Ca Grade 2 Wastewater Treatment Operator Practice Exam 1 Questions with Verified
Answers| Latest Update Graded A+
Which of the following best describes pre-chlorination? addition of chlorine to wastewater
at the entrance to the plant used for odor control, BOD reduction, grease removal, and aid
sedimentation
When would you expect reduced algae population and less oxygen released into a pond? fall
and winter, when the weather is cool and sunlight is reduced
What is the first step of the lockout/tagout procedure? notify all affected employees that a
lockout/tagout system is going to be used and the reason why
What type of process is the activated sludge system? aerobic
What will happen if too much raw sludge is added to the digester? acid fermenters will
predominate and lower the pH
What might cause sludge to rise in a clarifier? gasification from aging sludge
What happens when carbon dioxide is removed from a pond? increases pH
How much dissolved oxygen should be in a conventional activated sludge system if good
effluent is being produced? 2 to 4 mg/l
What is the typical concentration of mixed liquor suspended solids in a conventional activated
sludge process? 1000 to 4500 mg/l
The temperature of the plant influent is? slighty warmer than tap water
, The purpose of disinfection is to? destruction or inactivation of pathogenic bacteria
What must you do before entering a room with harmful concentration of chlorine gas in the
air? wear self contained breathing apparatus(scba)
What does black sludge at the bottom of a secondary clarifier located downstream of a trickling
filter signify? sludge has stayed in the secondary clarifier too long
If the lab results show that the plant influent sample has COD of 100 mg/l and a BOD of 300
mg/l, which of the following is most likey true? lab results appear incorrect
If a primary clarifier is placed out of service, then how should a plant with at least 2 trickling
filters operate the system? operate the filters in series
What is the main reason for preventing a direct connection between a potable water pipe and a
stuffing box(packings) of a wastewater pump? cross connection
Which of the following is true about algae in a pond? during the day time the algae will
release oxygen for the aerobic bacteria in the pond
Which of the following is not true about hydrogen sulfide? hydrogen sulfide is lighter than
air
What type of treatment is primarily used to thicken sludge instead of dewater the sludge?
DAF Dissolved Air Flotation
Why should sludge at the bottom of a clarifier be removed in a timely manner? to prevent
sludge gasification which causes the sludge to float
Answers| Latest Update Graded A+
Which of the following best describes pre-chlorination? addition of chlorine to wastewater
at the entrance to the plant used for odor control, BOD reduction, grease removal, and aid
sedimentation
When would you expect reduced algae population and less oxygen released into a pond? fall
and winter, when the weather is cool and sunlight is reduced
What is the first step of the lockout/tagout procedure? notify all affected employees that a
lockout/tagout system is going to be used and the reason why
What type of process is the activated sludge system? aerobic
What will happen if too much raw sludge is added to the digester? acid fermenters will
predominate and lower the pH
What might cause sludge to rise in a clarifier? gasification from aging sludge
What happens when carbon dioxide is removed from a pond? increases pH
How much dissolved oxygen should be in a conventional activated sludge system if good
effluent is being produced? 2 to 4 mg/l
What is the typical concentration of mixed liquor suspended solids in a conventional activated
sludge process? 1000 to 4500 mg/l
The temperature of the plant influent is? slighty warmer than tap water
, The purpose of disinfection is to? destruction or inactivation of pathogenic bacteria
What must you do before entering a room with harmful concentration of chlorine gas in the
air? wear self contained breathing apparatus(scba)
What does black sludge at the bottom of a secondary clarifier located downstream of a trickling
filter signify? sludge has stayed in the secondary clarifier too long
If the lab results show that the plant influent sample has COD of 100 mg/l and a BOD of 300
mg/l, which of the following is most likey true? lab results appear incorrect
If a primary clarifier is placed out of service, then how should a plant with at least 2 trickling
filters operate the system? operate the filters in series
What is the main reason for preventing a direct connection between a potable water pipe and a
stuffing box(packings) of a wastewater pump? cross connection
Which of the following is true about algae in a pond? during the day time the algae will
release oxygen for the aerobic bacteria in the pond
Which of the following is not true about hydrogen sulfide? hydrogen sulfide is lighter than
air
What type of treatment is primarily used to thicken sludge instead of dewater the sludge?
DAF Dissolved Air Flotation
Why should sludge at the bottom of a clarifier be removed in a timely manner? to prevent
sludge gasification which causes the sludge to float
