Wastewater Grade III Practice Test Questions with Verified Answers| Latest
Update Graded A+
Nitrogen and carbon dioxide gas are non-flammable and have no odor, but can both cause
asphyxiation at concentrations greater than normal.
( )True
( )False ( )True
Explanation:
Nitrogen and carbon dioxide gas are non-flammable and have no odor, but can both cause
asphyxiation at concentrations greater than normal.
You are required to maintain an MSDS file for chemicals that are hazardous and stored in
quantities greater than 100 pounds or 10 gallons.
( )True
( )False ( )False
MSDS records are required for all hazardous chemicals used in the work place regardless of the
quantity.
Most nitrogen in raw domestic wastewater is in the form of organic compounds such as
proteins or nitrate salts.
( )True
( )False ( )False
Explanation:
Most nitrogen in raw wastewater is in the form of ammonia.
Water temperature, TDS, and Altitude all affect the amount of Oxygen that can dissolve in
water. (Dissolved Oxygen = DO)
( )True
( )False ( )True
,Explanation:
Water temperature, TDS, and Altitude all affect the amount of Oxygen that can dissolve in
water.(Dissolved Oxygen = DO)
MCRT and the F/M ratio are directly related. (A short MCRT means a low F/M)
( )True
( )False ( )False
Explanation:
MCRT and the F/M ratio are INVERSELY related. (A SHORT MCRT means a HIGH F/M)
INVERSELY = Opposite
NPDES is an acronym for National Pollution Discharge Elimination System.
( )True
( )False ( )False
Explanation:
NPDES is an acronym for National POLLUTANT Discharge Elimination System.
Sodium thiosulfate is often used to dechlorinate a secondary effluent BOD sample.
( )True
( )False ( )False
Explanation: Secondary BOD samples generally do not contain chlorine, therefore there is no
need to dechlorinate.
The best indicator of the effectiveness of the disinfection process is:
( )HPC test
( )Coliform test
( )Effluent turbidity
, ( )Chlorine dose in ppm
( )Chlorine residual ( )Coliform test
Explanation: The coliform test is used to monitor the effectiveness of the disinfection process.
For a plant that uses the F/M ratio to control the activated sludge process, an increase in BOD
or COD load requires an increase in microorganism mass.
( )True
( )False ( )True
Explanation: For a plant that uses the F/M ratio to control the activated sludge process, an
increase in BOD or COD load requires an increase in microorganism mass.
High I/I (Infiltration and Inflow) can contribute to poor performance of the primary and
secondary treatment systems.
( )True
( )False ( )True
Explanation: High I/I (Infiltration and Inflow) can contribute to poor performance of the primary
and secondary treatment systems.
Explanation: High I/I (Infiltration and Inflow) can contribute to poor performance of the primary
and secondary treatment systems.
Which of the following is within normal operating range for a DAF thickening waste activated
sludge using polymer?
( )A solids recovery value of 50%
( )A solids loading rate of 1.0 lbs/sq ft/hr
( )All of above values are normal
( )A floating solids concentration of 0.9%
( )Air to solids ratio of 2:1 ( )Air to solids ratio of 2:1
Explanation: Normal ranges for a DAF using polymer are: Air to solids ratio - 0.01-0.1 lbs/lbs;
Solids loading rate - 24-48 lbs/day/ft2; Hydraulic loading - 0.5-2.0 gpm/ft2; Floating solids - 3%-
Update Graded A+
Nitrogen and carbon dioxide gas are non-flammable and have no odor, but can both cause
asphyxiation at concentrations greater than normal.
( )True
( )False ( )True
Explanation:
Nitrogen and carbon dioxide gas are non-flammable and have no odor, but can both cause
asphyxiation at concentrations greater than normal.
You are required to maintain an MSDS file for chemicals that are hazardous and stored in
quantities greater than 100 pounds or 10 gallons.
( )True
( )False ( )False
MSDS records are required for all hazardous chemicals used in the work place regardless of the
quantity.
Most nitrogen in raw domestic wastewater is in the form of organic compounds such as
proteins or nitrate salts.
( )True
( )False ( )False
Explanation:
Most nitrogen in raw wastewater is in the form of ammonia.
Water temperature, TDS, and Altitude all affect the amount of Oxygen that can dissolve in
water. (Dissolved Oxygen = DO)
( )True
( )False ( )True
,Explanation:
Water temperature, TDS, and Altitude all affect the amount of Oxygen that can dissolve in
water.(Dissolved Oxygen = DO)
MCRT and the F/M ratio are directly related. (A short MCRT means a low F/M)
( )True
( )False ( )False
Explanation:
MCRT and the F/M ratio are INVERSELY related. (A SHORT MCRT means a HIGH F/M)
INVERSELY = Opposite
NPDES is an acronym for National Pollution Discharge Elimination System.
( )True
( )False ( )False
Explanation:
NPDES is an acronym for National POLLUTANT Discharge Elimination System.
Sodium thiosulfate is often used to dechlorinate a secondary effluent BOD sample.
( )True
( )False ( )False
Explanation: Secondary BOD samples generally do not contain chlorine, therefore there is no
need to dechlorinate.
The best indicator of the effectiveness of the disinfection process is:
( )HPC test
( )Coliform test
( )Effluent turbidity
, ( )Chlorine dose in ppm
( )Chlorine residual ( )Coliform test
Explanation: The coliform test is used to monitor the effectiveness of the disinfection process.
For a plant that uses the F/M ratio to control the activated sludge process, an increase in BOD
or COD load requires an increase in microorganism mass.
( )True
( )False ( )True
Explanation: For a plant that uses the F/M ratio to control the activated sludge process, an
increase in BOD or COD load requires an increase in microorganism mass.
High I/I (Infiltration and Inflow) can contribute to poor performance of the primary and
secondary treatment systems.
( )True
( )False ( )True
Explanation: High I/I (Infiltration and Inflow) can contribute to poor performance of the primary
and secondary treatment systems.
Explanation: High I/I (Infiltration and Inflow) can contribute to poor performance of the primary
and secondary treatment systems.
Which of the following is within normal operating range for a DAF thickening waste activated
sludge using polymer?
( )A solids recovery value of 50%
( )A solids loading rate of 1.0 lbs/sq ft/hr
( )All of above values are normal
( )A floating solids concentration of 0.9%
( )Air to solids ratio of 2:1 ( )Air to solids ratio of 2:1
Explanation: Normal ranges for a DAF using polymer are: Air to solids ratio - 0.01-0.1 lbs/lbs;
Solids loading rate - 24-48 lbs/day/ft2; Hydraulic loading - 0.5-2.0 gpm/ft2; Floating solids - 3%-
