Cradle to Gate
Identity ID
d7a69588-eab3-4ef2-abca-411a583b0ecf
Waste treatment
Associated ID
e1e24ba5-3270-43f4-a5ad-862910ee1b92
Included activities starts
Included activities ends
Description
Composting technology has a simple process and convenient management, enabling local utilization of kitchen waste; however, due to its relatively small processing capacity, it is mainly applied in townships. An example is the shared greenhouse built jointly by several villages in Jindong District, Jinhua City (daily processing capacity of 1. 5 t/d), with compost maturation in about 30 days, achieving a compost output of 20% of the incoming waste. The greenhouse structure typically features an inclined transparent glass surface on the sun-facing side of the roof, effectively utilizing solar energy to accelerate composting. Inside the composting facility, both ventilation and heating pipe networks are installed to supply oxygen and heat to the materials piled within, promoting aerobic microbial metabolic activity and accelerating temperature rise and compost maturation.
Activity Description
Kitchen waste can be effectively converted into organic fertilizer through modern aerobic composting and mechanical composting technologies. This process typically includes three stages: pretreatment, microbial fermentation, and natural composting. In the pretreatment stage, the waste is sorted, shredded, and pressed to remove impurities and adjust moisture levels. Subsequently, the material undergoes high-temperature aerobic fermentation in a composting machine. Mechanical composting is an efficient and automated method for treating kitchen waste, enabling rapid transformation of kitchen waste through mechanical equipment. Finally, after a period of natural composting and maturation, the resulting fertilizer is of high quality, meets national organic fertilizer standards, and is suitable for agricultural and landscaping applications, achieving resource recovery and environmentally sound treatment of kitchen waste.
Process Description
kitchen waste on a dry basis: average organic matter content of 80–100%, crude protein 14–30%, and crude fat 15–30%; on a wet basis: moisture content 70–90%, oil content 3%, and salt content 1%.
Time period
2022
2026
Geography
China
Macroeconomic value
Business-as-Usual
Data validation
Yes
Technology
Current Technology
Technology comment
Aerobic composting. Aerobic composting is a process that, under aerobic conditions, utilizes aerobic microorganisms to decompose the organic matter in kitchen waste into soluble organic substances, which then enter microbial cells to participate in metabolism, ultimately forming humus fertilizer. The aerobic composting process generally consists of three stages: pretreatment, microbial fermentation composting, and post-treatment of the product. During the pretreatment stage, materials such as crop straw, sawdust, and rice husks are typically added to adjust the carbon-to-nitrogen ratio. Aerobic composting has advantages such as a simple process, low cost, and ease of operation, and it converts organic matter into organic fertilizer. Therefore, it is one of the mainstream technologies for kitchen waste treatment and utilization worldwide. However, composting requires a large land area and a long processing time, and the generated odors and leachate can cause environmental pollution. If kitchen waste contains excessive impurities, the quality of the compost will be poor, necessitating continuous improvements. Currently, composting technologies are trending toward miniaturization and specialization, leading to various methods primarily based on solar-powered composting and machine-assisted composting. Within solar composting sheds or machines, temperature and humidity can be better controlled to accelerate composting, while effectively managing secondary pollution such as wastewater and odors.