Types of waste

• 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

Waste = any unwanted item or substance resulting from a human activity or process

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 wasteThree components of waste management:

1. Source reduction, or reducing the amount of waste entering the waste stream, is best.

2. Recovery (recycling and composting) is next best.

3. Disposal is the least desired option.

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

Source Typical facilities, activities, locations where

wastes are generated

Types of solid wastes

Residential Single and multifamily dwellings

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

Industrial Light and heavy manufacturing, fabrication, construction sites, power and chemical plants

Industrial process waste, scrap materials, etc. Non - industrial waste including food wastes, construction and demolition wastes, rubbish, ashes , hazardous wastes, ashes, special wastes

(Cont’d)

Source Typical facilities, activities, locations where wastes are generated

Types of solid wastes

Commercial Stores, hotels, restaurants, markets, office buildings, etc.

Paper, cardboard, plastics, wood, food wastes, glass, metals, special wastes, hazardous wastes

Institutional Schools, hospitals, prisons, government centers

Same as commercial

Construction and Demolition New construction sites, road repair, renovation sites, demolition of buildings, broken pavement

Wood, steel, concrete, dirt, etc.

(Cont’d)

Source Typical facilities, activities, locations where wastes are

generated

Types of solid wastes

Municipal Services (excluding treatment facilities)

Street cleaning, landscaping, parks, beaches, other recreational areas, water and wastewater treatment plants

Street sweepings; landscape and tree trimmings; general wastes from parks, beaches, and other recreational areas; sludge

Agricultural Field and row crops, orchards, vineyards, dairies, feedlots, farms, etc.

Spoiled food wastes, agricultural wastes, rubbish, hazardous waste.

Municipal solid wastePaper 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

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 WasteThe 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 efficiencyAND

Economic efficiency

• Tries to make sure all by-products produced are used, either in the same process or a different process

Hazardous wasteWaste 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.