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12 Cards in this Set
- Front
- Back
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1 The typical detention time for an extended aeration plant is how many hours?
10 24 16 32 54 |
24
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2 What is the typical test performed to control the solids in the aeration tank?
30 minute settlability test Mixed liquor suspended solids Dissolved oxygen pH No test will work |
Mixed liquor suspended solids
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3 Calculate the food to microorganism ratio for a aeration tank 60' long, 35' wide, and 17' deep. The MLVSS is 2,500 mg/l, the influent flow is 0.950 MGD, and the BOD5 is 200 mg/l.
0.28 0.23 0.34 28.0 23.0 |
0.28
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4 What are the microorganisms that remove ammonia nitrogen?
Stalked ciliates Rotifers Nitrobactors All of the above None of the above |
Nitrobactors
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5 How many pounds of bio-solids are generated by an activated sludge plant per pound of BOD removed?
1 to 3 0.5 to 0.75 0.1 to 0.5 5 to 10 1 to 7.5 |
0.5 to 0.75
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6 Heavy brown foam is typically caused by which bacteria?
Filamentous Rotifers Stalk ciliates Nocardia Worms |
Nocardia
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7 Stalk ciliates indicate a young sludge.
True False |
False
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8 How many pounds of chlorine per day per 1000 pounds MLSS under aeration are needed to control nocardia?
2 to 4 pounds 10 to 20 pounds 100 to 150 pounds 40 to 50 pounds Chlorine can not be used to control nocardia. |
2 to 4 pounds
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9 Filamentous organisms in an over abundace in the final clarifier may lead to which of the following?
Coning of the sludge. Good settling of the solids. Bulking of the sludge. Low fecal coliform counts in the effluent. All of the above. |
Bulking of the sludge
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10 Five to six filamentous filaments per activated sludge floc particle produces a strong floc particle?
True False |
True
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11 The waste activated sludge flow from a specific treatment plant is 10 gallons per minute (GPM) at a concentration of 2% solids. How many pounds of dry solids are wasted from this facility per day?
2402 Lbs 4204 Lbs 240 Lbs 420 Lbs 14,400 Lbs |
2402 Lbs
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12 Microscopic examination of the activated sludge reveals a few free swimmers and some Amoeba, not much of anything else. This is an indicator of
Excess Solids under aeration. A typical activated sludge biomass that would be expected for a facility that nitrifies. A very old sludge (high sludge age) A young sludge age Over aeration (excess DO) |
A young sludge age
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