Wastewater Practice exam: Questions &
Answers
When organic wastes are discharged to receiving waters, O2 is depleted by _____. (Ans- bacteria
Hydrogen sulfide gives off an odor similar to____.(Ans- rotten eggs
- diseases potentially carried by wastewater are _____.
(Ans- typhoid fever, dysentery, cholera
Immediate first aid for burns is to ____.(Ans- flood with cold water
What most likely causes an electric motor failure?(Ans- moisture
What mixed liquor characteristics indicate a healthy activated sludge process?(Ans- brown color, frothy appearance, and musty odor
T/F: Algae is a plant life necessary for the proper functioning of a
stabilization or oxidation pond.(Ans- True
Chlorine gas is ?(Ans- heavier than air
T/F: The highest concentration of algae growth in a facultative lagoon is
usually observed near the top.(Ans- True
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Common hydraulic detention times for primary clarifiers range from ____ hours (Ans- 2 - 3 hours
T/F: Methane is produced in an anaerobic digester and can be used as a
fuel?(Ans- True
T/F: The rock in a trickling filter is usually placed on a tile underdrain
system.(Ans- True
What is the purpose of heating and mixing a primary anaerobic digester?(Ans- to increase the digestion rate
T/F: Exhaust from a chlorinator room should be taken form floor level.
(Ans- True
T/F: Chlorine residual may be determined using the reagent _____
(Ans- diethyl-p-phenylene diamine (DPD)
What test is typically never performed on wastewater influent?(Ans- fecal coliform
Considering the layout and flow diagram for the complete treatment plant, oxidation ditch plants would be most similar to _____?(Ans- extended aeration
The pressure against which a pump must operate is measured in terms of _____ (Ans- Kpa (psi)
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