At present, there are three ways to dispose municipal solid waste in China: sanitary landfill, incineration and compost.Waste incineration has the advantages of less land use, more reduction and energy availability.In recent years, due to the shortage of land resources in the Yangtze river delta, pearl river delta and beijing-tianjin-hebei region, household waste incineration power generation has developed rapidly as an alternative landfill technology.Due to the high water content of kitchen waste, it will lead to low calorific value when it is mixed with other household waste for power generation. Moreover, after plastic and toxic and harmful wastes enter the incinerator, they will increase the emission of dioxins, heavy metals and other pollutants.Therefore, it is urgent to change the situation of mixed collection of municipal solid waste in China.
Sanitary landfill technology occupies more land.With the development of urbanization in China, the densely populated central and eastern regions and large cities are facing the situation of “no land to bury”, so incineration power generation is the main choice of waste treatment technology in the future.However, sanitary landfill still plays an auxiliary role in garbage disposal in these areas: disposal of residual materials generated after incineration, and some construction wastes that are not suitable for incineration;As a backup site for emergency disposal of municipal solid waste.Therefore, landfill still plays a fundamental role and is indispensable for any city.In some areas, there is land available to be buried, but due to the “nimby effect”, people are not allowed to dispose of garbage next to their own homes, making it difficult to choose a site for sanitary landfill.
Composting is the most effective way to dispose of kitchen waste.In urban household garbage, kitchen garbage, non-recyclable garbage, recyclable garbage accounted for about 1/3.The recyclable garbage can be used comprehensively in all stages of recycling.If the separated kitchen waste can be recycled well, the amount of garbage can be cut in half.
Then, how to promote the classification and reduction of urban waste?The German approach, in the order of source reduction, recycling (including composting), incineration and recycling, and landfill treatment, stipulates that the next layer of technology can only be used if the first layer of technology cannot be used.
In view of the main disposal methods of municipal solid waste in China, the primary method of garbage classification is wet and dry separation.If the household kitchen waste is mixed with other household waste, it is easy to deteriorate, rot and breed bacteria, and becomes a pollution source in the process of garbage collection, transportation and terminal treatment.During landfill, mosquitoes and flies will breed and produce odor and leachate, while incineration will affect calorific value and produce dioxins.After the wet waste is separated, the leachate in the landfill can be reduced and the operating cost of sewage treatment in the landfill can be reduced.The total amount of waste decreased, which also extended the life of the landfill.For waste incineration plant, it not only reduces the treatment cost of leachate, but also optimizes the composition of incineration waste and improves the calorific value of waste.
From the point of view of waste end treatment, local governments should pay attention to the development of waste composting technology.Classification and collection is only the front-end of garbage disposal, and the effect of garbage classification is largely dependent on the back-end recycling, resource utilization and garbage disposal.From the whole waste treatment process, if the end of the treatment link is not, the front end of the classification will become a useless.At present, landfill or incineration is the main waste treatment method in large and medium-sized cities in China.In some cities and towns, there is only one way of garbage disposal: landfill. Since there is no garbage composting plant, the kitchen waste is recycled by private workshops and fed to pigs and fish, resulting in “garbage pigs” and “garbage fish”, or the use of swill to refine gutter oil.Therefore, it is an urgent issue to promote harmless composting of kitchen waste.
In addition, the local government should also seize the residents of garbage classification disposal this basic link.Adopt propaganda, supervision and reward to guide residents to do a good job in household garbage classification.The street organization community union own characteristic carries on the propaganda, guides the resident to classify consciously.At the same time, the community can establish a resident instructor supervision system.At present, some areas have tried to set up an instructor for every 50 households to supervise the classification of households that do not meet the requirements.The community supervised the resident instructors to check their attendance rate and sorting quality.The community rewards the residents who have done a good job in classifying, which can boost their enthusiasm.In addition, also want to play the main role of property company in garbage classification, property company can ask cleaners to do a good job in the second sorting and garbage bag work.