Waste Water Operator Lv 1 Exam Prep
In the activated sludge process, some of the activated sludge must be wasted to...
- Prevent excessive solid buildup
- Prevent clogging of the sludge return line
- Prevent overloading of sludge return pumps
- Increase digester gas production
(Ans - A. Prevent excessive solid buildup
The best operating strategy for feeding primary sludge to an anaerobic digester is to feed...
- Several time a day
- Large quantities once or twice a day
- Once a day
- When the volatile solids drop below 60%
(Ans - A. Several time a day
Why is scum skimmed from the liquid surface of a primary settling tank?
- To reduce load on the digester
- To eliminate interference with sludge removal
- To allow aeration of the tank contents
- To reduce odor and insect nuisance
(Ans - B. To eliminate interference with sludge removal
Which of the following test would give the fastest indication of toxicity in an activated sludge process?
- Oxygen Uptake Rate (OUR)
- Settle meter
C. MLSS 1 / 2
- Microscopic Observation
(Ans - A. Oxygen Uptake Rate (OUR)
Filamentous bulking of activated sludge may be controlled temporarily by...
- Adding sodium chloride to the aeration tank
- Spraying water on the aeration tank surface
- Carefully chlorinating the return sludge and mixed liquor
- Aerating the final settling tank
(Ans - C. Carefully chlorinating the return sludge and mixed liquor
Since reaction rates are lower during the winter, the operator of an activated sludge plant will usually...
- Increase dissolved oxygen levels
- Decrease MCRT
- Decrease wasting
- Increase MCRT
(Ans - D. Increase MCRT
In a healthy activated sludge process which of the following organisms will most likely be found in the greatest numbers?
- Stalked Ciliates
- Amoebas
- Free swimming ciliates
- Nymphs
(Ans - A. Stalked Ciliates
Alkalinity is a measure of the ability of wastewater to...
- Neutralize base
- Neutralize acid
- Dissolve organics
- Maintain constant temperature(Ans - B. Neutralize acid
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