wastewater grade 2 exam verified with correct answers 2026/2027
version
which of the following is one of the basic rules of laboratory work?- answer>>>
>>>never pipet hazardous material with your mouth, even if the pipet has been
sterilized
what is the purpose of the grit channel?- answer>>> >>>Remove heavy inorganic
wastes
what is the correct formula for solids in raw wastewater?- answer>>> >>>non-settleable
solids + settleable solids = total suspended solids
What is freeboard in a waste stabilization pond?- answer>>> >>>the vertical distance
from normal water surface to the top of the levee
prior to entering a permit-required confined space, what should you verify?- answer>>>
>>>a standby person should be located outside the entrance to the confined space,
while another person should be within sight or call of the standby person.
what is a common way to determine the organic strength of wastes in the influent?-
answer>>> >>>test for the biochemical oxygen demand
what should you do if you are mildly exposed to chlorine gas?- answer>>>
>>>immediately evacuate the contaminated area, remain clam, keep warm, breathe
lightly, and avoid coughing
what are the main sources of domestic sewage in the collection system?- answer>>>
>>>households and commercial establishments
what are mostly removed in the grit channel?- answer>>> >>>sand, eggshells, cinders,
and heavier particulate matter
which gas diminished your sense of smell?- answer>>> >>>hydrogen sulfide
which of the following enters the headworks of a treatment plant?- answer>>>
>>>influent
what is the equivalent of 1 mg/L?- answer>>> >>>1 ppm
what is equivalent to organic solids?- answer>>> >>>volatile solids
what should be done if a largge amount of organic matter is found in the grit channel?-
answer>>> >>>increase the velocity of wastewater
, what is the difference between the sludge from a primary clarifier and secondary
clarifier?- answer>>> >>>primary sludge is denser than secondary sludge
which process includes a blower?- answer>>> >>>activated sludge
how does an activated sludge system remove waste from wastewater?- answer>>>
>>>biological treatment
which of the following best describes per-chlorination?- answer>>> >>>addition of
chlorine to wastewater at the entrance to the plant, and 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?- answer>>> >>>fall and winter, when the weather is cool and sunlight is reduced
what is the first steps of lockout/tagout procedure?- answer>>> >>>notify all affected
employees that a lockout or tagged system is going to be used and the reason why
what type of process is the activated sludge system?- answer>>> >>>aerobic
what might cause sludge to rise in a clarifier?- answer>>> >>>gasification from aging
sludge
the temperature of the plant influent is:- answer>>> >>>slightly warmer than tap water
the purpose of disinfection is to:- answer>>> >>>destruction or inactivation of
pathogenic bacteria
what must you do before entering a room with harmful concentration of chlorine gas in
the air?- answer>>> >>>wear self-contained breathing apparatus (SCBA)
what does black sludge at the bottom of a secondary clarifier located downstream of a
trickling filter signify?- answer>>> >>>sludge has stayed in the secondary clarifier to
long
which of the following is true about algae in a pond?- answer>>> >>>during the
daytime, the algae will release oxygen for the aerobic bacteria in the pond
the effectiveness of disinfection is determined by:- answer>>> >>>the coliform
concentration in the effluent
how often should the sludge at the bottom of a clarifier be pumped?- answer>>>
>>>frequently throughout the day
which of the following is not associated with an aeration tank?- answer>>> >>>RBC
version
which of the following is one of the basic rules of laboratory work?- answer>>>
>>>never pipet hazardous material with your mouth, even if the pipet has been
sterilized
what is the purpose of the grit channel?- answer>>> >>>Remove heavy inorganic
wastes
what is the correct formula for solids in raw wastewater?- answer>>> >>>non-settleable
solids + settleable solids = total suspended solids
What is freeboard in a waste stabilization pond?- answer>>> >>>the vertical distance
from normal water surface to the top of the levee
prior to entering a permit-required confined space, what should you verify?- answer>>>
>>>a standby person should be located outside the entrance to the confined space,
while another person should be within sight or call of the standby person.
what is a common way to determine the organic strength of wastes in the influent?-
answer>>> >>>test for the biochemical oxygen demand
what should you do if you are mildly exposed to chlorine gas?- answer>>>
>>>immediately evacuate the contaminated area, remain clam, keep warm, breathe
lightly, and avoid coughing
what are the main sources of domestic sewage in the collection system?- answer>>>
>>>households and commercial establishments
what are mostly removed in the grit channel?- answer>>> >>>sand, eggshells, cinders,
and heavier particulate matter
which gas diminished your sense of smell?- answer>>> >>>hydrogen sulfide
which of the following enters the headworks of a treatment plant?- answer>>>
>>>influent
what is the equivalent of 1 mg/L?- answer>>> >>>1 ppm
what is equivalent to organic solids?- answer>>> >>>volatile solids
what should be done if a largge amount of organic matter is found in the grit channel?-
answer>>> >>>increase the velocity of wastewater
, what is the difference between the sludge from a primary clarifier and secondary
clarifier?- answer>>> >>>primary sludge is denser than secondary sludge
which process includes a blower?- answer>>> >>>activated sludge
how does an activated sludge system remove waste from wastewater?- answer>>>
>>>biological treatment
which of the following best describes per-chlorination?- answer>>> >>>addition of
chlorine to wastewater at the entrance to the plant, and 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?- answer>>> >>>fall and winter, when the weather is cool and sunlight is reduced
what is the first steps of lockout/tagout procedure?- answer>>> >>>notify all affected
employees that a lockout or tagged system is going to be used and the reason why
what type of process is the activated sludge system?- answer>>> >>>aerobic
what might cause sludge to rise in a clarifier?- answer>>> >>>gasification from aging
sludge
the temperature of the plant influent is:- answer>>> >>>slightly warmer than tap water
the purpose of disinfection is to:- answer>>> >>>destruction or inactivation of
pathogenic bacteria
what must you do before entering a room with harmful concentration of chlorine gas in
the air?- answer>>> >>>wear self-contained breathing apparatus (SCBA)
what does black sludge at the bottom of a secondary clarifier located downstream of a
trickling filter signify?- answer>>> >>>sludge has stayed in the secondary clarifier to
long
which of the following is true about algae in a pond?- answer>>> >>>during the
daytime, the algae will release oxygen for the aerobic bacteria in the pond
the effectiveness of disinfection is determined by:- answer>>> >>>the coliform
concentration in the effluent
how often should the sludge at the bottom of a clarifier be pumped?- answer>>>
>>>frequently throughout the day
which of the following is not associated with an aeration tank?- answer>>> >>>RBC
