APES - Municipal Water Systems

First step of wwtp

Grit chamber - small basin where suspended solids settle out via sedimentation; low residence time; removes sand, gravel

Second step of wwtp

Bar screen - bars which block out large solids; filtration; removes trash, rocks, leaves

Third step of wwtp

Primary Clarifier - large tank with very low carrying power and long residence time and skimmer on surface; removes small suspended solids via sedimentation and grease on surface via skimming; removes dirt, feces, toilet paper (50-70%)

Fourth step in wwtp

Anoxic tank - tank with little to no oxygen encourages bacteria to absorb nutrients

Fifth step in wwtp

Aeration tank - air and O2 bubbled through water to mix it and encourage aerobic decomposition and reproduction of bacteria; bacteria absorb nutrients (nitrate, nitrite, phosphate) and break down organic waste (food, feces)

Sixth step in wwtp

Secondary clarifier - like primary clarifier; allows flocc to settle out via sedimentation; removes 95-97% of all organic matter like feces, toilet paper, food, soap

Seventh step in wwtp

Disinfection/chlorination tank - bleach NaClO added to effluent to kill 99% of viruses, bacteria, and protozoans in the water

Eighth step in wwtp

Sludge digesters

1st form of pollution

Disease-causing agents - Harmful parasites / microbes (bacteria, viruses, protozoans, roundworms)

2nd form of pollution

Inorganic chemicals - highly toxic metals which dissolve in water (Lead, mercury, copper, arsenic, chromium)

3rd form of pollution

Synthetic organic compounds - manmade organic substances which are harmful to aquatic ecosystems (detergent, oil, pesticide, industrial waste)

4th form of pollution

Fertilizers - Additional plant nutrients used in agriculture to speed up plant growth (Nitrogen-rich fertilizers)

5th form of pollution

Sediment - broken down/weathered rocks and minerals (soil, silt, clay)

6th form of pollution

Oxygen-demanding wastes - matter which is aerobically decomposed by bacteria, using up DO (sewage, manure, industrial or organic wastes)

7th form of pollution

Radioactive wastes - extremely toxic, cell-damaging particles (nuclear fuel, radioactive rocks)

8th form of pollution

Thermal pollution - Things which unnaturally increase the temperature of a body of water (water used to cool generators)

1st step of mwt

Bar screen

2nd step of mwt

Grit chamber

3rd step of mwt

Ozonation

4th step of mwt

Flocculation

5th step of mwt

Sedimentation

6th step of mwt

Sand and charcoal filtration

7th step of mwt

Chemical addition

8th step of mwt

Storage and distribution