Based on different sources, kitchen waste is mainly divided into restaurant waste and food waste. The former is generated from restaurants, canteens and other catering industry leftovers, with a large amount of generation, the number of relatively concentrated, widely distributed characteristics, the latter mainly refers to the residents of the daily cooking waste scraps and leftovers from thousands of households, a huge number of relatively decentralized, the overall amount of more than catering waste.
A minute ago it was a delicacy, a minute later it became garbage. Because of its food culture and gathering habits, kitchen waste has become a uniquely Chinese phenomenon. China's table waste is staggering, producing huge amounts of kitchen waste every day. According to the statistics of relevant departments, the daily food and beverage waste (including waste edible oil and grease) is around 1,800-2,200 tons, and fluctuates with different seasons. The proportion of food waste in the physical group of domestic waste is generally around 50%, according to the 2015 domestic waste terminal processing capacity of 18,000 tons, if all food waste can be effectively separated out of wet and dry, then the theoretical amount of food waste will reach 0.9 million tons. Therefore, in order to achieve the classification and treatment of domestic waste, the ability to separate out food waste is very critical, so the wet and dry separation of residential households (i.e., low water content of other garbage and high water content of food waste) this link is particularly important.
Types of kitchen waste:
Rubbish classification
One is the garbage formed in the process of meal processing, mainly from vegetable cutting down the stems and leaves, vegetables entrained soil, fish scales, poultry head and feet feathers, etc., for the kitchen processing of the rest of the residue. This type of garbage does not contain leftovers and grease trap garbage, containing little oil, economic value is not high, generally no one to collect such garbage alone, this type of garbage is mostly used for composting, the production of organic fertilizers;
The second is the leftovers of the leftovers of food, commonly known as slop. This type of waste is mainly leftover meals and soups, etc., from which the oil proposed is called slop oil. This kind of oil is basically neutral in nature, the acid value is not high, it is easy to enter the cooking oil. Such pigs grown on swill are called garbage pigs.
Third is grease trap garbage. This kind of garbage is mainly restaurants in the process of scrubbing, tableware in the remaining small amount of meals and some grease, detergent with the scrubbing water into the grease trap, grease substances floating on the water surface, the formation of grease trap garbage. The grease content of grease trap waste is relatively high, generally 20% - 80%. With the different levels of restaurants, the oil content varies greatly, and the oil extracted from the grease trap is called "gutter oil", which has a higher freezing point and a higher acid value.
The hazards of unclassified kitchen waste:
Because kitchen waste is highly susceptible to rotting and deterioration, it can produce unacceptable bad feelings, such as irritating odors. The kitchen waste generated by the catering industry has a large content of leftover vegetable soup and rancid water, which is easy to leak during collection and transportation, affecting the urban environment. Kitchen waste is directly disposed of in landfills, which can cause serious pollution of groundwater.
According to the Ministry of Agriculture experts, kitchen waste contains a large number of nutrients, the main components are fats and proteins, kitchen waste can be replaced by corn, fishmeal, soybean meal, etc. processed into high-energy protein high-quality feed, but also the production of biodiesel is a suitable raw material.
Experts explained that, according to the dry matter content, 50 million tons of kitchen waste is equivalent to 5 million tons of high-quality feed, containing energy equivalent to 10 million acres of arable land each year, the amount of energy output, the amount of protein equivalent to 20 million acres of soybean each year, the amount of protein output. That is to say, if China's annual output of kitchen waste can be fully utilized, equivalent to saving 10 million acres of arable land.