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. Most of MSW is paper, yard wastes, plastics, and food.

2. 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 recycleCompostBurn the trashBioremediation

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.

DrawbacksCan 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.