Solid, Toxic, & Hazardous Waste

. Integrated Science C

Mrs. Brostrom

Objective:

Explain short term and long term impacts of landfills and incineration of waste materials

on the quality of the environment.

The steady flow of varied wastes that get mixed and

deposited in landfills or burned in incinerators. Problems with the waste stream:

Mixing and crushing waste makes accessing valuable resources to recycle difficult and expensive.

Hazardous materials get dispersed throughout the waste making disposal or burning difficult, expensive, and risky.

Spray paint cans, pesticides, batteries (zinc, lead, or mercury) cleaning solvents, plastics that produce dioxins and PCBs when burned are mixed with nontoxic materials.

What is the waste stream?

Landfills receive most of our waste.

A landfill is a permanent waste-disposal facility where wastes are put in the ground and covered each day with a layer of soil, plastic or both; to reduce smell, litter, insects, and rodents; and reduces the spread of disease.

Problems With Landfills

• Leachate• Methane gas

Water percolating through dumps or landfills

dissolves the waste and rusts containers allowing toxins to mix with the water and create leachate.

Some leachate contaminants include: paint, cleansers, pesticides, batteries, heavy metals

However, modern landfills are lined with clay or plastic to prevent the leachate from getting into soil and the groundwater.

Leachate is gathered in pipes that pump it to storage tanks for treatment.

Leachate

When organic waste decomposes away from

oxygen methane is produced. highly flammable gas. “greenhouse gas”. if not monitored, can build up and explode

Since 1984 all new landfills must be lined and have vents to release the methane or combust it as a fuel.

Methane

Incinerators

Solid –waste incinerators reduce the amount of trash that goes to landfills and can be used to generate electricity

Pros: Reduce the weight of

solid waste by 75% Generate electricity

Cons: Materials that are created by

the incinerator can be toxic Waste isn’t sorted- hazardous

materials that shouldn’t be burned are incinerated releasing polluting gases and ash

Ash from incinerators can be more toxic than the waste it originally was.

Trash to Energy Plants

Scrubbers process the smoke produced by

incinerators Scrubbers release small amounts of poisonous

gases and particles of toxic heavy metals into the air

Ash from incinerators has been found to contain high levels of toxins: dioxins, lead, and cadmium

By removing plastics from the garbage before incineration much of the dioxin release is prevented

Batteries release mercury

Hazards of Incinerators