The harm caused by kitchen waste mainly includes the following aspects:

1. It affects the city appearance and living environment. In terms of sensory characteristics, kitchen waste is greasy and wet, which affects people's visual and olfactory comfort and life hygiene. High moisture content and organic components make it a "natural paradise" for microorganisms, and at the same time, it is more difficult to transport and treat garbage caused by high moisture content. In addition, the kitchen waste will increase the gas production and leachate precipitation in the landfill, which will pollute the surface and groundwater. 2. Feeding livestock as feed, also known as "swill pig". At present, it has become a traditional habit for farmers and farmers to eat kitchen waste (swill and swill) to raise livestock and poultry, especially pigs, in many provinces, cities and underdeveloped areas in China, which is a well-known reality. After careful analysis of swill, it is not difficult to find that all kinds of swill in the city come from thousands of households, all walks of life, different groups and individuals, and their composition is complex and varied. Some swill began to ferment, acidify, mold and even rot in spring and summer due to too long collection, storage and storage time. Some swill is often mixed with impurities and foreign bodies, such as gravel, wire, shells, bones, toothpicks and plastics, which can undoubtedly cause physical damage to the digestive tract of livestock and poultry. In particular, the kitchen waste discarded in all kinds of swill has been polluted by heavy metals such as aluminum, mercury and cadmium, as well as organic compounds and benzene compounds. After being eaten by pigs, harmful substances accumulate in pig fat, muscle and other tissues. When people eat such pork to a certain extent, the immune function of liver, kidney and other systems will decline. What's more, the harm of food waste is far from being recognized. Food waste in most cities in China is transported to suburban pig farms to raise swill pigs. Some units mistakenly think that the pork fed with food waste in their canteens is delicious and have no vigilance against its health hazards.

3. Harm caused by waste edible oil. Driven by huge profits, some unscrupulous traders recycle swill in the process of kitchen waste generation and extract oil by a series of means such as heating, filtering and distillation. Then use these so-called "gutter oil" and sell them to some small food outlets, restaurants and so on to make huge profits.

The extracted gutter oil will contain impurities, which will be contaminated with aflatoxin, benzene and other toxic substances. Long-term consumption will cause chronic diseases such as tumors, such as stomach tumors and liver tumors. If it is left unchecked, the waste cooking oil will undergo complex biochemical reactions in the water body, producing a series of malodorous substances such as aldehydes and acids. The odor of these malodorous substances will be emitted into the air, polluting the atmosphere and deteriorating the living environment, which will be strongly reflected by residents. Waste oil blocks the sewage pipeline, causing sewage to flow backwards; Waste oil pollutes groundwater, consumes oxygen in water body, causes eutrophication of water body and breeds mosquitoes, flies and other pests; Waste edible oil flows into rivers, which easily leads to suffocation of fish and shrimp due to lack of oxygen.