Questions And Correct Answers
Turbidity in wastewater is caused by
A. color
B. dissolved calcium
C. hardness
D. finely divided suspended material
D. finely divided suspended material
The gas most commonly associated with septic wastewater is
A. carbon dioxide
B. carbon monoxide
C. hydrogen sulfide
D. methane
C. hydrogen sulfide
How many cubic meters per second in 10 MGD?
A. 0.44
B. 1.44
C. 4.73
,D. 24.62
A. 0.44
Mechanical ventilation of a lift station is required to
A. lower temperatures to reduce proportion of hydrogen sulfide
B. reduce chlorine demand
C. reduce corrosion
D. increase DO in raw wastewater
C. reduce corrosion
A wet well probe is usually used for ________ determination(s) of level.
A. approximate
B. dual point
C. continuous
D. single point
D. single point
A pump is delivering at less than the expected rate of discharge. Which of the causes
listed below is incorrect?
A. speed of motor too low
B. pump not primed
,C. impeller clogged
D. discharge head too low
D. discharge head too low
Metal pipes often fail because of
A. back siphonage
B. browning movement
C. galvanic action
D. reverse osmosis
C. galvanic action
When a fire hydrant is operated, it should be
A. just opened enough to have a flow
B. opened fully
C. opened halfway
D. regulated to flow required
B. opened fully
If the pump bearings on horizontal centrifugal pumps are over lubricated, the most
important effect is that the extra lubricant
A. will result in smoother and more efficient operation of the pump
, B. will not make any difference in the operation of the pump
C. will be wasted
D. shaft or shaft sleeve will be damaged
D. shaft or shaft sleeve will be damaged
If packing is not maintained properly,
A. cavitation damage will result
B. impeller will corrode
C. loss of suction due to air being allowed to enter pump
D. shaft or shaft sleeve will be damaged
C. loss of suction due to air being allowed to enter pump
Air flow through a trickling filter when the influent is warmer than the air temperature
is
A. upward through the filter
B. downward through the filter
C. inadequate and may require forced air ventilation
D. improved by decreasing the recirculation
A. upward through the filter
An active sludge in the aeration tank with an abundant available food supply will have
a relatively