1. Nutrient Cycles and Recycling
Unit 3: Resource Sustainability

2. Nutrient cycles
Chemical substance that an organism must obtain from its environment to sustain life and undergo life processes.
These nutrients are recycled so they can be reused!
Water cycle
Carbon cycle
Nitrogen cycle
Phosphorous cycle

3. Water cycle – review!
What’s missing?

4. Carbon Cycle – our game!
All living things contain carbon! Talk about sinks and sources.
How do humans impact this cycle?

5. Nitrogen cycle Very simplified.
Nitrogen fixation – bacteria and lighting convert it so plants can use.
Ammonification – bacteria convert organic to ON to ammonia when animals die.
Nitrification – most plants cannot use ammonium as a form of nitrogen.
Denitrification – back into the atmosphere

6. Phosphorous Cycle
People add nitrogen and phosphorus through eutrophication – what does this cause (in aquatic systems)?

7. (Solid) Waste More to come when we do our trash analysis!
Every year, the U.S. generates more than 10 billion tons of solid waste! (divide per person – what do you get?)
Can be biodegradable or non- biodegradable.
Can it be broken down by biological processes?
Usually comes down to natural v. synthetic materials
Plastics are interesting because they are made primarily of carbon and hydrogen, but not arranged in a way found in nature!

9. Waste Management
Landfills – wastes are put in ground and covered (why?) each day by soil, plastic, or both.
Leachate – liquid that forms from passing through a landfill
Methane – flammable gas produced from landfills
Incinerators – air pollution; some materials cannot be burned
No pollution, or leaching of toxins into the soil or groundwater.

11. Reducing Waste/Recycling
Buying less – products with less packaging, or those that last longer and/or are reusable
Refillable v. disposable bottles (1965) – Tapped movie!
Recycling – saves energy too!
Disposable (by you)
Sorting
Cleaning
Used to make new products
Sold back to you, the consumer!
95% less from recycled aluminum (v. ore), 70% less from recycled paper (v. trees)

12. Reducing Waste/Recycling cont.
Composting (early slide) – yard waste, fruit/vegetable scraps
Enriches the soil!
Plastic bags
Degradable plastics – can break
down in the sunlight, or made
from sugars (usually just broken
down into smaller pieces)