SC: A&B -PRACTICE BIOLOGICAL
Latest Exam With 100% Correct
Answers 2026-2027 Updated.
In a centrifugal pump, internal leakage is prevented by ________.
A ) Lantern rings
B ) Wear ring
C ) Flex coupling
D ) Volute - Answer B
Pump and motor shaft wear is caused by ___________.
A ) Discharge pressure too high
B ) Misalignment between pump and motor flanges
C ) Worn out seal
D ) None of the above - Answer B
How many gallons of wastewater would 400 feet of 2 inch pipe hold?
A ) 59.0 gallons
B ) 65.5 gallons
C ) 70.5 gallons
D ) 75.0 gallons - Answer B
What is 74% of 670?
A ) 496
B ) 49.6
C ) 525
D ) 52.5 - Answer A
The amperometric titration method is used to measure _________.
,A ) Chlorine Residual
B ) pH
C ) Total Hardness
D ) Alkalinity - Answer A
In an activated sludge plant the effluent from an aeration basin consist of suspended material
containing large populations of organisms and very little BOD the effluent is called _______.
A ) Influent
B ) Total liquor
C ) Mixed liquor
D ) Activated liquor - Answer C
The quantity of volatile solids in the content of the sludge is an indirect measure of the
________.
A ) Amount of the sample that will evaporate upon standing.
B ) "food" available for the bacteria in the digester.
C ) Number of bacteria in the digester.
D ) Primary effluent suspended solids. - Answer B
The trickling filter removes BOD by ________.
A ) Filtration
B ) Organics trickle down to the media under drain where the micro activity actually takes place
C ) Biological contact throughout the media
D ) Ion exchange - Answer C
A 48-in. diameter pipe is flowing at a rate of 8.5 ft/sec. What is the flow in cu ft/sec?
A ) 17.86
B ) 35.71
C ) 106.76
D ) 521.2 - Answer C
,The evaporation from plants is called ________.
A ) Transpiration
B ) Evaporation
C ) Precipitation
D ) Percolation - Answer A
___________ are well suited for use in nitrification due to the long aeration time for the mixed
liquor and the long sludge age maintained.
A ) Extended aeration facilities
B ) Complete mix facilities
C ) Step feed aeration facilities
D ) All of the above - Answer A
Which parameters are used by municipal sewer authorities to bill industrial users?
A ) Temperature, conductivity and solids
B ) BOD, lead, copper, volatile solids
C ) Copper, chromium, nickel, lead
D ) BOD, D.O., conductivity
E ) Flow, BOD, pH, TSS - Answer E
If a chemical costs $30.00 per ton, how much will it cost per year to treat a flow of 1.5 mgd if
the average dose is 18 mg/l?
A ) $803
B ) $1110
C ) $1233
D ) $1506 - Answer C
Sludge age is one of the methods used by operators to determine and maintain the desired
amount of activated sludge solids in the aeration tank. Sludge age considers two factors vital to
successful operation. They are ________.
A ) Solids entering the treatment process and solids leaving the treatment process
, B ) Solids entering the treatment process and solids being lost through evaporation
C ) Solids entering the treatment process and solids available to treat the incoming wastes
D ) Solids available to treat the incoming wastes and the solids being wasted - Answer C
Which safety equipment is not required when handling caustic soda powder?
A ) Rubber boots
B ) Short sleeved shirt
C ) Safety glasses
D ) Rubber gloves
E ) Face shield - Answer B
Eventually the layer of organisms on the media of a trickling filter gets so thick that some of it
breaks off and is carried into the filter effluent channel. This material is normally called ______.
A ) Algae
B ) Humus
C ) Mixed liquor
D ) Activated solids - Answer B
The clarifier influent contains 2.31 mg/l Cr+6 with effluent concentration of 0.18 mg/l Cr+6.
Determine the efficiency of the clarifier.
A ) 90%
B ) 92%
C ) 94%
D ) 96% - Answer B
The recovery of raw materials and recycling of waste are the objectives of which EPA regulation?
A ) Resource Conservation and Recovery Act
B ) Recycling Chemicals through Recovery Act
C ) Reduction of Chemical Resources and Accumulation
D ) Recovery of Chemicals and Recycling Authority
E ) Resource Chemical and Recycling Act - Answer A
Latest Exam With 100% Correct
Answers 2026-2027 Updated.
