What are the methods of garbage disposal?

Question 1: What are the methods of garbage disposal? At present, the urban domestic waste treatment methods widely used at home and abroad mainly include sanitary landfill, high-temperature composting and incineration. The proportions of these three main waste treatment methods vary due to factors such as geographical environment, waste composition, and economic development level. .

Since the composition of urban waste is complex and is affected by factors such as the level of economic development, energy structure, natural conditions, and traditional habits, the treatment of urban waste generally varies according to national conditions, and is often different in a country. Regions also use different approaches, making it difficult to have a unified model. But in the end, the treatment goals are harmlessness, resource utilization, and reduction. There are landfill, incineration, composting, comprehensive utilization and other methods, with a high degree of mechanization and forming systems and complete sets of equipment. Foreign treatment methods have the following trends: (1) Due to the increasing shortage of energy and land resources in industrialized countries, the proportion of incineration treatment is gradually increasing; (2) Landfill method has always occupied a large proportion as the final disposal method of garbage; (3) Agricultural type Most of the developing countries mainly use compost; (4) Some other new technologies, such as pyrolysis, sea reclamation, mountain landscaping and other technologies, are making continuous progress.

Incineration is a widely used urban waste treatment technology. Large-scale waste incineration treatment systems equipped with heat energy recovery and utilization devices are gradually becoming the mainstream of incineration treatment because they comply with the requirements for energy recovery. The wide application of incineration technology is not only due to the developed economy, strong investment power and high calorific value of waste, but also due to the maturity and advanced incineration technology and equipment. Various incineration devices and new incinerators are developing in the direction of high efficiency, energy saving, low cost and low pollution, and the degree of automation is getting higher and higher. At present, the technical countermeasures for urban waste treatment in my country are: focusing on sanitary landfill and high-temperature composting technology, and promoting the development of incineration technology in cities with conditions, especially in economically developed coastal areas. In recent years, cities have begun to carry out basic and applied research on waste incineration treatment, and have developed NF series reverse combustion type, RF series pyrolysis type, HL series rotary small waste incinerators and a number of hospital waste-specific incinerators. And a number of small and medium-sized urban simple incineration plants (stations) have been built.

With the development of my country's economy and the improvement of people's living standards, the content of combustibles and combustibles in urban garbage has increased significantly, and the calorific value has increased significantly. Generally, after pretreatment such as classification and sorting, The calorific value of waste is close to that of urban waste in developed countries. Therefore, some cities in our country, especially in economically developed coastal areas, already have the basis for developing incineration technology.

Question 2: What are the main methods of harmless disposal of garbage? The three main treatment methods are sanitary landfill, composting, and incineration

The garbage disposal methods in our city's garbage disposal sites are the same as those in other countries in the world. Sanitary landfill, composting, and incineration are the main methods, among which Most urban waste is processed by piles and simple landfills. Sanitary landfills, mechanized composting, and incineration are also used in some applications.

Landfill: For a long time, most cities in China have used methods such as open-air stacking, natural ditch filling, and pit filling to handle domestic waste, which can only achieve general anaerobic treatment. However, in recent years, the construction of landfills has become increasingly perfect, and a number of higher-level landfills have been built one after another, such as in Hangzhou, Guangzhou, Suzhou, Beijing, Chengdu, Baotou and other cities based on the actual situation of the city. A relatively complete sanitary landfill has been established. At the same time, technology for the recovery and utilization of biogas produced in landfills has also been developed. At present, landfill is still the most important harmless treatment method for urban landfill waste in our city.

Composting: In recent years, our city’s waste treatment and composting has developed rapidly. The "secondary fermentation process" has been applied since the 1980s. Due to the adoption of forced sealing, the fermentation cycle has been shortened, composting machinery has also been increasingly improved, and production has tended to be industrialized. Nationally, a mechanized waste composting production line suitable for China has been designed on its own, but many cities still have a considerable number of simple waste composting plants.

