Based on the source of waste, solid waste is divided into domestic waste, industrial solid waste and agricultural solid waste. Domestic waste refers to solid waste generated in daily life or activities that provide services for daily life, as well as laws and administrative regulations provide that solid waste is considered as domestic garbage, including urban domestic waste and rural domestic waste, consisting of daily life garbage and cleaning garbage, commercial garbage, medical service garbage, urban sewage treatment plant sludge, cultural and recreational garbage, etc., to provide services for the life of commercial or business garbage; industrial solid waste is the source of solid waste, industrial solid waste is divided into agricultural solid waste. business; industrial solid waste refers to solid waste generated from industrial production activities (including scientific research), including industrial waste, waste chips, sludge, tailings and other wastes; agricultural solid waste refers to solid waste generated from agricultural production activities (including scientific research), including wastes generated from five types of agricultural industries: planting, forestry, animal husbandry, fishery, and sideline industries. If solid waste generated by services, industry and agriculture are collectively referred to as industrial waste, solid waste can be broadly categorized into 2 major groups: daily life waste and industrial solid waste (including solid waste generated by industry-related undertakings). The sources of solid waste and their classification are given in Table 1.1 .

Table 1.1 Sources of Solid Waste and Their Classification Land Use Functional Areas Sources of Waste Classification of Waste Composition Residential Areas Various Types of Houses and Apartments Domestic Waste Daily Waste Kitchen Waste, Packaging Waste, Dung Scum, Ash, Green Waste, Special Wastes Outdoor Open Spaces, Waters Highways, Streets, Sidewalks, Lanes and Alleys, Parks, Playgrounds and Seaside Janitorial Waste Sweeping Gatherings ( Leaves, branches, dirt, mud, animal carcasses, water flora), green waste, special waste Commercial areas Shops, restaurants, markets, offices, hotels, printing presses, garages, hospitals, institutions Commercial waste Kitchen waste, packaging waste, animal carcasses, ashes, construction waste, green waste, special waste Water or sewage treatment plants Water purification plants, sewage plants Municipal waste Sludge Industrial areas Building creation or demolition, Various types of industries, mining plants, thermal power plants Industrial waste Construction waste, slag, waste debris, waste plastics, waste chemicals, sludge, tailings, packaging waste, green waste, special waste Agricultural areas Fields, farms, forests, livestock farms, dairy farms, pastures Agricultural waste Agricultural waste, crop waste, manure sludge, animal carcasses, green waste, special waste Rural areas Residential areas, Agricultural areas Residential areas, agricultural areas, outdoor open spaces, waste disposal sites, a few industrial or commercial Rural waste All of the above Urban areas Residential areas, commercial areas, industrial areas, outdoor open spaces, waste disposal sites, a few agricultural Urban waste All of the above Note: Special waste includes large furniture and home appliances and hazardous, poisonous, and dangerous wastes that are incendiary, explosive, radioactive, chemically reactive, and pathogenic.

Table 1.1 lists rural waste and urban waste. Differences in economic and social development between urban and rural areas cause differences in the composition and nature of urban and rural waste. Urban solid waste is mainly composed of industrial waste, and the output of industrial waste is about 6 to 8 times of the output of daily life garbage; rural solid waste is mainly composed of agricultural waste, especially crop waste (including decayed agricultural products), followed by agricultural garbage and domestic garbage.

Solid waste is categorized in many ways, in addition to the above classification, but also according to the nature of the waste, form or treatment methods. According to the nature of solid waste can be divided into organic and inorganic; according to the hazardous, can be divided into general waste and hazardous waste; according to the form, can be divided into solid (block, granular, powder) and mud waste; according to the method of waste treatment can be divided into combustible and non-combustible, and so on.

In order to facilitate the diversion of solid waste disposal, combined with China's customary understanding of waste classification and collection and transportation, this book will be divided into 14 categories of solid waste: domestic garbage, kitchen waste, bulky waste, construction waste, urban sewage treatment plant sludge, green waste, fecal sludge, animal carcasses, medical waste, e-waste, waste vehicles, industrial waste, agricultural waste, hazardous waste, Table 1.2 gives its composition and sources. Because the 14 categories of waste originate from different classification methods, their connotations and extents differ from those of the waste of the same name in Table 1.1. Where the classification is not explicitly stated, the main components of the various types of waste are specified in Table 1.2.

