In view of the current situation of complex and variable composition of municipal solid waste, high moisture content, and excessive proportion of organic waste, from the perspective of comprehensive treatment, choosing a reasonable municipal solid waste pretreatment process route can improve its effect and efficiency, and reduce operating costs.
1. Application of traditional kitchen waste management
Traditional kitchen waste management is a necessary front-end treatment process for incineration and composting processes. It uses magnetic separation, sorting and crushing of garbage to meet the process requirements of subsequent treatment. For incineration, most of the non-combustible components such as slag and dirt in the garbage are removed through garbage pre-treatment methods such as hand selection, magnetic separation, mechanical screening, flotation and photoelectric sorting, and the calorific value of the garbage is increased to 6000kJ/kg, thereby improving the combustion stability and daily processing capacity of the waste incinerator, reducing the pressure on exhaust gas treatment, reducing the consumption of auxiliary fuel and incineration treatment costs, thereby improving power generation efficiency.
For the garbage composting system, through mechanical screening, winnowing and other means of garbage, non-composable materials such as metal, plastic, glass, dust and large stones can be separated. This not only greatly increases the content of organic matter in the garbage, but also reduces the pollution of heavy metals in the garbage such as waste batteries, minimizing the harm of composting.
2.Application of mechanical biological kitchen waste management
Mechanical biological kitchen waste management is a model for the application of modern biotechnology in waste treatment. During the application of this technology, materials such as metal and glass in garbage can be recycled, and high-heat-mass materials such as plastics are used for incineration to generate electricity and heating. Therefore, this technology can play a big role in the reduction, resource utilization and harmless treatment of garbage.
Practical research has proved that after mixed garbage is mechanically and biologically treated, 95% of degradable TOC (total organic carbon) and 86% of non-fiber carbohydrates are converted, the weight, volume and moisture content of the garbage will be reduced, and the calorific value will be increased. It facilitates subsequent processing and reduces the impact on the environment. The application of biological pretreatment technology in domestic waste treatment will help improve incineration efficiency, extend the service life of landfills, and reduce the difficulty of leachate treatment. Its comprehensive economic indicators are better than traditional waste treatment solutions without pretreatment.
3.Application of biomass kitchen waste management
Since traditional sanitary landfill, incineration and composting treatment methods have certain drawbacks, anaerobic digestion has been widely used as an ideal waste treatment method in recent years. However, the properties of materials have a great influence on the anaerobic digestion process. Under the same treatment process and conditions, the results of anaerobic digestion treatment of garbage of different properties are quite different. Therefore, how to pretreat domestic waste, balance its physical and chemical properties, and optimize the anaerobic digestion process have become problems that must be solved in the application of anaerobic digestion treatment technology for domestic waste.
Biomass kitchen waste management technology is applied to the anaerobic digestion treatment process of garbage, which can improve the physical and chemical properties of organic matter, improve the degradation of refractory organic matter by microorganisms, and optimize the anaerobic digestion process of garbage, thereby achieving comprehensive utilization and turning waste into treasure, which is relatively It can effectively realize the purpose of resource utilization, reduction and harmlessness of urban domestic waste treatment.
Biomass kitchen waste pretreatment equipment mainly includes feeding, crushing, sorting, and depackaging systems. The process flow is as follows:
- Kitchen Waste is transported to a large garbage transfer station, and the garbage is poured into the garbage receiving hopper at the designated location. The lower part of the garbage receiving hopper is connected to a flat-plate feeding device. The flat-plate feeding device transports the garbage to the crushing equipment for coarse crushing.
- The crushed garbage continues to be transported by the screw conveyor to the sorting machine for preliminary screening, and then enters the biomass separation device through the screw feeder. Biomass separators and sorters have three functions: first, to break large particles into pulp; second, to separate light substances such as plastic bags, paper, etc. from the slurry; third, to remove some metals, stones, and glass. Substances can also be effectively separated from slurries by this device.
- The separated slurry is mainly organic matter. The bottom of the depackaging machine is transported to a storage tank through a pipeline for temporary storage. The separated organic matter is then input into a tanker through a soft connection and transported to the anaerobic digestion treatment system. Plastic bags, paper, bamboo, metal, stones, glass and other components are transported to inorganic waste storage tanks by conveying devices, and are then transported by garbage trucks for recycling or landfill.
Due to the complex and variable composition of kitchen waste, high moisture content, and excessive proportion of organic waste, a single waste treatment method is costly and difficult to meet the requirements of resource utilization, harmlessness, and reduction. In most cities, Classified collection of domestic waste is not achievable in the short term. Therefore, combining pretreatment technology and equipment with incineration and landfill or biological treatment processes has become an ideal way to deal with kitchen waste.