Food waste disposal

Kitchen waste, also known as restaurant kitchen waste, refers to food residues, food processing waste, expired food, waste cooking oil, etc. generated during eating activities. The goal of kitchen waste treatment is to achieve its reduction, harmlessness and resource utilization. The specific treatment methods include the following aspects: 1. Source reduction - Classification collection: Implement a kitchen waste classification system, separate kitchen waste from other waste, and facilitate subsequent treatment and resource utilization. - Food conservation: Advocate catering companies and individuals to reduce food waste, order meals reasonably, and pack leftovers to reduce the amount of kitchen waste from the source. 2. Pretreatment - Crushing and sorting: Use a crusher to crush kitchen waste to a certain particle size for subsequent treatment. At the same time, remove impurities such as metal, plastic, and glass through magnetic separation, wind separation, and screening. - Grease separation: Use an oil-water separator or centrifuge to separate the grease from kitchen waste, and the resulting waste grease can be further refined into biodiesel or used as an industrial grease raw material. 3. Biological treatment - Anaerobic digestion: In a closed container, anaerobic microorganisms are used to decompose organic matter in food waste under anaerobic conditions to produce biogas (which can be used as energy), biogas residue (which can be used as fertilizer or soil conditioner) and biogas liquid (which needs further treatment). - Aerobic composting: Under aerobic conditions, food waste is converted into stable humus and made into organic fertilizer through the biodegradation of microorganisms. Temperature, humidity, ventilation and other conditions need to be controlled during the composting process to ensure efficient and harmless conversion. 4. Biological transformation - Biological treatment such as black soldier flies and earthworms: Insects (such as black soldier fly larvae) or earthworms are used to ingest organic matter in food waste and convert it into insect protein, fat and insect feces. Insect feces are high-quality organic fertilizers, and insects can be used as feed raw materials or raw materials for biological products. 5. Thermochemical treatment - Incineration: Food waste is incinerated in a high-temperature incinerator, and organic matter is completely oxidized into carbon dioxide and water, and inorganic matter forms ash. The heat generated by incineration can be used for power generation or heating. Incineration must be equipped with tail gas treatment facilities to ensure that emissions meet standards. - Pyrolysis and gasification: Under anaerobic or anoxic conditions, pyrolysis of kitchen waste produces combustible gas, solid residue and a small amount of liquid products. Combustible gas can be used as energy, and solid residue can be used as fertilizer or building material raw materials. 6. Resource utilization - Grease recovery: The extracted waste grease can be further refined into biodiesel or as a chemical raw material. - Organic fertilizer production: Compost products, biogas residues, etc. can be used to improve soil and increase soil fertility. - Feed: Kitchen waste that has been strictly treated and meets food safety standards can be used as feed raw materials for animal husbandry. 7. End-of-life disposal - Landfill: For the part that cannot be utilized as a resource, after harmless treatment, it can be sent to a sanitary landfill for safe landfill if it meets landfill standards. - Safe disposal: For kitchen waste residues containing toxic and hazardous substances, special safe disposal is required, such as solidification/stabilization before landfill or sending to a special hazardous waste treatment facility. In summary, kitchen waste treatment is a comprehensive process covering source reduction, pretreatment, biological treatment, thermochemical treatment, resource utilization and terminal disposal. In actual operation, appropriate treatment methods and combinations should be selected in combination with local actual conditions, technical conditions and policy orientation to achieve kitchen waste reduction, harmlessness and resource utilization.