Whether it is mixed domestic waste or classified waste, the composition of the material is an important basis for process design. The composition of the material is affected by factors such as time, season, regional culture, and economic development, and is highly random, making it difficult to improve the homology of the waste material through human intervention.
Through years of research and design of treatment processes, it is found that the design of solid waste treatment processes directly affects the operating cost of the corresponding production line, and the production line can be optimized in a targeted manner by artificially controlling design factors (including treatment volume, end material output, use or potential market value, etc.). Taking the treatment ideas of plastic waste in mixed domestic waste treatment processes and recyclable waste processes as an example, when recyclable plastics are in mixed domestic waste, they are soaked in garbage leachate or adhered to organic matter. If they need to be recycled, the design of screening, washing, purification and other processes will lead to increased resource recovery costs. A more optimized design is to directly sort them and then incinerate them in the furnace; when recyclable plastics are present in recyclable waste, the design of direct photoelectric sorting can greatly reduce the resource recovery cost.
The process design of waste treatment requires the designer and the owner to conduct a preliminary investigation on the following information: (1) the properties of waste materials (material composition, moisture content, etc.). (2) process ideas (selection of resource-based, fuel-based or mixed routes). (3) the potential market for resource-based or fuel-based materials (the types of resource-based or fuel-based materials and the potential market value increase of various resource-based materials need to be analyzed in combination with the local market). Only after both parties have a comprehensive understanding of this information and reach a consensus can the design of the process flow be rationalized, practical and economical.
From the perspective of the development of the solid waste industry, due to the lack of back-end classification and processing technology and facilities, most regions are currently unable to achieve the integrated management and operation of "front-end classification collection and transportation" and "end classification disposal". Relevant governments need to encourage the application of new and efficient technologies through policies to fill the gaps. In order to realize the complete classified garbage disposal model of "resident classified disposal", "front-end classified collection and transportation", "mid-end classified treatment" and "end classified disposal" in the era of solid waste industry 3.0, the government also needs to help promote the construction of classified garbage disposal industrial park model, coordinate various types of garbage disposal, and improve the collaborative processing capacity of existing facilities to fill the gaps in technology and facility support at the "front end" and "end", and finally achieve the goal of rational incineration and harmless landfill.
At present, the level of domestic garbage treatment plants varies. Before the 3.0 era, many garbage production lines in my country were completed by "copying" foreign advanced equipment or technology; the 3.0 era strongly advocates the development of garbage classification and treatment work suitable for Chinese characteristics. Therefore, solid waste industry practitioners should focus on the research and development of distinctive garbage treatment processes and production lines, pay attention to technological innovation, focus on the social output of ecological value, and try to get rid of or reduce dependence on imported and foreign technologies.
