A refuse transfer station is a transfer station between the place of origin of the refuse (or a centralized location) and the treatment plant in order to reduce the transportation costs of the refuse removal process. Here, the garbage removed from each collection point is consolidated and loaded into large or other less costly delivery vehicles for onward transportation to the treatment plant. The transfer station has a capacity of 100-500 tons. The location and size of the transfer station is an important economic management issue in waste removal. Sometimes a transfer station is built in conjunction with a recycling site. In this case, the garbage transferred out has changed its original character and quantity, and become the residue after recycling.
China will subdivide municipal waste into four groups, namely, material waste group (including glass, magnetic or non-magnetic metals, waste paper, rubber, plastics), organic waste group (kitchen waste, bio-waste), inorganic waste group (furnace ash slag, bricks and mortar, ceramics, etc.), poisonous and hazardous waste group (waste batteries, waste fluorescent lamp tubes, pesticide containers, expired medicines, medical wastes, as well as waste television sets, telephones, computers and other waste electrical appliances of electronic waste).
China's urban garbage disposal started very late, in the 1980s. Before that, garbage was piled up in the open. According to the information from the Municipal Domestic Waste Disposal Committee of the China Environmental Protection Industry Association, before 1990, China's urban waste disposal rate was less than 2%. It is only after entering the 1990s that China's urban garbage disposal has improved continuously. in 1999, China's municipal cities were 668, *** there were 696 garbage treatment plants (fields), including less than 200 harmless treatment plants, the garbage disposal rate was 63.4%, and the harmless treatment rate was only 20.3%.
There are more than 700 harmless waste treatment plants in Chinese cities only, and the harmless waste treatment rate of Chinese cities is 52%. Waste disposal in Chinese cities first goes through collection. The collection of urban household garbage in China is basically a mixed collection. Although the Chinese government advocated for separate collection in 2002, the separate collection of garbage only accounts for 16% at present. There are three main ways of mixed collection, one is to place collection containers in fixed locations, such as residential neighborhoods, on both sides of the street, and in other public **** places. Specialized sanitation staff are responsible for collecting garbage from these containers every day. Second, there are fixed garbage collection stations in residential neighborhoods where residents can throw their household garbage to the garbage station every day. Thirdly, there are garbage lanes. In high-rise residential buildings in China, the garbage lanes are already designed when the building is built, and they run from the first floor to the top floor, so residents can throw their garbage into the garbage lanes, and sanitation personnel will take it away from the bottom floor. Collecting residents' garbage through garbage tunnels used to be the most common way of collecting garbage in residential areas. However, after the SARS outbreak in 2003, it was banned in many cities because it was conducive to the spread of bacteria. Cities such as Beijing, Guangzhou, and Shanghai have all mandated that new residential buildings do not have garbage lanes, and some cities have also closed garbage lanes in already built residential buildings and discontinued them.
The collected garbage is transported to the garbage transfer station by specialized garbage trucks. The garbage trucks are completely sealed. The garbage is transported to the transfer station for the first step of processing. It is first classified by a sorting machine into organic and inorganic materials, as well as utilizable and non-utilizable. Bulky waste is also compressed. After that, the waste is sorted and transported away.
From the transfer station out of the garbage, some are transported to the sanitary landfill, the garbage will be filled into the pit has been prepared with a good cover and compaction, so that it will undergo biological, physical and chemical changes, decomposition of organic matter, to achieve the purpose of reducing and harmless. Special pipes and impermeable layers are laid in these pits to collect the gas and leachate produced by the fermentation of the waste. The gas is burned, part of the leachate is purified and processed into water, which is used to clean the garbage vehicles as well as the dust on the ground, and part of the leachate is filtered to meet the national level standards before being discharged, without causing pollution to the environment. Others are transported to a composting plant, where they are composted and turned into hygienic, odorless humus, which is used as fertilizer for plants. Waste Transfer Station
Another portion is sent to incinerators for burning to fully oxidize the combustible components of the garbage, and the heat generated is used to generate electricity and heating. There are currently 140 waste-to-energy power plants built, under construction and in the process of being submitted for approval in China. One ton of garbage can generate 300 degrees of electricity, and the waste heat can also be used for heating. The Tianjin Shuanggang garbage power plant, which handles 1,200 tons of garbage per day, generates 120 million degrees of electricity annually, which is enough for 50,000 households to use electricity for one year, and is equivalent to saving 48,000 tons of standard coal. For recyclable garbage, it will be recycled and reused. In the process of dealing with garbage, China has formulated a number of relevant standards, such as the standards for the control of urban garbage for agricultural use, the standards for the harmless sanitation of feces, and the standards for the emission of incineration exhaust gas.
Among the waste treatment methods, incineration is slower to develop in China, mainly because of the lack of funds. The initial investment in incineration is large, and the construction of an incinerator with a daily capacity of 1,000 tons of garbage and ancillary heat recovery equipment requires about 700-800 million RMB. Moreover, because incineration produces dioxin gas when treating waste, many cities do not use incineration much except for the need to treat medical waste. Many cities use sanitary landfills, which are considered by environmental officials to be more suitable for China's national conditions.
According to the China Environmental Protection Industry Association (CEPIA) Municipal Waste Disposal Committee, 70% of China's municipal waste is disposed of by landfill, 20% by composting, 5% by incineration, and 5% by other methods (including open piles and recycling).