HSC 4201 Chapter Notes - Chapter 14: Aeration, Aerobic Organism
Document Summary
Occurs in a sedimentation tank: also called a clarifier. The wastewater remains in quiescent condition for about 2 to 4 hours. Heavier solid particles settle to the bottom forming a layer referred to as sludge: sludge . Above the sludge remains most of the wastewater, including many bacteria and chemicals. On top of this aqueous layer is a layer of oils and fats called scum. Layers of sludge and scum are removed, and the clarified wastewater enters the secondary stage of treatment. Aerobic bacteria are added and mixed with clarified wastewater to break down the organic waste. This mixture then flows to aeration tanks: oxygen is continuously added to support the aerobic decomposition of organic waste into: This biological process is completed after about 6 to 10 hours. The wastewater is sent to sedimentation tanks, where solids and flocks of bacteria are separated from the treated liquid portion of wastewater in quiescent conditions.
