Title: http:www.epa.gov
1http//www.epa.gov/
2Waste Management
Composition of Waste
Disposal Landfills,
Incineration, Composting
Recycling reuse (source reduction)
3Composition of Waste
Before recycling
So, all we need to do is recycle, right?
4This is what happens after recycling
5How do we dispose the waste?
6What to dispose?
There are two ways to bury trash
- Dump
- Landfill
7What is a dump?
Dump - an open hole in the ground where trash is
buried and that has various animals (rats, mice,
birds) swarming around. (This is most people's
idea of a landfill!)
8And what is a Landfill?
- Landfill - carefully designed structure built
- into or on top of the ground in which trash
- is isolated from the surrounding environment
- (groundwater, air, rain). This isolation is
- accomplished with a bottom liner and daily
- covering of soil.
9LANDFILL
10The basic parts of a landfill
Bottom liner system - separates trash and
subsequent leachate from groundwater
Cells (old and new) - where the trash is stored
within the landfill
Storm water drainage system - collects rain water
that falls on the landfill
Leachate collection system - collects water that
has percolated through the landfill itself and
contains contaminating substances (leachate)
Methane collection system - collects methane gas
that is formed during the breakdown of trash
Covering or cap - seals off the top of the
landfill
11Landfill Cross-section
12WHAT IS A BOTTOM LINER?Â
One or more layers of clay or a synthetic
flexible membrane. If the bottom liner fails,
wastes will migrate directly into the
environment.Â
There are three types of liners clay, plastic,
and composite. State-of-the-art plastic (HDPE)
landfill liners are 100 mils or 1/10 of an inch
thick.
13Sanitary and MSW
Sanitary landfill -
landfill that uses a clay liner to isolate the
trash from the environment
Municipal solid waste (MSW) landfill
uses a synthetic (plastic) liner to isolate the
trash from the environment
14LEACHATE
Leachate is water that gets badly contaminated by
contacting wastes.Â
It seeps to the bottom of a landfill and is
collected by a system of pipes.Â
The pumped leachate is treated at a wastewater
treatment plant (and the solids removed from the
leachate.)
15Seepage of Leachate
16WHAT IS A COVER?
A cover keeps water out (leachate formation).Â
It consists of sloped layers
clay or membrane liner
overlain by a very permeable layer of sandy or
gravelly soil (to promote rain runoff),
overlain by topsoil in which vegetation can root
(to stabilize the underlying layers).Â
17An experimental covering
18CONSTITUENTS IN LANDFILL GAS
Component          Percent (dry volume basis)
- Methane                           Â
40-60 - Carbon Dioxide                 40-60
- Nitrogen                                2-5
- Oxygen                            Â
0.1-1.0 - Ammonia                         Â
0.1-1.0 - Sulfides, disulfides,etc.       0-0.2
- Hydrogen                           0-0.2
- Carbon Monoxide               0-0.2
- Trace Constituents           0.01-0.6
- Exact percent varies with the landfills age.
19Disposal of Methane
Communities are increasingly finding ways to use
the gas as a source of energy.
20Combustion and Incineration
Controlled burning
Combustors convert water into steam to generate
heat or electricity.
Burning Municipal solid waste (MSW) can generate
energy while reducing the amount of waste by up
to 90 percent in volume and 75 percent in
weight.
21Incineration Facility
22Drawbacks of Combustion
Does not eliminate waste, but changes the form of
waste into possible hazardous air emissions and
toxic ash.
Spreads hazardous contamination worldwide
contaminating air, soil, and water.
Is a major source of 210 different dioxin
compounds, plus mercury, cadmium, nitrous oxide,
hydrogen chloride, sulfuric acid, fluorides, and
particulate matter small enough to lodge
permanently in the lungs.
23Benefits of Composting
Keeps organic wastes out of landfills.
Provides nutrients to the soil.
Increases beneficial soil organisms (e.g., worms,
centipedes).
Suppresses certain plant diseases.
Reduces the need for fertilizers and pesticides.
Protects soils from erosion.
Assists pollution remediation.
24Benefits of recycling
- Conserves resources.
- Prevents emissions of greenhouse gases and
- water pollutants.
- Saves energy.
- Supplies raw materials to industry.
- Creates jobs.
- Stimulates the development of greener
technologies. - Reduces the need for new landfills and
incinerators.
25Changes in Recycling Rates
26Recycling of Materials
27Reusing materials to minimize waste products
- Use durable coffee mugs.
- Use cloth napkins or towels.
- Refill bottles.
- Donate old magazines or surplus equipment.
- Reuse boxes.
- Turn empty jars into containers for leftover
food. - Purchase refillable pens and pencils.
- Participate in a paint collection and reuse
program.
28Trend
29Recycle
http//www.p2pays.org/recycleguys/teachers.asp
http//www.kidsrecycle.org/green_schools.php