Colorado WW Operator D Exam ACTUAL EXAM
QUESTIONS WITH COMPLETE SOLUTION GUIDE A+
|GRADED 100% VERIFIED| LATEST VERSION
(2026/2027)!!
______ = BOD, lbs/day / MLVSS, lbs - ANSWER--F/M
ratio
In a conventional activated sludge plant, oxygen demand
is highest - ANSWER--At the head end of the tank
Air requirements in an activated sludge tank are governed
by - ANSWER--BOD and the desired removal efficiency,
,Volatile suspended solids concentration in the aerator,
Suspended solids concentrations of the primary effluent
It is not necessary to be a 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: - ANSWER--Filamentous bacteria,
rotifers, protozoa
In addition to high energy costs, excess DO levels can
cause - ANSWER--Damage to floc particles due to
turbulence
,Which of the following are key factors in activated sludge
nitrification? Check all that apply. - ANSWER--MCRT,
Alkalinity and pH, Temperature, DO, TKN loading
Taking samples at different 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....? - ANSWER--Proper
mixing in the tank
CCSS stands for: - ANSWER--Clarifier core suspended
solids
, Because nitrifiers grow slower than other bacteria, sludge
ages longer than ____ days are often needed. -
ANSWER--5 days
During plant rounds, an operator notices that the
secondary effluent is cloudy. The operator should: -
ANSWER--Check the dissolved oxygen level in the
aeration tank
Given the following data, 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 - ANSWER--11,467 lb
QUESTIONS WITH COMPLETE SOLUTION GUIDE A+
|GRADED 100% VERIFIED| LATEST VERSION
(2026/2027)!!
______ = BOD, lbs/day / MLVSS, lbs - ANSWER--F/M
ratio
In a conventional activated sludge plant, oxygen demand
is highest - ANSWER--At the head end of the tank
Air requirements in an activated sludge tank are governed
by - ANSWER--BOD and the desired removal efficiency,
,Volatile suspended solids concentration in the aerator,
Suspended solids concentrations of the primary effluent
It is not necessary to be a 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: - ANSWER--Filamentous bacteria,
rotifers, protozoa
In addition to high energy costs, excess DO levels can
cause - ANSWER--Damage to floc particles due to
turbulence
,Which of the following are key factors in activated sludge
nitrification? Check all that apply. - ANSWER--MCRT,
Alkalinity and pH, Temperature, DO, TKN loading
Taking samples at different 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....? - ANSWER--Proper
mixing in the tank
CCSS stands for: - ANSWER--Clarifier core suspended
solids
, Because nitrifiers grow slower than other bacteria, sludge
ages longer than ____ days are often needed. -
ANSWER--5 days
During plant rounds, an operator notices that the
secondary effluent is cloudy. The operator should: -
ANSWER--Check the dissolved oxygen level in the
aeration tank
Given the following data, 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 - ANSWER--11,467 lb
