1. Reuse, Recycling, and Recovery

2. Flow of materials through human society very much like the flow of nutrients through a natural ecosystem
Materials are extracted from the earth, used in society and then discarded

3. More detailed description:
Size of band is proportional to amount of materials

4. Materials Separation
The key to reuse, recycling and recovery is materials separation.
Separation depends on some readily identifiable characteristic or property of the material that can distinguish it from other materials. This characteristic is called a code.
In recycling the code is usually simple and visual, but sometimes it is not so obvious.
Plastics for example

5. Plastics

6. Desirable Order:
Reuse
Recycle
Recovery

7. Recycling
Biggest problem: a stable market

8. Recovery
Biggest problem: materials separation

9. Refuse-derived Fuel
Classifications
Emissions
dioxin