1. Chapter 4 Land and Soil Resources
Section 2
Solid Waste
Notes 4-2

2. Trash Facts Each day, one American produces 10 kg of trash.
Every hour, people throw away 2.5 million plastic bottles.
Every two week, there is enough glass bottles and jars thrown away to fill the Twin Towers.
Every year, people throw away 1.6 billion pens, 2.9 million tons of paper towels and 220 million tires.

3. Problem of Waste Disposal
Solid Waste:
Things that people throw away
Some can be liquid
Most is produced by agriculture, mining and industry
Municipal Waste:
Produced by homes, business and institutions
Can be buried, burned or maybe recycled

4. Problem of Waste Disposal
Landfills:
Old land fills were just holes in the ground
Not safe and unsightly
Sanitary Landfills:
Constructed to hold wastes more safely
Holds solid waste, construction debris, agricultural and industrial wastes
Covered with clay and soil, then grass and trees
Keeps leachate from forming
Polluted water that filters through the waste and gets into drinking water

5. Problem of Waste Disposal
Parts of a Landfill:
Leachate collection: polluted water collects at the bottom
Liners: thick layers of clay and plastic cover the bottom and sides; keeps liquid from leaking into the soil
Solid waste Layers: compacted waste reduces volume; covered with soil or plastic

6. Problems of Waste Disposal
Parts of a Landfill (cont)
Gas recovery: bacteria break down wastes and produce methane and carbon dioxide; gases can build up and cause explosions. Vent pipes collect the gases and release them
Leachate treatment: leachate is pumped into holding ponds and treated; then shipped to safe disposal sites
Monitoring wells: water wells are tested to make sure leachate is not escaping out of the landfill

7. Problems of Waste Disposal
Incineration:
Burning of solid wastes
Pros
Incinerators take up less space than landfills
Don’t pose a risk of polluting the water
Heat can be used to produce electricity
Cons
Can release some pollutants into the air
Some wastes are left over
More expensive to build than landfills

8. Recycling Process of reclaiming raw materials and reusing them
Reduces the volume of solid waste
Matter is naturally recycled in nature
Biodegradable: broken down and recycled by bacteria and other decomposers
Four major categories of wastes can be recycled
Metal, glass, paper and plastic

9. Recycling Metal: Metals can be melted and reused
Saves money and causes less pollution
No ore needs to be mined, transported to factories and then processes
Conserves nonrenewable resources

10. Recycling
Glass:
Made from sand, soda ash and limestone mixed and then heated
One of the easiest products to recycle
Can be broken down and reheated
Less expensive to recycle than make new
Old pieces melt at lower temps and uses less energy
Less environmental damage caused by mining new materials

11. Recycling Paper: Takes 17 trees to make one metric ton of paper
Turn wood into pulp: thick, liquid
Pulp is spread and dried to make paper
Can use old paper (recycle)
Washed first then mixed with water and chemicals to form pulp
Paper can only be recycled so many times
Each time the paper becomes weaker, rougher and darker

12. Recycling
Plastic:
Resin: solid left over when oil is refined to make gasoline and other petroleum products
Heated, stretched and molded to make plastic products
Number on bottom of plastic container tells what the plastic is made of
Numbers 1 & 2 are often recycled
Make milk jugs, detergent containers and soda bottles

13. Recycling Should we recycle? Conserves resources and saves energy
Can save 90-97% energy by recycling aluminum
4-32% energy by recycling glass
23-74% energy by recycling paper
Not all materials can be recycled
Some can’t be recycled (we don’t know how to)
Some we don’t have a need for after they are recycled
Does produce some pollution and uses energy

14. Recycling Recycling Facts:

15. Solid Waste Management
Most municipal wastes still go to landfills
Recycling is becoming more popular
When materials are brought back, the people are paid a deposit fee.
Encourages people to recycle
Supermarkets recycle their bags and often have bins for other materials as well
Get money for recycling metals

16. “Three R’s” Reduce: Reuse: Recycle: Creating less waste
Finding another use for the object instead of throwing it out
Recycle:
Reclaiming raw materials to create new products

17. Composting
Process of helping the natural decomposition process break down many forms of waste
Yard trash
Leaves, grass clippings
Food waste
Fruit, coffee grounds, egg shells, vegetables
Paper (shredded)
Excellent natural fertilizer for plants