Solid waste treatment is the process of reducing its size and accelerating its natural purification by physical means (e.g., crushing, compression, drying, evaporation, incineration, etc.) or by biochemical action (e.g., oxidation, digestion and decomposition, absorption, etc.) and chemical action such as pyrolysis and gasification. It also usually refers to solid and sludgy materials discarded by human beings during production and living activities, including solid particles separated from wastewater and exhaust gases. However, no matter what treatment method is used, there is still a certain amount of solid waste remaining in the end, which needs to be disposed of properly. In particular, secondary pollution should be avoided and toxic and hazardous wastes should be disposed of in such a way as to ensure that they are not harmful to human beings. It is essential to develop a comprehensive and integrated treatment plan for solid wastes generated in cities. The purpose of integrated treatment is to concentrate all kinds of wastes in the city to a certain place, and according to the characteristics of solid wastes, to combine all kinds of waste treatment processes into a system, so that the material and energy obtained from each process can be rationally and centrally utilized. Through comprehensive treatment can be effective disposal of waste, reduce final waste emissions, reduce environmental pollution in the region, to prevent the spread of secondary pollution, but also to achieve low total treatment costs and high efficiency of resource utilization.

Solid Waste Generation Pathway and Classification

Social Material Flow and Solid Waste Generation Pathway, the material to maintain all the activities of human society, are in a state of dynamic equilibrium and follow the law of conservation of mass, can be used to describe the law of social material flow shown in Figure 9-1. Analyze the flow chart, you can get two revelations: ① all human activities relative to the external environment, is only the development and use of natural resources, and ultimately the resources in the form of waste equal amount of return to the environment. This "utilization and return" of resources is often in a state of flux. In the production and consumption of products, are produced in various forms of waste, part of these wastes in the production and consumption of recycling and reuse, but it happens to be the same amount of raw materials developed in the environment, in the form of waste back to the natural environment, forming a closed loop system. ② In modern society, every aspect of human activity produces waste in various states, from the development of raw materials in the environment to the utilization of products. The only way to reduce the production of waste is to reduce the consumption of raw materials per unit of product and reduce the development of raw materials. Solid waste is an integral part of the social logistics system and follows the above laws.

Solid waste is categorized on the basis of the pathway and nature of its generation. In economically developed countries, solid waste is divided into industrial waste, mining waste, agricultural waste and municipal garbage four categories. China's development of the "solid waste management law", solid waste is divided into, factory solid waste (slag) and municipal garbage two categories. Containing toxic and hazardous components of industrial solid waste, because of its special hazards to the environment and human beings, separate out a "hazardous waste" subcategory.