Transcript SOLID WASTE MANAGEMENT - Woodland Hills School District

SOLID WASTE MANAGEMENT
Objectives:
Identify the methods of disposing of
waste.
Distinguish between reduce, reusing, and
recycling.
A.
Recall how we followed the life cycle of
electricity from coal to our homes.
1. Each step of the way produced wastes.
2. Some of those wastes were released into
the atmosphere or water causing pollution.
(They are essentially unrecoverable).
3. Other wastes are recovered and they can
be: reused, recycled or disposed.
B. Municipal Solid Waste (MSW)
1.
2.
Most of MSW is paper, yard wastes, plastics,
and food.
In the U.S., over 230 million tons of MSW
produced each year.
* Equal to 5 lbs of waste per person per day in the
U.S.
MSW is disposed of in different ways.
3. Landfills are regulated areas where wastes are
placed in the land.
 Landfills
may be specially dug
or constructed on old mining
sites.
 Landfills are designed with a
lining of plastic sheets and
several feet of clay on the
bottom and sides.
 These measures prevent most
substances from leaking out
of the landfill.
 The
wastes are compacted
and covered with several
inches of soil on a daily basis.
 This helps reduce odors and
controls litter, insects, and
rodents.
 Monitoring systems are
installed to catch any
potentially hazardous
materials from leaking.
4. Problems with Landfills.
Odors, litter, insects, rodents, and
leaking wastes
are not the only issues with landfills.
Another problem is landfill gas or LFG that forms
when trash decays. LFG is about 50% methane
and 50% CO2. Both are major contributors to
smog and global warming.
(Some landfills capture the gas and use it to supply
energy.)
The number
of landfills are decreasing as they
become full or shut down due to environmental
problems.
How can we prolong our landfills?
Reduce,
reuse, and recycle
Compost
Burn
the trash
Bioremediation
Currently, PA has
plenty of landfill space. Other
states buy the space and transport their garbage
to PA.
What do
you think about…. allowing other states
to dump their garbage in PA for money?
5. Composting – is a biological method of
waste disposal in which worms, bacteria,
fungi, and other organisms decompose
wastes.
 Only
effective on fruits
and vegetable food
scraps, wood, and
lawn/yard wastes.
 The composted wastes
turn into humus which is
a dark brown substance
rich in nutrients. (A good
component of soil.)
How much is compostable?
6. Combustion of trash - To free up landfill
space, many communities burn their trash.
Benefits
 Reduces volume of
trash by 90%.
 Reduces mass of trash
by 75%
 Destroys harmful
bacteria and chemicals.
 Can generate
electricity.
Drawbacks
 Can pollute the air.
 Needs energy to burn. (in
most cases, the energy
generated is more than
enough to support the
plant)
A W-T-E Power Plant
7. Bioremediation
 When
trash is
broken down in
tanks filled with
bacteria.
 Similar to a septic
system
8. Reduce, Reuse, and Recycle.
The order
is significant because reducing our
consumption is the most important.
Source reduction involves changing the ways
products are made and packaged to reduce
waste. Also changing consumer’s habits from a
“throw-away-society” to more durable and
environmentally friendly products.
 Reusing
products instead
of throwing them away.
 Unused
or older building
supplies or furniture can
be reused. (Construction
Junction in Pgh.)
 Gently
used toys,
furniture, clothes and
household items can be
donated to the Salvation
Army or Goodwill to help
support their mission.
 After
measures are taken to reduce and reuse wastes,
then comes recycling .
 Recycling is a form of reusing except the product’s
materials are manufactured into something new.
 The
first step is collecting: paper, glass, aluminum, steel, and
plastics.
 The second step is manufacturing. Melting down and
reforming into new products.
 The third step is purchasing recycled products. Buying
recycled products encourages business to make and sell more
recycled products. It also saves resources for future
generations.
Recycling: the Good news and Bad news
 The
Good News - Currently about 42% of all paper,
40% of all plastic soft drink bottles, 55% of aluminum
drink cans, and 56% of all steel packaging are being
recycled in the U.S.
 The Bad News - read above plus 2
million plastic soda bottles used in the U.S. every 5 minutes.
 426,000 cell phones retired every day in the U.S.
 1.14 million paper bags used every hour in the U.S.
 106,000 aluminum cans used every 30 seconds in the U.S.
 60,000 plastic bags used every 5 seconds in the U.S.
 15 million sheets of paper used every 5 minutes in the U.S.