Table 1.2 Solid Waste Types, Composition and Their Sources Waste Types Main Composition Sources Domestic Waste Paper scraps, wood scraps, waste plastics, fee leather, packaging waste, ash and other general waste Households, restaurants, markets, canteens, hotels, institutions, schools, stores Cleaning Waste Outdoor open space, waters Kitchen Waste Kitchen waste (preparation, cooking and meal after the waste, vegetable market organic waste) Households, farmers' markets and markets. Food waste (waste after preparation, cooking and meals, organic waste from vegetable markets) Households, farmers' markets and supermarkets Food waste (slop, leftovers, etc.) Catering industry, non-profit canteens on a large scale Food waste (expired food, spoiled food, etc., from the process of storing, processing, selling, and consuming food) Enterprises that deal with food and its semi-finished products, households, the catering industry, and non-profit canteens on a large scale Bulky garbage Bulky furniture and electrical appliances Households, restaurants, markets, cafeterias, institutions, schools and stores Construction waste Construction demolition materials (lumber, steel, concrete mix, bricks, stones, undercutting soil, and others from demolition of buildings or projects), camping waste (lumber, steel, and other camping waste) Demolition and construction sites, new construction, renovation Town and city water and wastewater treatment plant sludge Screening materials, sinking sand, flotsam, and sludge Water purification plants, wastewater treatment plants Greenwaste Branches, leaves, flowers, and grass Residential areas, commercial areas, outdoor open space, and water areas, Industrial areas, agricultural areas Faecal sludge Manure and its residues Manure pits, septic tanks Animal carcasses Carcasses of chickens, ducks, cats, dogs, pigs, cows, sheep, horses, etc. Households, farms, outdoor open spaces, waters Medical waste Waste syringes, wound dressings, blood-bearing waste Hospitals, outpatient clinics, scientific research institutes Electronic waste Refrigerators, air conditioners, washing machines, televisions, computers, cell phones, waste electronic components Households, restaurants, markets, stores, Schools, institutions, electronic and electrical factories Waste vehicles Motor vehicles such as cars, pedal cars Households, enterprises and institutions Industrial waste Waste slag, waste chips, waste plastics, waste chemicals, sludge, tailings, packaging waste Various types of industries, mining factories, thermal power plants Agricultural waste Agricultural waste, crop waste Fields, farms, forests, livestock farms, dairy farms, pastures Hazardous waste Flammable, explosive, chemical reaction, chemical reaction, toxic waste, Radioactive, explosive, chemically reactive, pathogenic waste Households, hospitals, hotels, factories, stores, scientific research institutions Organic and inorganic wastes can be divided into organic wastes and inorganic wastes according to their compositions; hazardous wastes and general wastes according to their polluting characteristics. In the Solid Waste Pollution Prevention and Control Law, it is divided into municipal solid waste, industrial solid waste and hazardous waste.

Solid waste is usually divided into municipal solid waste, industrial solid waste and agricultural waste according to its source. Municipal solid waste Municipal solid waste mainly refers to solid waste generated in daily life in the city or in activities providing services for daily life in the city, i.e., municipal garbage, which mainly includes residential garbage, hospital garbage, commercial garbage, and construction garbage (also known as sludge). Generally speaking, the amount of garbage per person per day in the city is 1-2 kilograms, the amount and composition of which are related to the residents' material living standards, habits, the degree of recycling of waste materials, municipal buildings, and so on. For example, domestic garbage is mainly kitchen garbage. Some of the municipal solid waste is very alarming in terms of the annual production of municipal solid waste. In the middle of the 18th century, only 3% of the world's population lived in cities; by 1950, the proportion of urban population was 29%; in 1985, this figure rose to 41%. By 2025, it is expected that 60% of the world's population will live in or around cities. With so many people living or about to live in cities, which are highly concentrated areas where the environment is greatly artificial, the pollution generated by municipal waste is extremely prominent.1980 Disposal of Municipal Waste by CountryCountry

Number of Municipal Wastes Disposed of (Tons) United States160*106Japan43.9*106Germany32.6*106Britain16.0*106France 15.5*106Italy14.0*106Canada12.6*106

From the table, it can be seen that, in general, the higher the standard of living in the city, the higher the amount of garbage generated, and in the big cities of low-income countries, such as Kolkata, Karachi, and Jakarta, the amount of garbage generated per person per day is 0.5-0.8 kilograms, and in the big cities of industrialized countries, the amount of waste generated per person per day is usually around 1 kilogram.

Industrial solid waste

Industrial solid waste refers to solid wastes such as mining waste rock, beneficiation tailings, fuel slag, chemical production and smelting slag, etc., also known as industrial waste or industrial garbage, which are generated during industrial, transportation and other production activities. Industrial solid waste can be roughly divided into six categories according to its source and physical properties. And according to the toxicity of the waste can be divided into two categories of toxic and non-toxic waste, where fluorine, mercury, arsenic, chromium, lead, cyanide and its compounds and phenol, radioactive substances are toxic waste.

Agricultural waste

Also known as agricultural waste, mainly from feces and plant stalks.