WASTEWATER
By Rick Lallish
What operational parameters are able to be controlled by the operator in an activated sludge treatment process?
A. BOD load, hydraulic load and detention timesB. Influent solids, flow and solids retention timeC. Dissolved oxygen, return rate and wasting rateD. Weather, flow and demand
ANSWER: C. The activated sludge process has many variables to be aware of, but operators have total control over only these three. Operators may set the DO to the point necessary to maintain aerobic conditions and fulfill the needs of the microorganism population. They also can set the return rate to ensure that the sludge can settle
