Wastewater Grade 1 Exam Questions with Verified Answers| Latest Update Graded A+
Calculate the SVI if S30 = 460 mL/L, S60 = 443 mgL/L, MLVSS concentration equals 2,850 mg/L,
and MSLSS concentration = 3,800 mg/L.
A. 180 mL/g
B. 121 mL/g
C. 87 mL/g
D. 94 mL/g 121 mL/g
How many gallons/day of primary sludge is collected at the bottom of a primary clarifier if the
influent to the clarifier has a flow rate of 2.1 MGD and a TSS concentration of 250 MG/L. The
effluent from the clarifier has a TSS concentration of 125 MG/L, while the primary sludge is
4.5% solids by weight.
A. 6,892.4 gallons/day
B. 8,241.1 gallons/day
C. 5,833.3 gallons/day
D. 2,597.5 gallons/day Idk look answer up
What is the methane content in a properly operating anaerobic digester? 65 to 70% by
volume
What will the addition of chlorine gas do to the pH of wastewater? Decrease the pH
What is the purpose of a Parshall flume? Measure Flowrate
What is the typical removal efficiency of settable solids in a primary clarifier? 95 to 99%
Pumping scum from a primary clarifier can cause more piping problems than other substances
pumped at a wastewater treatment plant? TRUE.
What might cause thick billows of white sudsy foam in the aeration tank? MLSS is too low
,What does the "M" in F/M ratio represent? The mixed liquor volatile suspended solids in the
aeration tank.
In general, how will warmer temperature affect the settling rate of solids in a clarifier? It
increases the settling rate
What could happen if the digester gas is mixed with air (85 to 95% by volume)? Cause an
explosion
How will algae impact the chlorine demand in the pond effluent? It increase the chlorine
demand
TRUE OR FALSE: A positive displacement pump must NEVER be started with the discharge valve
closed. TRUE
TRUE OR FALSE: The volume of a secondary clarifier is not needed to determine the F/M ratio?
TRUE
Which of the following is one of the basic rules of lab work?
a. Do not leave keys in equipment or vehicles at any time.
b. Patrol the facilities frequently, and look for suspicious activity or behavior.
c. Never Pipet hazardous material with your mouth, even if the pipet has been sterilized.
d. Lock Out and Tag out relevant mechanical and electrical equipment before staring any
maintenance activity. C
What is the recirculation ration for a trickling filter?
A. Qr/Q
B. Q/Qr
, C. Q/Qr+Q
D.Qr+Q/Q A
Which of the following is true about COD and BOD?
A. They are direct measurements of organic content in the influent.
B. They measure the inorganic content of the influent
C. They represent the amount of filamentous bacteria in the influent
D. They are indirect measurements of the organic content in the influent. D
What is the purpose of the grit channel?
A. Remove dissolved and non-settable organics
B. Remove heavy inorganic wastes
C. To allow activated sludge to settle
D. Remove substances that float and readily settle from the wastewater as primary treatment.
B
Which of the following is true about the extended aeration process?
A. Bugs get more food
B. Wasting is not necessary
C. It does not produce as much waste sludge as the other process
D. It is very different from the conventional activated sludge process. C
What is the correct formula for solids in wastewater?
A. Non-volatile solids +Suspended solids = Total solids in the influent
B. Dissolved Solids + Settable Solids = Total Suspended Solids
C. Colloids + Dissolved Solids = Total Suspended Solids
D. Non-settable solids + Settable Solids = Total Suspended solids D
Calculate the SVI if S30 = 460 mL/L, S60 = 443 mgL/L, MLVSS concentration equals 2,850 mg/L,
and MSLSS concentration = 3,800 mg/L.
A. 180 mL/g
B. 121 mL/g
C. 87 mL/g
D. 94 mL/g 121 mL/g
How many gallons/day of primary sludge is collected at the bottom of a primary clarifier if the
influent to the clarifier has a flow rate of 2.1 MGD and a TSS concentration of 250 MG/L. The
effluent from the clarifier has a TSS concentration of 125 MG/L, while the primary sludge is
4.5% solids by weight.
A. 6,892.4 gallons/day
B. 8,241.1 gallons/day
C. 5,833.3 gallons/day
D. 2,597.5 gallons/day Idk look answer up
What is the methane content in a properly operating anaerobic digester? 65 to 70% by
volume
What will the addition of chlorine gas do to the pH of wastewater? Decrease the pH
What is the purpose of a Parshall flume? Measure Flowrate
What is the typical removal efficiency of settable solids in a primary clarifier? 95 to 99%
Pumping scum from a primary clarifier can cause more piping problems than other substances
pumped at a wastewater treatment plant? TRUE.
What might cause thick billows of white sudsy foam in the aeration tank? MLSS is too low
,What does the "M" in F/M ratio represent? The mixed liquor volatile suspended solids in the
aeration tank.
In general, how will warmer temperature affect the settling rate of solids in a clarifier? It
increases the settling rate
What could happen if the digester gas is mixed with air (85 to 95% by volume)? Cause an
explosion
How will algae impact the chlorine demand in the pond effluent? It increase the chlorine
demand
TRUE OR FALSE: A positive displacement pump must NEVER be started with the discharge valve
closed. TRUE
TRUE OR FALSE: The volume of a secondary clarifier is not needed to determine the F/M ratio?
TRUE
Which of the following is one of the basic rules of lab work?
a. Do not leave keys in equipment or vehicles at any time.
b. Patrol the facilities frequently, and look for suspicious activity or behavior.
c. Never Pipet hazardous material with your mouth, even if the pipet has been sterilized.
d. Lock Out and Tag out relevant mechanical and electrical equipment before staring any
maintenance activity. C
What is the recirculation ration for a trickling filter?
A. Qr/Q
B. Q/Qr
, C. Q/Qr+Q
D.Qr+Q/Q A
Which of the following is true about COD and BOD?
A. They are direct measurements of organic content in the influent.
B. They measure the inorganic content of the influent
C. They represent the amount of filamentous bacteria in the influent
D. They are indirect measurements of the organic content in the influent. D
What is the purpose of the grit channel?
A. Remove dissolved and non-settable organics
B. Remove heavy inorganic wastes
C. To allow activated sludge to settle
D. Remove substances that float and readily settle from the wastewater as primary treatment.
B
Which of the following is true about the extended aeration process?
A. Bugs get more food
B. Wasting is not necessary
C. It does not produce as much waste sludge as the other process
D. It is very different from the conventional activated sludge process. C
What is the correct formula for solids in wastewater?
A. Non-volatile solids +Suspended solids = Total solids in the influent
B. Dissolved Solids + Settable Solids = Total Suspended Solids
C. Colloids + Dissolved Solids = Total Suspended Solids
D. Non-settable solids + Settable Solids = Total Suspended solids D
