WASTEWATER TREATMENT OPERATOR
Certification Final Exam Questions and Answers
with Rationales Latest Versions 2025 Top Rated
A+
Which of the following will not affect the settling characteristics in a clarifier?
A) Temperature
B) Short Circuit
C) Detention Time
D) Depth of launder - ANSWER-D) Depth of launder (v.1 pg 134-135)
The best way to evaluate the effluent TSS concentration from a plant is to
A) Check the grab sample at peak flow
B) Check the composite sample of TSS
C) Check the grab sample at low flow
D) Check the grab sample during average flow - ANSWER-B) Check the composite sample of TSS (v.1 pg
128)
Which of the following is not associated with an aeration tank?
A) RAS
B) WAS
C) RBC
D) MCRT - ANSWER-C) RBC (v.2 pg 56,59)
What creates hydrogen sulfide?
A) Excessive aeration
,B) Surface active agents
C) Organic matter under aerobic condition
D) Decomposing organic matter under anaerobic condition - ANSWER-D) Decomposing organic matter
under anaerobic condition (v.2 pg 299)
A pond with a detention time of less than three days will perform similar to
A) Sedimentation tank
B) Aeration tank
C) Trickling Filter
D) RBC - ANSWER-A) Sedimentation tank (v.1 pg 299)
Which type of Bacteria is used for a Trickling Filter?
A) Anaerobic bacteria
B) Anoxic bacteria
C) Aerobic bacteria
D) Facultative bacteria - ANSWER-C) Aerobic bacteria (v.1 pg 46)
Which of the following is not associated with a trickling filter?
A) Media
B) Filamentous bacteria
C) Zoogleal Film
D) Recirculation - ANSWER-B) Filamentous bacteria (v.1 pg 169)
What is an MCRT?
A) A calculation that indicates the tendency of activated sludge solids to thicken
B) A measure of food provided to bacteria in an aeration tank.
C) The amount of volatile suspended solids in the mixed liquor of an aeration tank
D) An expression of the average time a microorganism will spend in an activated sludge process. -
ANSWER-D) An expression of the average time a microorganism will spend in an activated sludge
process. (v.2 pg 59)
, What is the methane content in a properly operation anaerobic digester?
Certification Final Exam Questions and Answers
with Rationales Latest Versions 2025 Top Rated
A+
Which of the following will not affect the settling characteristics in a clarifier?
A) Temperature
B) Short Circuit
C) Detention Time
D) Depth of launder - ANSWER-D) Depth of launder (v.1 pg 134-135)
The best way to evaluate the effluent TSS concentration from a plant is to
A) Check the grab sample at peak flow
B) Check the composite sample of TSS
C) Check the grab sample at low flow
D) Check the grab sample during average flow - ANSWER-B) Check the composite sample of TSS (v.1 pg
128)
Which of the following is not associated with an aeration tank?
A) RAS
B) WAS
C) RBC
D) MCRT - ANSWER-C) RBC (v.2 pg 56,59)
What creates hydrogen sulfide?
A) Excessive aeration
,B) Surface active agents
C) Organic matter under aerobic condition
D) Decomposing organic matter under anaerobic condition - ANSWER-D) Decomposing organic matter
under anaerobic condition (v.2 pg 299)
A pond with a detention time of less than three days will perform similar to
A) Sedimentation tank
B) Aeration tank
C) Trickling Filter
D) RBC - ANSWER-A) Sedimentation tank (v.1 pg 299)
Which type of Bacteria is used for a Trickling Filter?
A) Anaerobic bacteria
B) Anoxic bacteria
C) Aerobic bacteria
D) Facultative bacteria - ANSWER-C) Aerobic bacteria (v.1 pg 46)
Which of the following is not associated with a trickling filter?
A) Media
B) Filamentous bacteria
C) Zoogleal Film
D) Recirculation - ANSWER-B) Filamentous bacteria (v.1 pg 169)
What is an MCRT?
A) A calculation that indicates the tendency of activated sludge solids to thicken
B) A measure of food provided to bacteria in an aeration tank.
C) The amount of volatile suspended solids in the mixed liquor of an aeration tank
D) An expression of the average time a microorganism will spend in an activated sludge process. -
ANSWER-D) An expression of the average time a microorganism will spend in an activated sludge
process. (v.2 pg 59)
, What is the methane content in a properly operation anaerobic digester?
