With the development of economy, the pace of urbanization in China is accelerating, people's living standards are improving day by day, and urban environmental problems are gradually concerned by people. At present, the treatment of municipal solid waste has become one of the key factors of urban environmental problems. With the growth of population, there will be more and more municipal solid waste. How to deal with municipal solid waste is not only directly related to a city's environmental problems, but also represents a city's development level. Only by reasonable planning and disposal of municipal solid waste can we really improve the urban environment and realize the sustainable development of the economy.
Keywords: urban garbage disposal; Environmental problems; Processing strategy; Garbage disposal site
First, the current problems in the construction of urban waste projects in China
With the development of economy, environmental problems are becoming more and more serious, and urban garbage has become one of the biggest problems threatening urban environment in modern urban management. The traditional way of urban garbage disposal is landfill, but there are still great hidden dangers in this way. The main problems are as follows: 1, landfill needs to occupy a lot of land. With the development of the city, a lot of farmland has been developed for building houses, factories and street development. Less and less agricultural land is becoming more precious. However, landfill will occupy more land. As we all know, it takes at least 100 years for plastic waste to be completely decomposed. During this period, no crops can be planted in the landfill area or even around it. Moreover, people can't live for at least decades, which can be said to be a huge waste of land resources. However, if these rubbish can be used, or used to make energy, etc. The economic value will be immeasurable. 2. Sanitary landfill will still pose a threat to the environment and people's daily life. In fact, there are great risks in disposing of garbage by sanitary landfill. Sanitary landfill requires high technical level. If the garbage disposal does not meet the requirements, the following problems may occur. First, garbage will produce a lot of combustible gas in the process of being decomposed by microorganisms, which is likely to explode under the action of underground high pressure; Secondly, in the process of landfill, people will add some substances that are helpful to the degradation of garbage. Once these substances flow into the ground, they will pollute the groundwater and even threaten people's health. Third, some recyclable garbage has also been landfilled, which has caused great waste of resources; Fourthly, the waste gas produced by landfill will not only make the surrounding air stink, but even threaten the life and health of people around. 3. The composition of municipal solid waste is complex, which is influenced by economic development level, energy structure, natural conditions, traditional habits and other factors, so the treatment of municipal solid waste abroad is generally different from the national conditions, and it is difficult to have a unified model because different regions of a country often adopt different treatment methods. However, in the end, they all aim at harmlessness, resource utilization and reduction. Most countries in the world generally give priority to sanitary landfill], and incineration technology is limited by the production of carcinogens such as dioxins. At present, the management and technology of urban garbage collection, transportation and treatment in developed countries are very mature and have accumulated a lot of experience. In terms of collection, most countries have adopted classified collection; In terms of transportation, closed compression transportation is basically adopted.
Second, do a good job in the construction strategy of the garbage disposal site project
(a) the choice of landfill must be reasonable. For the sake of environmental protection, our country has clear regulations on the area of landfill, and the specific places that are strictly forbidden to be used as landfill are stipulated in our laws in detail, and some areas can never be used as landfill. First of all, the gathering place of drinking water resources cannot be used as a landfill. It goes without saying that if drinking water resources are polluted, it is not only an environmental problem, but also a threat to people's lives and property. Secondly, the flooded area can't be used as a landfill, because it is likely to be washed away by floods in high flood season, and the pollution to the environment is immeasurable. Areas with underground mineral deposits cannot be used as landfills. If underground mineral deposits are to be mined in Suifeng Qufu Environmental Sanitation Administration at 273 100 in Qufu, Shandong Province, the landfill will be relocated. Isn't this unnecessary? Then the nature reserve is not allowed to be used as a landfill, and the nature reserve must maintain its most primitive ecological appearance, so it cannot destroy its ecological environment. Finally, parks, cultural relics protection areas and scenic tourist areas cannot be used as garbage disposal plants. 2. Requirements of landfill for environmental and geographical conditions. The choice of landfill is generally plain area, valley or sloping land, and these areas are all areas with small infiltration without exception. Because landfill leachate is undoubtedly the most harmful problem to the environment in sanitary landfill waste treatment methods. Therefore, when choosing a garbage disposal site, we should first consider the geographical conditions, followed by environmental protection, and finally the convenience of transportation, how far it is from the city, whether it is suitable to build a garbage disposal plant, and so on. If leachate seeps out unexpectedly during garbage disposal, we should be able to come up with a rescue strategy in time.
(2) How to treat leachate. 1. Physical and chemical methods. The physical methods that can be used mainly include filtration, adsorption and precipitation, and the chemical methods mainly include oxidation and reduction. These methods can not only control the leakage of leachate, but also purify leachate and make it a natural water resource again. Among them, the catalyst produced by modern science and technology not only has good effect but also has low cost, which greatly improves the effect of harmless treatment of leachate. 2. Selection of leachate treatment process. There are many kinds of leachate treatment processes in China, such as the traditional anaerobic-aerobic framework, as well as the physicochemical means of efficient air flotation and ammonia stripping as auxiliary means of biochemical treatment; There are MBR membrane bioreactor, UF ultrafiltration, pure oxygen aeration and other processes. Each process has its own advantages and disadvantages. At present, there is no mature treatment process suitable for China's national conditions to be popularized. The leachate treatment process of each landfill site is constantly explored and improved under its own conditions and environment.
(3) Soil improvement and ecological restoration of landfill. 1. Soil improvement of garbage dump. The reclamation project of landfill is a key link to use the fertility of new soil artificially added to restore the productivity of crops and realize the agricultural reuse of landfill. The main contents of reclamation engineering technology are soil improvement, vegetation species selection, soil erosion control and slope stability of garbage dam (or auxiliary dam). Soil improvement is mainly to increase soil organic matter content and improve physical and chemical properties through green manure or organic manure. 2. Vegetation restoration of garbage dump. Trees with strong resistance and good air purification ability should be selected around areas with high pollutant concentration such as treatment stations and biogas treatment facilities. Tree species with tall and beautiful trees, rapid growth, easy management and certain pollution absorption capacity are selected on both sides of the road. Trees or shrubs with beautiful trees and ornamental value can be selected in the administrative welfare area, and some monitoring plants with weak resistance and strong sensitivity can be cultivated at the same time. In order to prevent soil erosion, isolation belts, slope protection forests and ditch protection forests can be built to store water and protect soil, reduce surface runoff and sediment flow into landfills, minimize or avoid adverse effects on the surrounding environment during landfill, improve the environmental quality of landfills, improve the land properties after landfill, and increase urban greening in a planned way.
Three. Concluding remarks
With the acceleration of urbanization, the output of municipal solid waste will also increase. Only by properly handling municipal solid waste can we really improve the urban environment and realize the sustainable development of economy, so the treatment of municipal solid waste is directly related to the future urban environment.
References:
[1] Li Rongbin. Analysis on the Harm and Treatment of Domestic Waste [J]. Science and Technology Information, 20 14(08).
[2] worry. History and future of garbage [J]. Qinghai Science and Technology, 20 15(06).
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