Incineration: Incineration technology is the most effective way to detoxify, reduce, and recycle garbage, and is the development method for future garbage treatment.

Question 3: What are the best ways to dispose of domestic waste? At present, the country's soil resources are very tight, so although landfilling is a common method, it is not a long-term solution. Therefore, the most important method at present is still incineration, but it is not the optimal method.

The best method should be composting. Although this method is good, there are no sales channels for the fertilizer obtained after composting, and people are unwilling to buy it. Therefore, the optimal method does not mean that it can be promoted nationwide.

Basically there are three main treatment methods

1. Landfill treatment

Landfill is an effective method for disposing of large amounts of municipal solid waste, and it is also the As the final disposal method for waste treatment process residues, direct landfill method is currently commonly used in my country.

The so-called direct landfill method is to fill the garbage into a prepared pit, cover it and compact it, so that it can undergo biological, physical and chemical changes, decompose organic matter, and achieve reduction and harmlessness. Purpose.

Tianjin City used garbage to pile up mountains on the south side of the water park to create an artificial environment and turn harm into benefit. The project covers an area of ??nearly 800,000 square meters, and the garbage and construction waste soil are mixed at a ratio of 1:1 as Necessary measures have been taken to collect the soil source from the mountains, to deal with the leachate and biogas produced by fermentation, and to stabilize the hillside.

Kansas City in the United States is a small city with a small population. The city is surrounded by vast countryside. A landfill was built in a low-lying area of ??hilly land far away from the city. In order to prevent To prevent secondary pollution, take the following measures:

(1) Lay an anti-seepage layer at the bottom and around it;

(2) Lay it in layers, that is, pile up a layer of garbage, and then The cover soil is compacted, and according to reports, gas and water pipes are installed on some garbage dumping floors to utilize the generated biogas.

There is a land with dense woods and luxuriant flowers and plants in Koto District, Tokyo, Japan. People call it "Dream Island". Dream Island is all made of garbage.

However, most of the garbage in many cities in my country is still piled in the open without any protective measures. Every garbage dump has become a source of pollution. Mosquitoes and flies are infested, rats are infested, and the stench is all over the sky. A large amount of garbage and sewage seep into the ground from the surface, causing serious pollution to the urban environment and underground water sources. Shenyang City once drilled and sampled 10 of the 35 landfills and analyzed garbage fault samples and groundwater quality. The analysis results found:

1. The groundwater quality has deteriorated, the pollution is serious, and the water is turbid and smelly. Anaerobic Escherichia coli was detected in the water;

2. Toxic and harmful substances were detected in all garbage fault samples. Every day in Shanghai, tens of thousands of tons of garbage are transported to suburban areas and piled up on the seaside. Garbage mountains 20 to 30 meters high rise from the ground, causing serious pollution to the surrounding environment.

Landfill disposal is the most common method of garbage disposal. Its biggest features are low disposal cost and simple method, but it can easily cause secondary pollution of groundwater resources. As the amount of urban garbage increases, there are fewer and fewer suitable landfill sites close to the city. The opening of long-distance landfill sites has greatly increased the cost of waste discharge, and such high costs are even unbearable.

2. Incineration treatment

The incineration method is a method of placing garbage in a high-temperature furnace to fully oxidize the combustible components. The heat generated is used for power generation and heating. The waste-to-energy system jointly developed by Westinghouse and O'Connell in the United States has been successful. When burning garbage, the incinerator of this system can turn garbage with a humidity of 7% into dry solids for incineration, with an incineration efficiency of more than 95%. At the same time, the high temperature on the surface of the incinerator can convert heat energy into steam, which can be used for heating and air conditioning equipment. and steam turbine power generation. The main technical indicators of some incineration plants in the United States are listed in Table 1.

my country's Shijiazhuang City has built an incineration station, and the Shenyang Environmental Science Institute has introduced Japanese garbage incineration devices to harmlessly treat special garbage from hospitals and other units. The residual ash generated during the incineration process accounts for about 10% of the waste before incineration. 5% of the weight of biological waste is generally high-quality phosphate fertilizer. In recent years, my country has paid more and more attention to the renewable energy technology generated by waste incineration power generation.

