kitchen waste refers to the waste generated in the process of kitchen food processing and the biodegradable organic matter left on the table. In a broad sense, kitchen waste includes Restaurant kitchen waste and Household kitchen waste. The utilization ways of kitchen waste can be summarized into three categories: feed, fertilizer and fuel. For the kitchen waste that has not deteriorated, it should be used as feed, and for the kitchen waste that cannot be used as feed, it should be used as fertilizer first; The application ways of fertilization are aerobic composting and anaerobic digestion, which not only produces fertilizer, but also produces energy biogas; If the kitchen waste is mixed with impurities, the cost of fertilizer treatment is high, and it can only be disposed of in the garbage dump. Garbage disposal includes landfill treatment and incineration treatment. Under the condition of controlling the biodegradable organic matter to enter the landfill, it will enter the incineration plant for incineration treatment, that is, fuel treatment. It can be seen that the separate collection of biodegradable organic matter from kitchen waste is an important condition to realize high value! Of course, the leftovers that have not deteriorated can be used as feed, and the leftovers mixed with broken glass can neither be used as feed nor fertilizer, but can only enter the domestic garbage factory.

The management of kitchen waste in developed countries can give us beneficial enlightenment. For example, the United States implements classified management of kitchen waste, first of all, food donation, collecting excess food from schools, food stores, restaurants and factories and enterprises, and then donating it to places where food is needed. The Washington area and the state of Carolina have enacted a special act of giving good food, which stipulates that restaurants must be responsible for a certain amount of food donation. Secondly, livestock are raised by farms (breeding plants) or processed into animal feed in feed processing plants. Generally, pigs are the most common, but farmers who raise pigs must obtain permission from the Animal Health Committee before they can collect food waste, steam sterilize it and feed livestock. In addition, composting, many places have established special composting sites and perfect collection and composting systems to compost food waste that is not suitable for eating or food recycling. At present, most of the kitchen waste in American restaurants directly enters the domestic waste treatment plant after dehydration. Japan promulgated the Food Recycling Law in 2111, which clearly pointed out that wasting food is immoral and illegal. Call on the whole society to put an end to serious food waste. And it is stipulated that the inevitable food waste should be recycled and reused. This regulation can not only greatly reduce food waste in cities, but also provide safe fertilizer for agricultural production. In 2111, Japan began to implement the Food Waste Recycling Law, which stipulates that catering industries such as large supermarkets and restaurants have the obligation to recycle food waste and try to curb the generation of waste. According to the statistics of Japan's Ministry of Environment, the amount of household kitchen waste in 2117 was about 1.19 million tons, of which 94% was incinerated and landfilled with the waste. 8.27 million tons of food waste were produced by catering units and food processing units, of which 26% were used as feed, 23% as fertilizer, and 42% were incinerated and landfilled with the waste.

the choice of kitchen waste treatment mode depends on the level of economic development and the ability to control the source collection. The main ways of kitchen waste treatment (see Table 1) are: directly making feed (such as raising pigs), producing feed through drying, aerobic composting, anaerobic digestion (producing fertilizer and biogas), landfill treatment and incineration treatment. Each treatment cost and use conditions are different. If the source of kitchen waste collection cannot be controlled, the outlet of kitchen waste is suitable for garbage factory (field). If the source of kitchen waste collection can be controlled, and the kitchen waste can be given a higher subsidy, it is realistic and feasible to use kitchen waste for anaerobic digestion to produce fertilizer and biogas.