In a centrifugal pump, internal leakage is prevented by ________.
A ) Lantern rings
B ) Wear ring
C ) Flex coupling
D ) Volute - Answer B
Pump and motor shaft wear is caused by ___________.
A ) Discharge pressure too high
B ) Misalignment between pump and motor flanges
C ) Worn out seal
D ) None of the above - Answer B
How many gallons of wastewater would 400 feet of 2 inch pipe hold?
A ) 59.0 gallons
B ) 65.5 gallons
C ) 70.5 gallons
D ) 75.0 gallons - Answer B
What is 74% of 670?
A ) 496
B ) 49.6
C ) 525
D ) 52.5 - Answer A
The amperometric titration method is used to measure _________.
,A ) Chlorine Residual
B ) pH
C ) Total Hardness
D ) Alkalinity - Answer A
In an activated sludge plant the effluent from an aeration basin consist of suspended material
containing large populations of organisms and very little BOD the effluent is called _______.
A ) Influent
B ) Total liquor
C ) Mixed liquor
D ) Activated liquor - Answer C
The quantity of volatile solids in the content of the sludge is an indirect measure of the
________.
A ) Amount of the sample that will evaporate upon standing.
B ) "food" available for the bacteria in the digester.
C ) Number of bacteria in the digester.
D ) Primary effluent suspended solids. - Answer B
The trickling filter removes BOD by ________.
A ) Filtration
B ) Organics trickle down to the media under drain where the micro activity actually takes place
C ) Biological contact throughout the media
D ) Ion exchange - Answer C
A 48-in. diameter pipe is flowing at a rate of 8.5 ft/sec. What is the flow in cu ft/sec?
A ) 17.86
B ) 35.71
C ) 106.76
D ) 521.2 - Answer C
,The evaporation from plants is called ________.
A ) Transpiration
B ) Evaporation
C ) Precipitation
D ) Percolation - Answer A
___________ are well suited for use in nitrification due to the long aeration time for the mixed
liquor and the long sludge age maintained.
A ) Extended aeration facilities
B ) Complete mix facilities
C ) Step feed aeration facilities
D ) All of the above - Answer A
Which parameters are used by municipal sewer authorities to bill industrial users?
A ) Temperature, conductivity and solids
B ) BOD, lead, copper, volatile solids
C ) Copper, chromium, nickel, lead
D ) BOD, D.O., conductivity
E ) Flow, BOD, pH, TSS - Answer E
If a chemical costs $30.00 per ton, how much will it cost per year to treat a flow of 1.5 mgd if
the average dose is 18 mg/l?
A ) $803
B ) $1110
C ) $1233
D ) $1506 - Answer C
Sludge age is one of the methods used by operators to determine and maintain the desired
amount of activated sludge solids in the aeration tank. Sludge age considers two factors vital to
successful operation. They are ________.
A ) Solids entering the treatment process and solids leaving the treatment process
, B ) Solids entering the treatment process and solids being lost through evaporation
C ) Solids entering the treatment process and solids available to treat the incoming wastes
D ) Solids available to treat the incoming wastes and the solids being wasted - Answer C
Which safety equipment is not required when handling caustic soda powder?
A ) Rubber boots
B ) Short sleeved shirt
C ) Safety glasses
D ) Rubber gloves
E ) Face shield - Answer B
Eventually the layer of organisms on the media of a trickling filter gets so thick that some of it
breaks off and is carried into the filter effluent channel. This material is normally called ______.
A ) Algae
B ) Humus
C ) Mixed liquor
D ) Activated solids - Answer B
The clarifier influent contains 2.31 mg/l Cr+6 with effluent concentration of 0.18 mg/l Cr+6.
Determine the efficiency of the clarifier.
A ) 90%
B ) 92%
C ) 94%
D ) 96% - Answer B
The recovery of raw materials and recycling of waste are the objectives of which EPA regulation?
A ) Resource Conservation and Recovery Act
B ) Recycling Chemicals through Recovery Act
C ) Reduction of Chemical Resources and Accumulation
D ) Recovery of Chemicals and Recycling Authority
E ) Resource Chemical and Recycling Act - Answer A