The advantages of incineration treatment are good reduction effect (the volume of the residue after incineration is reduced by more than 90%, and the weight is reduced by more than 80%) and the treatment is thorough. However, according to reports in the United States, the construction and production costs of incineration plants are extremely expensive. In most cases, the value of the electricity generated by these equipment is far lower than the expected sales, leaving local governments with huge financial losses. Since garbage contains certain metals, incineration is highly toxic and creates secondary environmental hazards. Incineration treatment requires the calorific value of the garbage to be greater than 3.35MJ/kg. Otherwise, combustion accelerants must be added, which will increase operating costs to a point that is unbearable for ordinary cities.

3. Composting treatment

Pile domestic waste into piles, keep it at 70°C for storage and fermentation, and use the ability of microorganisms in the waste to decompose...gt; gt;

Question 4: What are the methods for municipal waste disposal? (1) Compression processing. For some municipal waste with low density and large volume, the volume can be reduced after pressure and compression treatment, making it easier to transport and landfill. Some waste can become high-density inert materials and construction materials after compression treatment. (2) Landfill. We can make use of the basic conditions provided by various places and adopt different landfill methods to meet the requirements of operation and consumption. Landfills can not only handle the city's mixed waste, but also can consume leftover materials from other waste treatment processes and waste that cannot be recycled. (3) Garbage incineration. The heat energy generated after waste incineration can be used to produce steam or electricity, and can also be used for heating or production needs. According to calculations, for every 5 tons of garbage, 1 ton of standard fuel can be saved. However, waste incineration plants must be equipped with smoke and dust removal devices to reduce the emission of pollutants into the atmosphere. (4) Compost. Composting is a biochemical process that uses microorganisms to decompose the organic matter of garbage, releasing carbon dioxide, water and heat, and generating humus at the same time.

Question 5: How many ways are there to dispose of garbage? Food waste: refers to the waste generated by people in the process of buying, selling, storing, processing, and eating various foods. This type of garbage is highly corrosive, decomposes quickly, and emits a foul odor.

General garbage: including waste paper products, waste plastics, rags and various textiles, waste rubber, broken leather products, waste wood and wood products, broken glass, scrap metal products and dust, etc. General garbage and food waste are the main objects that can be recycled in municipal waste.

Construction waste: including soil, stones, concrete blocks, broken bricks, waste wood, waste pipes and electrical waste, etc. This type of waste is generally handled by the construction unit itself, but a considerable amount of construction waste is often included in urban garbage.

Garbage cleaning: including waste in public trash cans, cleaning materials in public places, waste after damaged roads, etc.

Hazardous waste: including dry batteries, fluorescent tubes, thermometers and other chemical and biological hazards, flammable and explosive items and waste containing radioactive materials. This type of garbage generally cannot be mixed with ordinary garbage.

There are three main methods for harmless disposal of garbage:

Landfill: Landfill waste requires low investment and large processing capacity; the technical requirements are not high. But its permanent footprint is large and its potential to cause pollution is high. In developed countries such as the United States, there have been incidents of landfills causing pollution decades later.

Composting: Treating garbage with compost can turn garbage into organic fertilizer. However, this kind of garbage fertilizer has low fertilizer efficiency, limited sales, and little room for development.

Incineration: Incineration of garbage has the advantages of recovering heat energy and reducing the amount of garbage most thoroughly (the volume of garbage is reduced by 80 to 95% after incineration), but this method is costly.

It would cost approximately RMB 700 to 800 million to build an incinerator with a daily capacity of 1,000 tons of garbage and ancillary heat recovery equipment.

