Waste

The Generation of Waste

• The US generates more than 10 billion metric tons of solid waste each year!

• Solid Waste – any discarded solid materials– Junk mail, paper waste, cardboard– Food waste– Cans, bottles, plastics– Diapers, clothing– Packaging, containers, wrappers– Appliances, cars

Not All Wastes Are Equal

Biodegradable Nonbiodegradable

Ex: plant & animal waste, newspaper,

paper bags, cotton fiber, leather

Ex: polyester, plastic, glass, metal

A material that can be broken down by biological processes (decomposers).

A material that cannot be broken down by biological processes.

Municipal Solid Waste

• Wastes produced by households and businesses (AKA – waste made by all of us). Over 236 million tons of all US waste comes from municipal solid waste.

Solid Waste from Manufacturing, Mining, and Agriculture

• These make up most of the rest of the total solid waste produced in the US.

• Includes: scrap metal, plastics, paper, sludge, ash, leftover rock, crop waste, & manure.

** Are average people responsible for this waste?

Where does your trash go when you throw it away?

Think Pair Share

Landfills• A permanent waste-disposal facility

• Wastes are put in the ground • Wastes are covered each day with a layer of soil,

plastic, or both.

Landfill Problems1.Leachate – water that

passes through the solid waste in a landfill, collecting dissolved chemicals from decomposing garbage.

Env.Prob. = leachate could flow into groundwater supplies & make drinking water unsafe to drink

Solution – monitoring wells & storage tanks that hold and treat waste water.

Landfill Problems

2. Methane Gas – flammable gas produced by decomposing organic (once living) waste.

Env.Prob. = methane could seep into the ground & into basements of homes up to 300m away; which could be ignited and/or explode.

Solution – pumped out of landfill & used as fuel.

Landfills Now & Later• New landfills are required to have safeguards that

reduce pollution problems.– Lined with clay & plastic– Leachate collection & treatment systems– Vent pipes for methane

• We are running out of space for landfills

Think Pair Share

• Imagine that all of the landfills are full and that no more land is available to build new landfills.

– What would people do with their wastes?– How might this impact the environment?– How might this impact our society

(economics, politics, etc.)

Incinerators• In 1999, the US had 102 operational incinerators that

were capable of burning up to 94,000 metric tons of municipal solid waste per day.

• But,– Some of the waste should not be incinerated (paint,

cleaners, batteries, etc.)– Incinerated trash becomes ash that must be disposed.– Air pollution from toxic gases released during burning of

some trash.

Reducing Solid WasteThe 3 R’s – Reduce, Reuse, Recycle

1. Reduce Buy less - buy products that

use less packaging or that last longer

2. Reuse Buy reusable – rechargable,

refillable, etc.3. Recycle

Reusing materials or recovering valuable materials from waste or scrap

Recycling Benefits• Making products from

recycled materials saves energy, water, and other resources.

– 95% less energy is needed to produce aluminum from recycled aluminum than from ore.

– 70% less energy is needed to make paper from recycled paper than from trees.

Composting• The process of allowing plant waste to

decompose into a dark brown material that can be used in gardens to enrich soil.

Making Different Choices

• Changing the materials we use could eliminate many of the wastes we create.

Ex: juice boxes

• Paper vs. Plastic?