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41 Cards in this Set
- Front
- Back
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What is the best method of collecting a sample to be tested for effluent chlorine residual? A. Composite sample at the inlet of the chlorine contact chamber B. Grab sample at the outlet of the chlorine contact chamber C. Composite sample at the outlet of the chlorine contact chamber D. Grab sample at the inlet of the chlorine contact chamber |
Grab sample at the outlet of the chlorine contact chamber |
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Which is the physical process that follows an aeration tank? A. Preliminary treatment B. Tertiary treatment C. Activated sludge process D. Secondary clarification |
Secondary clarification |
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What is the principle concept of the gravity belt thickener? A. Dewaters through pressure shearing B. Thickens through gravity drainage C. Thickens through high speed spinning D. Thickens through pressure filtration |
Thickens through gravity drainage |
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What percentage of total suspended solids (TSS) is typically removed in primary clarifier? A. 25% B. 100% C. 50% D. 85% |
50% |
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What color should digested sludge be in a properly operated anaerobic digestion process? A. Black B. Grey C. Green D. Brown |
Black |
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Which activated sludge growth phase is considered to have the lowest F/M ratio, the highest SRT, the lowest sludge yield, and the worse oxygen utilization efficiency? A. High rate aeration B. Extended aeration C. Conventional aeration D. Log growth |
Extended aeration |
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Which test is not used to indicate the performance of an anaerobic digester? A. Alkalinity B. Methane gas production C. PH D. Chlorine residual |
Chlorine residual |
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What is the guideline velocity number to accomplish proper grit removal? A. 2 fps B. 1 fps C. 10 fps D. 5 fps |
1 fps |
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Why should air be prevented from entering an anaerobic digester tank? A. It reduces the gas storage capacity of the tank B. It interferes with the activity of the aerobic bacteria C. It lowers the temperature of the digested sludge D. It can react with the digester gas and create a potential for an explosion |
It can react with the digester gas and create a potential for an explosion |
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What is the typical percent solids in the final cake of a belt filter press? A. 2% to 4% B. 30% to 50% C. 15% to 20% D. 8% to 10% |
15% to 20% |
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What adjustment is generally necessary when gas and or solids rise to the surface of a primary clarifier? A. Increase the amount of primary sludge withdrawal B. Stop pumping primary sludge C. Load the primary clarifier at a higher rate D. Decrease the amount of primary sludge withdrawal |
Decrease the amount of primary sludge withdrawal |
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What color should the digester gas be, as it is being burned in a waste gas burner, when the methane content is very high? A. Yellow B. Amber C. Green D. Blue |
Blue |
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Which test is not recommended to use for process control of an anaerobic digestion process? A. pH B. Acid/alkalinity C. Volatile reduction D. Methane gas production |
pH |
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What are the vector attraction reduction requirements for lime stabilization to accomplish class b stabilization standards? A. Raise the sludge pH to no more than 11.0 B. Raise the sludge pH to at least 12 for the first 2 hours, and then at least 12.5 for the next 24 hours C. Raise the sludge pH to between 10.0 to 10.5 D. Raise the sludge pH to at least 12 for the first 2 hours, and then at least 11.5 for the next 22 hours |
Raise the sludge pH to at least 12 for the first 2 hours, and then at least 11.5 for the next 22 hours |
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What may be the result if the system tension pressure of a belt filter press is increased too much? A. The floc size may be too small B. The belts may be blind C. Gravity filtration will be too clear D. The cake solids may be too high |
The belts may be blind |
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Which component may create the highest maintenance requirements in a uv disinfection system? A. UV monitor B. UV lamp C. UV abilitator D. Uv residual |
UV lamp |
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Where is gas chlorine withdrawn from in a one-ton container? A. From the bottom valve B. From the top valve C. From top or bottom valves D. Has cannot be withdrawn from a one ton container |
From the top valve |
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If a grit chamber is passing grit through the tank, what adjustment should be made to the velocity? A. Increase the velocity B. Decrease the velocity C. The velocity must be higher than 3.0 fps to function D. Velocity has nothing to do with grit removal |
Decrease the velocity |
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Which operating parameter is common for a conventional activated sludge process? A. D.O between 4.0 to 5.5 mg/L B. SRT between 4 to 8 days C. RAS to Q ratio about 150% D. F/M ratio between 0.1 to 0.15 |
