THE FINAL TOUCH:
Biological / Secondary Treatment – Clarifiers
In the second stage of Biological/ Secondary Treatment, the bacteria are separated from the wastewater during a settling process in clarifiers. Some of the biomass is sent back to the reactor tanks to perform additional Secondary Treatment and some is thickened and then sent to the anaerobic digesters.
Each day, about __ tons of solids are recovered during secondary treatment. Over the past 15 years, the City invested $1.6 billion for improvements to this system in order to make the final effluent the cleanest ever produced at the plant.