron remover removes the iron (the crushing particle size is controlled to be less than 30mm), and the crushed kitchen organic garbage and part of sandy garbage enters into organic fertilizer workshop through the belt conveyor for the production of organic fertilizer. Organic fertilizer (can separate 75-90% of the organic matter in the garbage). The light garbage sorted out by the roller garbage sorting machine (screened material) enters the positive pressure sorting machine for sorting. In the positive pressure sorting machine, the incoming garbage meets with the flat airflow vertically and is sorted according to the different specific gravity and different landing points. The heavy products (wood, rubber, textile, etc.) sorted out by the positive-pressure sorting machine enter the electromagnetic iron remover to remove iron, and the heavy products after removal of iron are crushed by the crusher as combustible materials and enter the gas production workshop to produce gas. Positive pressure sorting machine sorted out (light products) into the photoelectric sorting machine for further sorting, photoelectric sorting machine sorted out impurities (leaves, paper, etc.) and heavy products mixed into the gas production workshop gas production.
The waste plastics sorted out by the photoelectric sorting machine are sent to the wood-plastic workshop through the belt conveyor to be cleaned, pelletized and mixed with wood powder to produce wood-plastic plates or wood-plastic profiles.
Some of the sand and soil sorted out is mixed with combustible materials and then sent to the gas production workshop for gas production. The slag after over-firing goes into the building materials workshop to produce aerated concrete.
The crushed kitchen organic waste and part of the sandy soil waste enter the organic fertilizer workshop to produce organic fertilizer through the belt conveyor. In the organic fertilizer workshop, organic matter in the hydrolysis hydrothermal oxidation treatment process is thoroughly cooked, spray burst completely puffed up into powder, and inorganic materials such as sand and gravel, glass slag, etc., the volume did not change, so the spray burst of the material by the dryer drying, sieving machine sieve to become an organic fertilizer, i.e.: organic class of garbage all become the bottom of the sieve, inorganic materials all become the top of the sieve (sand and gravel, glass slag), through the sieve will be mixed into the Organic matter inorganic matter through the sieve will be mixed into the sorting out. This technology for the current domestic and foreign garbage sorting technology, organic and inorganic separation of thorough sorting technology, that is, "hot selection" technology.
3, processing methods:
1) easy degradation of organic matter, sludge, leachate - organic fertilizer (organic fertilizer workshop).
2) Sand and gravel type - make aerated concrete (building materials workshop).
3) Plastic type - cleaning, crushing and granulation and with straw sawdust production of wood-plastic products (wood-plastic workshop).
4) non-recyclable combustibles category - anaerobic gas production (pyrolysis gas production workshop).
5) waste batteries, metal objects category - recycling.
4, the main features of the integrated management of domestic waste:
Modern production line, according to the garden-type factory planning and design, three-dimensional layout, centralized control, computer management, visual monitoring, closed transport of materials, gas purification and discharge, wastewater is not discharged, to achieve cleaner production, in the garbage, out of the product, the indicators have reached the relevant national standards.
1) Fast: four hours out of the product, the day of the garbage, the day of the treatment, to achieve the day of production.
2) Harmless: fully enclosed operation, so there is no odor spillage; no plastic incineration, so there is no generation of harmful emissions or less generation of harmful emissions; high temperature and high pressure hydrolysis of organic hydrothermal oxidation treatment, so the sterilization is complete; treatment is fast, leachate generation is less or no leachate generation.
3) No residual: all the garbage is recycled, and the treatment is thorough.?
4) Strong adaptability? : Urban and rural living waste, vegetable farm waste, construction waste, medical waste, livestock manure, livestock sick carcasses, food industry waste, agricultural waste, traditional Chinese medicine industry waste, wastewater treatment plant sludge, waste leachate.
5) Small footprint: one-fourth of the composting method, one-sixth of the landfill method, and the land used can be used permanently.
6) Resourcefulness, high degree of industrialization: because of the former sorting classification thoroughly, so all recyclable materials recycling, while reducing the amount of waste incineration, but also reduces the amount of hazardous gases (especially to reduce the amount of incinerator dioxin generation, than the pure incineration process to reduce the amount of 100%).
7) advanced equipment: most of the main equipment for the years of field experience condensed, sublimation and development of patented equipment, low failure rate, the use of good results, especially suitable for China's national conditions of the treatment of municipal waste.
8) Energy recycling, garbage treatment of garbage, low treatment cost. Good economic efficiency, the output is much larger than the input.?
Fourth, the effect:
Construction of garbage treatment plant with comprehensive garbage treatment technology, mature technology, reliable process, significant economic benefits, small investment in the project, the construction cycle is short, the recovery time is fast, the main equipment is dominated by domestic patented equipment, reliable performance, affordable. No secondary pollution, high degree of resource utilization, its comprehensive treatment technology to produce products, because of its price, quality and other factors, the market prospect is broad, completely realized the "mixed is garbage, separate is resources"; "in is garbage, out is product" and resource recycling The concept of resource recycling. It will surely make due contribution to the improvement of human living environment, the construction of new socialist countryside, the construction of resource-based and saving society and the development of circular economy.
Hope to help you.