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Revision Examination Tests
“Come all for this Greatness”
... 100% Correct Ans ...
WASTEWATER TREATMENT CLASS 2 FINAL EXAM
QUESTIONS AND CORRECT DETAILED ANSWERS 2024-2025
A supervisor notices that solids exiting the dewatering facility has increased in
dryness by 1.2% after changing to a new cationic polymer. The next sample taken a
week later shows a reduction in dryness by 7%. Organic loadings have increased in
the plant while weather conditions have been unusually cold. What is the best
correct course of action to return the higher quality sludge?
Ans: Perform jar testing to estimate proper dosage of polymer while also adjusting
temperature of sludge
Quiz Which of the following is not considered a hazardous gas if exposed to over the
course of a shift?
-Diatomic oxygen
-Hydrogen sulfide
-Carbon dioxide
-Methane
Ans: Diatomic oxygen
Quiz You work at a plant that has a daily flow of 10.5 MGD. Currently organic loading
is normal. All clarifiers contain excessive floating sludge. Alkalinity has been steadily
decreasing over the last week and in the operator notes, there is mention of low pH
in the basins. What is occurring and what should be done to correct it?
Ans: Nitrification is consuming the alkalinity causing a drop in pH while solids are
being held too long in the clarifier causing denitrification
Quiz If all process control adjustments have been made to your DAFT, but solids are
escaping out to the effluent, what is the most likely cause?
Ans: The unit is overloaded and needs to be upgraded
Quiz Which has the least effect on the ability of water to contain sufficient DO?
Ans: Color
, Quiz What can be done to prevent the binding of a belt in a belt filter press?
Ans: Proper polymer dosage and regular cleaning
Quiz When pumping sludge to be wasted, what is the most important to consider?
Ans: Solids % from start to finish
Quiz Baffles in a contact chamber are primarily in place to increase detention time.
Which condition will prevent a long contact time from resulting in adequate
disinfection?
Ans: Reducing compounds such as nitrite and sulfites
Quiz A centrifugal pump that is operating against a closed discharge valve
temporarily will exhibit what?
Ans: Begin to heat up but will evaporate the water contained in the volute preventing
overheating
Quiz Which of the following would most likely indicate an anaerobic digester is
upset?
-Lack of a flame when attempting to burn
-68% methane
-Temperatures maintaining between 95-100 degrees F
Ans: Lack of a flame when attempting to burn
Quiz The purpose of a foot valve on a pump system is what?
Ans: To prevent the pump from losing prime
Quiz The bacteria responsible for nitrification are:
Ans: Nitrosomonas and nitrobacter
Quiz Which organisms are most responsible for the oxidation of dissolved organics
in wastewater?
Ans: Bacteria
Quiz Filamentous bacteria that may cause excessive foam, specifically nocardia, are
compounded by what conditions?
Ans: Low dissolved oxygen and high FOG in a warm environment
Quiz In an anoxic zone, which organisms will be most prevalent?
Ans: Facultative
Revision Examination Tests
“Come all for this Greatness”
... 100% Correct Ans ...
WASTEWATER TREATMENT CLASS 2 FINAL EXAM
QUESTIONS AND CORRECT DETAILED ANSWERS 2024-2025
A supervisor notices that solids exiting the dewatering facility has increased in
dryness by 1.2% after changing to a new cationic polymer. The next sample taken a
week later shows a reduction in dryness by 7%. Organic loadings have increased in
the plant while weather conditions have been unusually cold. What is the best
correct course of action to return the higher quality sludge?
Ans: Perform jar testing to estimate proper dosage of polymer while also adjusting
temperature of sludge
Quiz Which of the following is not considered a hazardous gas if exposed to over the
course of a shift?
-Diatomic oxygen
-Hydrogen sulfide
-Carbon dioxide
-Methane
Ans: Diatomic oxygen
Quiz You work at a plant that has a daily flow of 10.5 MGD. Currently organic loading
is normal. All clarifiers contain excessive floating sludge. Alkalinity has been steadily
decreasing over the last week and in the operator notes, there is mention of low pH
in the basins. What is occurring and what should be done to correct it?
Ans: Nitrification is consuming the alkalinity causing a drop in pH while solids are
being held too long in the clarifier causing denitrification
Quiz If all process control adjustments have been made to your DAFT, but solids are
escaping out to the effluent, what is the most likely cause?
Ans: The unit is overloaded and needs to be upgraded
Quiz Which has the least effect on the ability of water to contain sufficient DO?
Ans: Color
, Quiz What can be done to prevent the binding of a belt in a belt filter press?
Ans: Proper polymer dosage and regular cleaning
Quiz When pumping sludge to be wasted, what is the most important to consider?
Ans: Solids % from start to finish
Quiz Baffles in a contact chamber are primarily in place to increase detention time.
Which condition will prevent a long contact time from resulting in adequate
disinfection?
Ans: Reducing compounds such as nitrite and sulfites
Quiz A centrifugal pump that is operating against a closed discharge valve
temporarily will exhibit what?
Ans: Begin to heat up but will evaporate the water contained in the volute preventing
overheating
Quiz Which of the following would most likely indicate an anaerobic digester is
upset?
-Lack of a flame when attempting to burn
-68% methane
-Temperatures maintaining between 95-100 degrees F
Ans: Lack of a flame when attempting to burn
Quiz The purpose of a foot valve on a pump system is what?
Ans: To prevent the pump from losing prime
Quiz The bacteria responsible for nitrification are:
Ans: Nitrosomonas and nitrobacter
Quiz Which organisms are most responsible for the oxidation of dissolved organics
in wastewater?
Ans: Bacteria
Quiz Filamentous bacteria that may cause excessive foam, specifically nocardia, are
compounded by what conditions?
Ans: Low dissolved oxygen and high FOG in a warm environment
Quiz In an anoxic zone, which organisms will be most prevalent?
Ans: Facultative
