5/29/25, 10:50 PM Colorado WW Operator D Exam ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+ GRADED 100% VERIF…
Colorado WW Operator D Exam ACTUAL EXAM
QUESTIONS WITH COMPLETE SOLUTION GUIDE
(A+ GRADED 100% VERIFIED) LATEST VERSION
2025!!
Save
Terms in this set (425)
______ = BOD, lbs/day / F/M ratio
MLVSS, lbs
In a conventional At the head end of the tank
activated sludge plant,
oxygen demand is highest
BOD and the desired removal efficiency, Volatile
Air requirements in an
suspended solids concentration in the aerator,
activated sludge tank are
Suspended solids concentrations of the primary
governed by
effluent
It is not necessary to be a Filamentous bacteria, rotifers, protozoa
skilled microbiologist or to
be able to identify or
count individual species.
Rather the operator needs
only to recognize major
groups of organisms such
as:
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 1/63
,5/29/25, 10:50 PM Colorado WW Operator D Exam ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+ GRADED 100% VERIF…
In addition to high energy Damage to floc particles due to turbulence
costs, excess DO levels
can cause
Which of the following are MCRT, Alkalinity and pH, Temperature, DO, TKN
key factors in activated loading
sludge nitrification? Check
all that apply.
An activated sludge that Bulking
settles poorly and has an
SVI > 250 mL/g is
described as what?
Which of the following is a All of these answers are correct
modification of the
activated sludge process?
Taking samples at different Proper mixing in the tank
locations along the length
and the width of a reactor
(aeration tank) as well as at
different depths and
analyzing them for solids
concentration will verify
whether or not you
have....?
CCSS stands for: Clarifier core suspended solids
Because nitrifiers grow 5 days
slower than other
bacteria, sludge ages
longer than ____ days are
often needed.
During plant rounds, an Check the dissolved oxygen level in the aeration tank
operator notices that the
secondary effluent is
cloudy. The operator
should:
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 2/63
,5/29/25, 10:50 PM Colorado WW Operator D Exam ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+ GRADED 100% VERIF…
Given the following data, 11,467 lb
determine the excess
solids (in lbs) that should
be wasted from this
activated sludge system.
Target F:M = 0.6 per day,
MLVSS = 2500 mg/L, BOD
loading= 18,140 lb/day,
Volume of aeration basin =
2 million gallons
Conditions in which Anoxic
oxygen is absent but
nitrate is present are
referred to as what?
What characteristics are Brown color, some dissolved oxygen content, and
associated with quality good settling
activated sludge?
The activated sludge Absorption
process removes soluble
BOD from wastewater by
Why is the sludge To provide microorganisms
returned from the
secondary clarifier to the
aeration tank in activated
sludge used for
nitrification?
If fine-bubble diffusers are Mildly agitated, partially covered with light foam
used to introduce air into
a biological reactor, the
surface of the tank will
typically have what type
of appearance?
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 3/63
, 5/29/25, 10:50 PM Colorado WW Operator D Exam ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+ GRADED 100% VERIF…
In an anoxic activated Nitrate, NO3
sludge process, oxygen
for facultative bacteria is
provided by...?
A small area of dark The introduction of a septic sidestream
gray/black sludge in an
aeration tank can be due
to aeration equipment
failure or ____.
When doing a 30-minute FALSE
activated sludge
settleability test, a 1000ml
Imhoff cone should be
used.
In a conventional 0.8 to 1.2 lb oxygen /lb BOD
activated sludge process,
how much oxygen is
required per lb. of BOD
removed?
Which of the following Clarifier hydraulic loading
conditions would least
likely contribute to rising
sludge in secondary
clarifiers?
In an activated sludge Enzymes
process bacteria release
chemicals called ________
that break down the food
particles that are
adsorbed to the cell wall
so that they can be
absorbed by the
microorganism.
