WASTEWATER TREATMENT
OPERATOR ACTUAL EXAM
COMPLETE QUESTIONS 100
PERCENT CORRECT
◉ What type of sludge would you expect in an aeration tank if the
content is dark and has low DO?
A) Sludge that is heavy
B) Chlorinated Sludge
C) Septic Sludge
D) Healthy Sludge. Answer: C) Septic Sludge (v.2 pg 75)
◉ What could have happen if the volatile acid/alkalinity ratio starts
to increase, and corrective action is not taken immediately?
A) Carbon dioxide content in the digester gas will decrease
B) Carbon monoxide content in the digester gas will fluctuate
C) pH of the digester sludge will increase
D) Carbon dioxide content in the digester gas will increase. Answer:
D) Carbon dioxide content in the digester gas will increase (v.2 pg
191)
,◉ What are screenings?
A) Colloids
B) TDS
C) Pieces of wood, roots, rags, and other large debris
D) COD. Answer: C) Pieces of wood, roots, rags, and other large
debris (v.1 pg 41)
◉ What happens when there is more food in the influent to the
aeration tank?
A) Less oxygen is required in the aeration tank
B) More oxygen is required in the aeration tank
C) Less organism activity takes place
D) Less oxidation takes place. Answer: B) More oxygen is required in
the aeration tank (v.2 pg 19)
◉ What impact does temperature have on the reaction rate of
microorganisms in wastewater?
A) Reaction rate doubles with every 18 degree Fahrenheit increase
in temperature until higher temperature inhibits biological activity
, B) Reaction rate decreases by 20% with every 10 degree Fahrenheit
increase in temperature
C) Reaction rate of microorganism is not impacted by temperature
D) Reaction rate goes to zero. Answer: A) Reaction rate doubles with
every 18 degree Fahrenheit increase in temperature until higher
◉ What is commonly used to control the odor of hydrogen sulfide?
A) Carbon Dioxide
B) Methane
C) Chlorine
D) Hydrogen. Answer: C) Chlorine (v.1 pg 398)
◉ What is used to determine the amount of microorganisms in the
aeration tank?
A) Mixed Liquor Suspended Solids (MLSS)
B) Influent TSS
C) BOD
D) Mixed Liquor Volatile Suspended Solids (MLVSS). Answer: D)
Mixed Liquor Volatile Suspended Solids (MLVSS) (v.2 pg 58)
OPERATOR ACTUAL EXAM
COMPLETE QUESTIONS 100
PERCENT CORRECT
◉ What type of sludge would you expect in an aeration tank if the
content is dark and has low DO?
A) Sludge that is heavy
B) Chlorinated Sludge
C) Septic Sludge
D) Healthy Sludge. Answer: C) Septic Sludge (v.2 pg 75)
◉ What could have happen if the volatile acid/alkalinity ratio starts
to increase, and corrective action is not taken immediately?
A) Carbon dioxide content in the digester gas will decrease
B) Carbon monoxide content in the digester gas will fluctuate
C) pH of the digester sludge will increase
D) Carbon dioxide content in the digester gas will increase. Answer:
D) Carbon dioxide content in the digester gas will increase (v.2 pg
191)
,◉ What are screenings?
A) Colloids
B) TDS
C) Pieces of wood, roots, rags, and other large debris
D) COD. Answer: C) Pieces of wood, roots, rags, and other large
debris (v.1 pg 41)
◉ What happens when there is more food in the influent to the
aeration tank?
A) Less oxygen is required in the aeration tank
B) More oxygen is required in the aeration tank
C) Less organism activity takes place
D) Less oxidation takes place. Answer: B) More oxygen is required in
the aeration tank (v.2 pg 19)
◉ What impact does temperature have on the reaction rate of
microorganisms in wastewater?
A) Reaction rate doubles with every 18 degree Fahrenheit increase
in temperature until higher temperature inhibits biological activity
, B) Reaction rate decreases by 20% with every 10 degree Fahrenheit
increase in temperature
C) Reaction rate of microorganism is not impacted by temperature
D) Reaction rate goes to zero. Answer: A) Reaction rate doubles with
every 18 degree Fahrenheit increase in temperature until higher
◉ What is commonly used to control the odor of hydrogen sulfide?
A) Carbon Dioxide
B) Methane
C) Chlorine
D) Hydrogen. Answer: C) Chlorine (v.1 pg 398)
◉ What is used to determine the amount of microorganisms in the
aeration tank?
A) Mixed Liquor Suspended Solids (MLSS)
B) Influent TSS
C) BOD
D) Mixed Liquor Volatile Suspended Solids (MLVSS). Answer: D)
Mixed Liquor Volatile Suspended Solids (MLVSS) (v.2 pg 58)