SRT between 4 to 8 days |
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Which factor may have the least affect on the operation of an aerobic digester? A. Digester detention time B. Temperature of the digesting sludge C. Oxygen transfer efficiency D. Organic nitrogen level in the sludge feed |
Organic nitrogen level in the sludge feed |
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What is the term that identifies the probable number of fecal coliform in wastewater effluent? A. COD B. MPN C. pH D. D.O. |
MPN |
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What is the amount of oxygen credit received for each ppm of nitrate used as a source of oxygen in the denitrification process? A. 2.8 pounds B. 3.6 pounds C. 4.6 pounds D. 7.2 pounds |
2.8 pounds |
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What happens to the pH of the digesting sludge if the aeration to an aerobic digestion system is periodically shut off? A. The pH will decrease B. The pH will increase C. Aeration of the digester has nothing to do with the pH D. The alkalinity will decrease |
The pH will increase |
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Which activated sludge growth phase is considered to have the highest f/m ratio, the lowest srt, the highest sludge yield, and the best oxygen utilization efficiency? A. High rate aeration B. Extended aeration C. Conventional aeration D. Declining growth |
High rate aeration |
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How is fecal coliform identified in the membrane filter test method? A. The number of colonies grown on the filter paper B. The number of positive tubes C. The number of negative tubes D. The number of colonies grown in the tub |
The number of colonies grown on the filter paper |
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Which type of wastewater typically has the highest demand for oxygen? A. Domestic B. Storm water C. Sanitary D. Industrial |
Industrial |
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Is is hydrogen sulfide (H²S) lighter or heavier than the weight of air? A. Lighter, it will rise B. Heavier, it will settle C. No difference, they are both the same weight D. Hydrogen sulfide has a neutral weight |
Heavier it will settle |
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Which zone produces the largest amount of biological nitrification? A. Fermentation B. Anoxic C. Aerobic D. Reaertion |
Aerobic |
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Which zone of BNR plant produces a release of phosphorus for later uptake in the downstream zones? A. Anoxic B. Fermentation C. Aerobic D. Reaeration |
Fermentation |
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What is the purpose of an Imhoff cone test? A. To identify total suspended solids B. To identify setteable solids C. To identify volatile solids D. To identify fixed solids |
To identify settable solids |
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What is the makeup of typical grit debris? A. Organic material B. Dissolved solids C. Inorganic material D. Volatile solids |
Inorganic materials |
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Which is the biological process that follows primary treatment? A. Preliminary treatment B. Tertiary treatment C. Activated sludge process D. Secondary clarification |
Activated sludge process |
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Which aeration foam may indicate a young sludge condition? A. Black in color B. Dark brown in color C. White or very light in color D. Very dark Grey in color |
White or very light in color |
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What adjustment should be made if solids are rising in the secondary clarifier accompanied by small nitrogen gas bubbles? A. Increase aeration D.O. B. Decrease the RAS rate C. Decrease the WAS rate D. Decrease aeration D.O. |
Decrease aeration D.O. |
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Which component is not part of a centrifugal pump? A. Check valve B. Impeller C. Bearings D. Rotor |
Rotor |
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Which problem is the more likely cause of pumps and pipes clogging and requiring cleaning to restore normal flow rates? A. Poor screenings removal B. Poor BOD removal C. Poor TSS removal D. Poor NH³ conversion |
Poor screenings removal |
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What is a common spacing between bars for a fine bar screen? A. 2 inches B. ¼ inch C. 4 inches D. 1 micron |
¼ inch |
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What causes sludge to float to the surface in the dissolved air flotation (DAF) process? A. The addition of lime B. The addition of polymer C. The addition of air saturated recycle water D. Withdrawing bottom sludge at a fast rate |
The addition of air saturated recycle water |
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What percentage of CBOD⁵ is typically removed in a primary clarifier? A. 25% B. 100% C. 50% D. 75% |
25% |
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Where does the D.O. come from in an unaerated lagoon? A. Wind blowing across the pond B. Algae growth C. Oxygen producing bacteria D. The moon |
Algae growth |
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Which lab test requires the use of an analytical balance, a drying oven , filter papers, and a desiccator? A. TSS B. TS C. CBOD⁵ D. Settleable solids |
TSS total suspended solids |
