WASTEWATER TREATMENT
OPERATOR EXAM PREP QUESTIONS
ANSWERS EXPERT VERIFIED
◉ What does the "F" in F/M ratio represent?
A) The microorganism population in the aeration tank
B) The amount of filamentous bacteria in the activated sludge
process
C) The MLVSS in the aeration tank
D) The food for the microorganisms flowing into the aeration tank,
in lbs/day. Answer: D) The food for the microorganisms flowing into
the aeration tank, in lbs/day (v.2 pg 58)
◉ Which of the following describes the appearance of healthy
activated sludge?
A) Thick, greasy, dark tan foam
B) Brown with a moderate amount of crisp, white foam
C) Clear liquid with clear foam
D) Gray liquid with no foam. Answer: B) Brown with a moderate
amount of crisp, white foam
,◉ What is used to control filamentous organisms?
A) Polymer
B) Sulfur Dioxide
C) Coagulant
D) Chlorine. Answer: D) Chlorine (v.1 pg 399)
◉ What are commonly used to control chlorine feed rate for
disinfection?
A) BOD and MLVSS
B) pH and temperature
C) Flow and chlorine residual
D) DO and TSS. Answer: C) Flow and chlorine residual (v.1 pg 356)
◉ Which toxic gas is commonly found in septic wastewater and
smells like rotten eggs?
A) Hydrogen Sulfide
B) Carbon monoxide
C) Hydrogen
,D) Carbon Dioxide. Answer: A) Hydrogen Sulfide (v.2 pg 299)
◉ What is the permissible exposure limit for chlorine gas vapor
during a normal 8 hour workday and a 40 hour work week?
A) 0.1 ppm
B) 0.5 ppm
C) 1 ppm
D) 15 ppm. Answer: B) 0.5 ppm (v.2 pg 268)
◉ What is a vulnerability assessment?
A) Assesses the impact of hydrogen sulfide to a concrete structure
B) Analyzes the impact of flow and infiltration problem to the plant
hydraulics
C) Estimates the vulnerability of aquatic wildlife to excessive algae
growth
D) Contingency planning to determine the vulnerability of the utility
during various types of emergencies and identify corrective actions
to reduce the risks. Answer: D) Contingency planning to determine
the vulnerability of the utility during various types of emergencies
and identify corrective actions to reduce the risks (v.2 pg 722)
, ◉ What is the difference between the settling rate of activated
sludge and raw sludge?
A) Activated sludge settles slightly faster than raw sludge
B) Activated sludge settles at the same rate as raw sludge
C) Activated sludge settles slower than raw sludge
D) Activated sludge settles much faster than raw sludge. Answer: C)
Activated sludge settles slower than raw sludge (v.1 pg 109)
◉ What should be mostly found in healthy activated sludge?
A) Tiny flagellates
B) Amoeboids
C) Short Filaments
D) Free swimmers and stalked ciliates. Answer: D) Free swimmers
and stalked ciliates (v.2 pg 120,124)
◉ One to two percent of the digester gas in an anaerobic consists of
A) Hydrogen, Nitrogen, Hydrogen sulfide, and other gases
B) Methane
C) Carbon Dioxide
OPERATOR EXAM PREP QUESTIONS
ANSWERS EXPERT VERIFIED
◉ What does the "F" in F/M ratio represent?
A) The microorganism population in the aeration tank
B) The amount of filamentous bacteria in the activated sludge
process
C) The MLVSS in the aeration tank
D) The food for the microorganisms flowing into the aeration tank,
in lbs/day. Answer: D) The food for the microorganisms flowing into
the aeration tank, in lbs/day (v.2 pg 58)
◉ Which of the following describes the appearance of healthy
activated sludge?
A) Thick, greasy, dark tan foam
B) Brown with a moderate amount of crisp, white foam
C) Clear liquid with clear foam
D) Gray liquid with no foam. Answer: B) Brown with a moderate
amount of crisp, white foam
,◉ What is used to control filamentous organisms?
A) Polymer
B) Sulfur Dioxide
C) Coagulant
D) Chlorine. Answer: D) Chlorine (v.1 pg 399)
◉ What are commonly used to control chlorine feed rate for
disinfection?
A) BOD and MLVSS
B) pH and temperature
C) Flow and chlorine residual
D) DO and TSS. Answer: C) Flow and chlorine residual (v.1 pg 356)
◉ Which toxic gas is commonly found in septic wastewater and
smells like rotten eggs?
A) Hydrogen Sulfide
B) Carbon monoxide
C) Hydrogen
,D) Carbon Dioxide. Answer: A) Hydrogen Sulfide (v.2 pg 299)
◉ What is the permissible exposure limit for chlorine gas vapor
during a normal 8 hour workday and a 40 hour work week?
A) 0.1 ppm
B) 0.5 ppm
C) 1 ppm
D) 15 ppm. Answer: B) 0.5 ppm (v.2 pg 268)
◉ What is a vulnerability assessment?
A) Assesses the impact of hydrogen sulfide to a concrete structure
B) Analyzes the impact of flow and infiltration problem to the plant
hydraulics
C) Estimates the vulnerability of aquatic wildlife to excessive algae
growth
D) Contingency planning to determine the vulnerability of the utility
during various types of emergencies and identify corrective actions
to reduce the risks. Answer: D) Contingency planning to determine
the vulnerability of the utility during various types of emergencies
and identify corrective actions to reduce the risks (v.2 pg 722)
, ◉ What is the difference between the settling rate of activated
sludge and raw sludge?
A) Activated sludge settles slightly faster than raw sludge
B) Activated sludge settles at the same rate as raw sludge
C) Activated sludge settles slower than raw sludge
D) Activated sludge settles much faster than raw sludge. Answer: C)
Activated sludge settles slower than raw sludge (v.1 pg 109)
◉ What should be mostly found in healthy activated sludge?
A) Tiny flagellates
B) Amoeboids
C) Short Filaments
D) Free swimmers and stalked ciliates. Answer: D) Free swimmers
and stalked ciliates (v.2 pg 120,124)
◉ One to two percent of the digester gas in an anaerobic consists of
A) Hydrogen, Nitrogen, Hydrogen sulfide, and other gases
B) Methane
C) Carbon Dioxide
