Biological Treatment

Aeration Tanks: 

Aeration TanksThe water travels into the aeration tanks where microorganisms consume the soluble pollutants suspended solids as a food source. The aeration blowers add oxygen into the water for the microorganisms to thrive by mixing the tanks, it brings the food and organisms together.

Secondary Clarifiers: 

Primary Clarifier The flow leaves the aeration tank and enters the secondary clarifiers. During this process, the microorganism clump together and form a floc. There, organisms settle at the bottom of the tanks are removed as Returned Activated Sludge (RAS).  

Returned Activated Sludge:

RAS Pumps and Blowers The RAS is pumped back to the inlet of the aeration tanks where the organisms repeat their cycle. A portion of the RAS is diverted to the solids handling process for further treatment. This is called the Wasted Activated Sludge (WAS). The WAS helps keep a balance in the water system as the organisms continue to multiply.  This WAS is also how phosphorous is removed from the water since it is contained within the organisms.