AP Environmental Science / Unit 8: Aquatic and Terrestrial Pollution
8.11 Sewage Treatment
Notes
- Primary treatment: physical removal of solids (settling).
- Secondary: bacteria break down organic matter.
- Tertiary: removes nutrients (N, P) and other pollutants.
- Disinfection (chlorine, UV) kills pathogens.
Practice
Bacteria break down organic matter in:
Biological step.
Primary treatment removes:
Physical step.
Combined sewer systems can overflow during:
Stormwater overwhelms them.
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