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 4/63
Colorado WW Operator D Exam ACTUAL EXAM
QUESTIONS WITH COMPLETE SOLUTION GUIDE
(A+ GRADED 100% VERIFIED) LATEST VERSION
2025!!
Save
Terms in this set (425)
______ = BOD, lbs/day / F/M ratio
MLVSS, lbs
In a conventional At the head end of the tank
activated sludge plant,
oxygen demand is highest
BOD and the desired removal efficiency, Volatile
Air requirements in an
suspended solids concentration in the aerator,
activated sludge tank are
Suspended solids concentrations of the primary
governed by
effluent
It is not necessary to be a Filamentous bacteria, rotifers, protozoa
skilled microbiologist or to
be able to identify or
count individual species.
Rather the operator needs
only to recognize major
groups of organisms such
as:
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 1/63
,5/29/25, 10:50 PM Colorado WW Operator D Exam ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+ GRADED 100% VERIF…
In addition to high energy Damage to floc particles due to turbulence
costs, excess DO levels
can cause
Which of the following are MCRT, Alkalinity and pH, Temperature, DO, TKN
key factors in activated loading
sludge nitrification? Check
all that apply.
An activated sludge that Bulking
settles poorly and has an
SVI > 250 mL/g is
described as what?
Which of the following is a All of these answers are correct
modification of the
activated sludge process?
Taking samples at different Proper mixing in the tank
locations along the length
and the width of a reactor
(aeration tank) as well as at
different depths and
analyzing them for solids
concentration will verify
whether or not you
have....?
CCSS stands for: Clarifier core suspended solids
Because nitrifiers grow 5 days
slower than other
bacteria, sludge ages
longer than ____ days are
often needed.
During plant rounds, an Check the dissolved oxygen level in the aeration tank
operator notices that the
secondary effluent is
cloudy. The operator
should:
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 2/63
,5/29/25, 10:50 PM Colorado WW Operator D Exam ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+ GRADED 100% VERIF…
Given the following data, 11,467 lb
determine the excess
solids (in lbs) that should
be wasted from this
activated sludge system.
Target F:M = 0.6 per day,
MLVSS = 2500 mg/L, BOD
loading= 18,140 lb/day,
Volume of aeration basin =
2 million gallons
Conditions in which Anoxic
oxygen is absent but
nitrate is present are
referred to as what?
What characteristics are Brown color, some dissolved oxygen content, and
associated with quality good settling
activated sludge?
The activated sludge Absorption
process removes soluble
BOD from wastewater by
Why is the sludge To provide microorganisms
returned from the
secondary clarifier to the
aeration tank in activated
sludge used for
nitrification?
If fine-bubble diffusers are Mildly agitated, partially covered with light foam
used to introduce air into
a biological reactor, the
surface of the tank will
typically have what type
of appearance?
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 3/63
, 5/29/25, 10:50 PM Colorado WW Operator D Exam ACTUAL EXAM QUESTIONS WITH COMPLETE SOLUTION GUIDE (A+ GRADED 100% VERIF…
In an anoxic activated Nitrate, NO3
sludge process, oxygen
for facultative bacteria is
provided by...?
A small area of dark The introduction of a septic sidestream
gray/black sludge in an
aeration tank can be due
to aeration equipment
failure or ____.
When doing a 30-minute FALSE
activated sludge
settleability test, a 1000ml
Imhoff cone should be
used.
In a conventional 0.8 to 1.2 lb oxygen /lb BOD
activated sludge process,
how much oxygen is
required per lb. of BOD
removed?
Which of the following Clarifier hydraulic loading
conditions would least
likely contribute to rising
sludge in secondary
clarifiers?
In an activated sludge Enzymes
process bacteria release
chemicals called ________
that break down the food
particles that are
adsorbed to the cell wall
so that they can be
absorbed by the
microorganism.
https://quizlet.com/1049524123/colorado-ww-operator-d-exam-actual-exam-questions-with-complete-solution-guide-a-graded-100-verified-latest-versi… 4/63
