solid waste
DESCRIPTION
Solid waste notesTRANSCRIPT
Solid Waste Any discarded material that is
not liquid or gas (junk mail, coffee grounds, junked cars, etc.)
* about 6 pound/person /day
Where does our trash go?
In 2007 almost 65% of the solid wastes produced in U.S. went to 2,500 sanitary landfills.
Sanitary Landfills– waste disposal facility where wastes are put in the ground and covered each day with a layer of soil.
* Safer than open dumps (habitat for obnoxious smell, flies & Rats).
Leachate – liquids that drain from landfill. Contains dissolved chemicals from decomposing garbage.
leachate can get into ground water, making nearby wells unsafe.
.
Methane Gas is formed when wastes decompose without oxygen.
can seep through ground and into basements of nearby homes: one spark can blow up a house.
“NIMBY” – not in my backyard attitude makes it difficult to find landfill sites.
Finding acceptable locations – clay soils, stable bedrock, far from aquifer.
EPA Regulations for landfills – effective 1993
synthetic or clay liners
collecting and treating leachate
monitoring for escaping methane gas ( install vent pipes for escaping gas)
Monitor ground and surface water
Sanitary Landfill Design
Incinerators – burn trash
17% of trash is burned in U.S.
Japan and Switzerland burn more than 50% of their trash.
Advantages of Burning Trash
Reduces the volume of waste by 90%
Provides energy – Waste to energy plants – burn wastes to produce steam for electricity.
Disadvantages of Burning Trash:
Polluting gases ( carcinogens)
Ash Disposal ( may contain heavy metals which are hazardous wastes, Ex. cadmium, mercury, lead)