WASTEWATER
By Rick Lallish
What process control measure has the most influence on sludge quality and determines the sludge age in an activated sludge process?
A. RAS (return activated sludge)
B. WAS (waste activated sludge)
C. SVI (sludge volume index)
D. F/M (food to mass ratio)
Answer: B. In an activated sludge facility, the operator must understand each process control measure. This includes understanding how measures such as RAS and WAS affect sludge quality. Operators must also know when to adjust and use these parameters to operate the plant to meet effluent standards. WAS is the measure that determines how long the mixed liquor suspended
