Types of waste Waste = any unwanted item or substance resulting from a human activity or process Municipal solid waste = from homes, institutions, small businesses Industrial solid waste = from production of consumer goods, mining, petroleum extraction, agriculture Hazardous waste = toxic, chemically reactive, flammable, or corrosive Wastewater = water used in homes, businesses, etc., and drained or flushed, plus runoff from streets

Why manage waste? Waste degrades water, soil, and air quality; does environmental and ecological harm. Waste does harm to human health. Waste is a symptom of inefficiency; wastes money. Waste is unpleasant aesthetically.

Ways to manage waste Three components of waste management: Source reduction, or reducing the amount of waste entering the waste stream, is best. Recovery (recycling and composting) is next best. Disposal is the least desired option.

Sources and Types of Solid Wastes MSW includes all the community waste with the exception of industrial process waste and agriculture wastes It is important to define the various types of solid wastes that are generated and the sources to design and operate of the functional elements associated with the management of solid waste

Sources and Types of Solid Wastes Typical facilities, activities, locations where wastes are generated Source Food wastes, paper, cardboard, plastics, textiles, leather, yard wastes, wood, glass, metals, ashes, special wastes (e.g., bulky items, consumer electronics, white goods, batteries, oil, tires), and household hazardous wastes Single and multifamily dwellings Residential Industrial process waste, scrap materials, etc. Non - industrial waste including food wastes, construction and demolition wastes, rubbish, ashes , hazardous wastes, ashes, special wastes Light and heavy manufacturing, fabrication, construction sites, power and chemical plants Industrial

(Cont’d) Types of solid wastes Typical facilities, activities, locations where wastes are generated Source Paper, cardboard, plastics, wood, food wastes, glass, metals, special wastes, hazardous wastes Stores, hotels, restaurants, markets, office buildings, etc. Commercial Same as commercial Schools, hospitals, prisons, government centers Institutional Wood, steel, concrete, dirt, etc. New construction sites, road repair, renovation sites, demolition of buildings, broken pavement Construction and Demolition

Typical facilities, activities, locations where wastes are generated (Cont’d) Types of solid wastes Typical facilities, activities, locations where wastes are generated Source Street sweepings; landscape and tree trimmings; general wastes from parks, beaches, and other recreational areas; sludge Street cleaning, landscaping, parks, beaches, other recreational areas, water and wastewater treatment plants Municipal Services (excluding treatment facilities) Spoiled food wastes, agricultural wastes, rubbish, hazardous waste. Field and row crops, orchards, vineyards, dairies, feedlots, farms, etc. Agricultural

Municipal solid waste Paper is the biggest component of municipal solid waste in the United States.

Nature of Municipal Solid Waste Organic (Combustible) Inorganic (non-combustible) Putrescible Recyclable Hazardous Infectious

Composition of Solid Wastes Composition is the term used to describe the individual components that make up a solid waste stream and their relative distribution Information on the composition of solid wastes is important in evaluating equipment needs, systems and management programme and plans

Composition of Solid Wastes The residential and commercial portion makes up about 50 to 75 percent of total MSW generated in a community The actual percentage distribution will depend on The extent of construction and demolition activities The extent of the municipal services provided The types of water and wastewater treatment process that are used

Typical Physical Composition of Residential MSW

Composition of Solid Waste The percentage distribution values for the components in MSW vary with Location Season economic conditions population Social behavior Climate Market for waste materials Other factor

Types of Materials Recovered from MSW Aluminum Paper Plastics Glass Ferrous Metals (Iron and Steel) Nonferrous waste Yard waste collected separately Construction and demolition wastes

Industrial solid waste Each year U.S. industries generate 7.6 billion tons of total waste. 97% of this is wastewater Industrial solid waste = roughly equivalent to amount of municipal solid waste Regulatory schemes are different: Federal government regulates municipal State or local government regulates industrial

Industrial solid waste Waste is generated at several points in the life cycle of products. At each stage there are opportunities for efficiency improvements, source reduction, and recycling.

Industrial ecology Involves modifying techniques of processing and manufacturing, and finding new uses for materials previously considered waste Seeks to redesign industrial systems to maximize: Physical efficiency AND Economic efficiency Tries to make sure all by-products produced are used, either in the same process or a different process

Hazardous waste Waste that poses a potential danger to human health Four criteria: • Ignitability: substances catch fire • Corrosivity: substances corrode metals • Reactivity: substances are chemically unstable and react with other chemicals in dangerous ways • Toxicity: substances are known to be harmful to human health

Hazardous waste There are many types of hazardous waste. Two are worst because they persist for a long time without breaking down: Heavy metals (mercury, lead, chromium, arsenic, cadmium, tin, copper — from industry, mining, consumer products) Organic compounds (synthetic pesticides, petroleum products, rubber, solvents, preservatives…)

Household hazardous waste We all have many hazardous substances in our homes and everyday lives. Many communities organize pickups or collection centers for this waste.

Radioactive waste Wastes that contain radioactive material A special type of hazardous waste Radioactive wastes are usually by-products of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research, medicine and military Radioactive waste typically comprises a number of radioisotopes: unstable configurations of elements that decay, emitting ionizing radiation which can be harmful to humans and the environment.