Unit 8: Solid and Hazardous Waste Management

Municipal Solid Waste (MSW)

Refuse collected by municipalities from households, small businesses, and institutions, commonly known as 'trash' or 'garbage.'

Sanitary Landfill

An engineered system designed to isolate waste from the environment, unlike open dumps.

Leachate

The liquid that passes through compacted solid waste, containing toxic chemicals and heavy metals.

Methane

A potent greenhouse gas ($CH_4$) produced during anaerobic decomposition of waste in landfills.

Anaerobic Decomposition

Decomposition that occurs without oxygen, which produces methane in landfills.

Cap / Soil Cover

A layer of clay/soil/vegetation covering a landfill at the end of its operation to reduce pests and odors.

Waste-to-Energy

A method of incineration that produces electricity from the heat generated by burning waste.

Particulate Matter (PM)

Air pollutants released during incineration that need to be filtered.

Ocean Dumping Act

A law prohibiting ocean dumping to protect marine environments and wildlife.

Three Rs of Waste Management

Reduce, Reuse, and Recycle; a hierarchy guiding waste management priorities.

Composting

The controlled biological decomposition of organic matter under aerobic conditions.

Hazardous Waste

Material harmful to human health or the environment, such as ignitable or toxic waste.

E-Waste

Discarded electronic devices like TVs and computers, often containing harmful heavy metals.

RCRA (Resource Conservation and Recovery Act)

A law governing the disposal of solid and hazardous waste with a 'Cradle-to-Grave' approach.

CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act)

Also known as the Superfund Act, it funds the cleanup of abandoned hazardous waste sites.

Primary Treatment

The physical process in sewage treatment to remove large solids from wastewater.

Secondary Treatment

The biological treatment process to reduce organic matter in wastewater using aerobic bacteria.

Tertiary Treatment

The advanced treatment phase that removes inorganic nutrients from wastewater to prevent eutrophication.

Sewage Sludge

The solid material remaining after wastewater treatment that can be disposed of or used as fertilizer.

Septic Systems

Wastewater treatment systems used in rural areas where wastewater flows into a tank and then a leach field.

NIMBY (Not In My Backyard)

A term describing the attitude that leads to difficulties in siting waste disposal facilities.

Closed-loop recycling

The process of turning a product into the same product, such as aluminum cans into new aluminum cans.

Open-loop recycling

The process of turning a product into a different product, such as plastic bottles into fleece jackets.

Leachate Collection System

Pipes at the bottom of a landfill that collect toxic leachate for treatment.

Bottom Ash

The toxic residue produced from incineration that must be disposed of in hazardous waste landfills.

Grit Chambers

Settling tanks in primary treatment that allow heavy grit and sand to sink and be removed.

BOD (Biological Oxygen Demand)

A measure of organic matter in water, which is reduced during secondary treatment.