Question 6: How many methods are there for garbage disposal? 1. Basic Current Situation China’s garbage disposal started late, and its ability to harmlessly treat garbage is low. There has been a serious situation where garbage surrounded the city. In recent years, China's environmental sanitation industry has made great progress, which has improved the level of urban garbage disposal and alleviated the phenomenon of garbage surrounding cities. According to statistics in 1994, there are about 380,000 sanitation employees in cities across the country, and about 34,400 various sanitation machinery. The garbage treatment rate reaches 35.8%. 609 harmless treatment sites have been built, and the harmless treatment capacity of garbage and processing rates have grown significantly in recent years. Major cities in China have established environmental sanitation research institutions and carried out research on urban waste treatment technology and equipment. During the "Eighth Five-Year Plan" period, the state allocated nearly 10 million yuan and loaned tens of millions of yuan to carry out scientific research, development and demonstration projects for urban waste composting, landfill, incineration and resource utilization. 2. Application of garbage treatment technology The management of urban garbage is a systematic project, including garbage collection, transportation, transfer, processing and resource utilization. 1. Collection of urban garbage Most cities and towns in China currently use mixed collection methods for garbage collection (except hospital garbage). The garbage operation methods and equipment used mainly include the following: fixed garbage bins, garbage storage and collection, movable garbage bins, garbage collection, trash can collection, and plastic bag collection. Sealed container collection and ground garbage station collection, etc., most cities can achieve timely garbage collection and keep the environment in residential areas clean. 2. From an overall perspective on urban garbage transportation, the mechanized collection and transportation rate of urban garbage in China is low. The labor intensity of sanitation workers is high, manual operations are insufficient, and the equipment performance is poor. About 40% of the sanitation equipment and vehicles in the country need to be updated, and about 10% of the sanitation equipment and vehicles need to be updated every year. As a result, 10 million tons of urban garbage cannot be transported to treatment sites in time. 3． The current garbage treatment sites and resource utilization technologies used in urban waste treatment in China are the same as those in other countries in the world. They mainly use methods such as sanitary landfill, composting, and incineration. Most of the urban waste is processed by stacking, simple landfill, sanitary landfill, and mechanization. Composting and incineration are also partially used. China's urban domestic waste treatment methods mainly include waste-based building materials (bricks) and comprehensive utilization. (1) Application of landfill technology For a long time, most cities in China have adopted methods such as open-air stacking, natural ditch filling, and pit filling. Only general anaerobic treatment can be achieved. However, in recent years, the construction of landfills has become increasingly perfect, and a number of higher-level landfills have been built one after another. Cities such as Hangzhou, Guangzhou, Suzhou, Beijing, Chengdu, and Baotou have established relatively complete landfills based on the actual conditions of the city. of sanitary landfills. At the same time, the technology for recycling and utilizing biogas produced in landfills has also been developed. At present, landfill is still the most important method of harmless treatment of urban landfill waste in China. (2) Application of composting technology In recent years, China's garbage composting has developed rapidly. The "secondary fermentation process" has been applied since the 1980s. Due to the adoption of forced sealing and aerobic fermentation, the fermentation cycle has been shortened. The composting machinery has become increasingly perfect and production has tended to be industrialized. At present, cities such as Wuxi, Changzhou, Tianjin, Shenyang, Beijing, and Wuhan have designed their own mechanized garbage composting production lines suitable for China, and many cities also have a considerable number of simple garbage composting plants. (3) Application of incineration treatment technology Research on waste incineration technology in China started in the mid-1980s. Incineration technology is the most effective way to harmless, reduce and recycle waste, and is the future development method of waste treatment. Currently, China Only a few cities such as Shenzhen, Leshan, and Xuzhou have established waste incineration treatment plants and conducted demonstration tests of incineration power generation. The system is operating well, but the scale is small and the daily processing capacity is low. Large and medium-sized cities such as Beijing, Shenyang, Shanghai, Beihai, and Guangzhou are currently planning to build larger-scale waste incineration sites.

Question 7: What are the methods for disposing domestic waste now? Depending on the level of development, different places have different ways of dealing with domestic waste. Therefore, for now, the way of dealing with waste in this region is relatively scientific.