1. Nature of ecosystems Energy flow – microbes are decomposers Water
Carbon
Nitrogen

2. Nitrogen Fixing Bacteria
Nitrifying Bacteria
N2 to NH3
Cyanobacteria
Methylotrophic bacteria
Rhizobium – symbiotic

3. Water Pollution
Chemical
Biological
Indicator organism – E. coli

4. Coliform Tests Membrane Test MUG (ONPG) Test Water is filtered
______________ is placed on agar
Colonies are counted
MUG (ONPG) Test
Fluorescence (yellow color) indicates E. coli presence

5. Sewage Treatment Sewage – used water Primary
Solids separated from liquid
Floating ____________ is shredded
Skimmers remove ___________________
___________________ recovered
Organic solids (__________) removed

6. Secondary Sewage treatment
Activated sludge treatment
Air is pumped into liquid in a tank
Microbes are added as a sludge and decompose organic material
Trickling filtration
Sewage aerated by spraying
Moves over a layer of aerobic microbes on rocks
80% removal of organic matter (BOD)

7. Tertiary Sewage Treatment
Filters can remove the last 5-20% of organics
Costly process
Applications: