1. Energy Flow in Ecosystems (Section 5.3) Representation by Effect (Section 2.5.4) Biochemical Oxygen Demand (Section 5.4)

2. Energy Flow in Ecosystems

3. Energy fixation Organic matter Autotrophs Heterotrophs Aerobic respiration

4. Energy Flow in Ecosystems Nitrate removal Drinking water Mercury cycling Sludge digestion Anaerobic respiration

5. Energy Flow in Ecosystems Biomass Production Autotrophs Primary producers Algae Phytoplankton Heterotrophs Secondary producers Primary Consumers Herbivores Zooplankton Heterotrophs Secondary consumers Planktivores Heterotrophs Tertiary consumers Piscivores Carnivores (also omnivores)

6. Energy Flow in Ecosystems Food chain Food web

7. Energy Flow in Ecosystems

9. Microbial loop (sustainable?)

10. Other types of units: representation by effect.

13. Organic Matter. … what’s in here?

14. Organic Matter. Carbohydrates (sugar and the polymers starch and cellulose) Proteins (polymers of amino acids) Fats ( Fats (formed from glycerol and fatty acids)

15. Organic Matter. Photosynthesis Respiration also …mineralization oxidation stabilization

16. Representation by Effect - Organic Matter. Respiration When organic matter is used as a substrate for respiration, … when it is oxidized … when it is mineralized … when it is stabilized it exerts a “biochemical oxygen demand” or BOD.

17. BOD - Representation by Effect. … impacts on lakes and rivers?

18. Biochemical Oxygen Demand BOD: the amount of dissolved oxygen (mg/L) required to oxidize the organic matter in water. CBOD: BOD exerted through oxidation of carbonaceous material. NBOD: BOD exerted through oxidation of ammonia.

19. Biochemical Oxygen Demand NBOD is simple stoichiometry, Stoichiometry does not work for CBOD because not all of the organic matter present is biodegradable. Thus the CBOD is never greater and almost always less than the theoretical BOD (ThBOD). but for wastewater, not so much!

20. Biochemical Oxygen Demand L0L0

21. BOD Exerted (y) BOD Remaining (L) Biochemical Oxygen Demand

22. BOD Exerted BOD Remaining Biochemical Oxygen Demand

23. 5-day BOD is a laboratory measurement. Ultimate BOD is for field aplications. Biochemical Oxygen Demand 5-day BOD and Ultimate BOD