WASTEWATER CLASS B TEXAS COMPREHENSIVE EXAM
QUESTIONS AND ANSWERS GRADED A+
✔✔In the active sludge process, Utilization is the process where - ✔✔Food supply is
changed into a liquid state for use
✔✔In the activated sludge process, Stabilization is - ✔✔Wastes biologically converted
to water, carbon dioxide, or new cells
✔✔In the activated sludge process, the _______ is called the heart of the activated
sludge process. - ✔✔Clarifier
✔✔In the activated sludge process, factors that will influence the operation of the final
clarifier are - ✔✔Loading, solids applied, settling, thickness of solids, rate of return &
Wasting
✔✔In the activated sludge process, the clarifier will concentrate return sludge and waste
sludge about ___ to__ times the solids concentration of the mixed liquor - ✔✔two (2) to
four (4)
✔✔In the activated sludge process, for the clarifier to do its job, the ____ must be
retained long enough to allow ______ to settle and liquid to rise. - ✔✔water/ solids
✔✔In the activated sludge process, as more mixed liquor flows to the clarifier, the
thickness of the sludge blanket will - ✔✔Increase as solids accumulate
✔✔In the activated sludge process, biological solids from the bottom of the clarifier must
be returned to the aeration basin for re-seed. This process is accomplished by - ✔✔Air
lift pumps, centrifugal pumps, Diaphragm pumps, Screw pumps & Gravity Flow
✔✔In the activated sludge process, no sludge process will work properly without -
✔✔Regular removal of excess solids
✔✔In the activated sludge process, Mass Balance refers to - ✔✔Maintaining the
balance between Return Sludge Flow, Return Sludge, Aeration tank volume, Mixed
liquor suspended solids
✔✔In the activated sludge process, the terms F/M ratio is important because this refers
to - ✔✔Food to Microorganism Ratio
✔✔In the activated sludge process, the F/M Ratio is calculated by ______ the pounds
of _________ by the pounds of MLVSS in the ___________. - ✔✔Dividing/ Incoming
BOD/ aeration tank
, ✔✔In the activated sludge process, the term Gould Sludge Age refers to - ✔✔How long
in days a pound of solids stays in the aerator
✔✔In the activated sludge process, Gould Sludge Age (GSA) is calculated by -
✔✔Dividing the total pounds of TSS in the aerator by the pounds of TSS entering the
aerator as raw
✔✔In the activated sludge process, the term Mean Cell Residence Time (MCRT) refers
to - ✔✔The amount of time the living cells are kept in the plant
✔✔In the activated sludge process, daily observation of the aeration basin treatment
processes are essential. The operator should pay close attention to - ✔✔Surface
turbulence, Foam, Odors, & Color
✔✔In the activated sludge process, daily observation of the final clarifier is also
essential. The operator should pay close attention to - ✔✔Surface scum, Sludge
blanket, Weir Flow, Rising solids, & Clarifier overflow
✔✔In the activated sludge process, five (5) Important control parameters are -
✔✔Dissolved Oxygen level, Aerator solids level, Solids quality, Rate of returned sludge,
& Wasting rate
✔✔In the activated sludge process, Dissolved Oxygen levels throughout the aeration
basins are measured using a portable DO meter. The operator should keep DO levels
between ______ and _______. - ✔✔2 mg/L and 4.0 mg/L
✔✔In the activated sludge process, "Classic Bulking" is a common problem typically
caused by - ✔✔Low density sludge
✔✔In the activated sludge process, Sludge Rising differs from "Sludge Bulking" and
"Sludge Rising" is typically associated - ✔✔Nitrification - De-nitrification process
✔✔In the activated sludge process, techniques used to reduce "Frothing & Foaming"
typically include - ✔✔Adjusting sludge age, Reducing the amount of air, Spraying the
frothing area with water, Applying de-foaming agents
✔✔In the activated sludge process, floc is very important to the settling process. Floc is
composed primarily of - ✔✔Bacteria, Protozoa, Microscopic Animals, & Fungi
✔✔In the activated sludge plants, the operator will experience problems. Some of the
common Treatment plant problems include - ✔✔Insufficent capacity, Equipment
QUESTIONS AND ANSWERS GRADED A+
✔✔In the active sludge process, Utilization is the process where - ✔✔Food supply is
changed into a liquid state for use
✔✔In the activated sludge process, Stabilization is - ✔✔Wastes biologically converted
to water, carbon dioxide, or new cells
✔✔In the activated sludge process, the _______ is called the heart of the activated
sludge process. - ✔✔Clarifier
✔✔In the activated sludge process, factors that will influence the operation of the final
clarifier are - ✔✔Loading, solids applied, settling, thickness of solids, rate of return &
Wasting
✔✔In the activated sludge process, the clarifier will concentrate return sludge and waste
sludge about ___ to__ times the solids concentration of the mixed liquor - ✔✔two (2) to
four (4)
✔✔In the activated sludge process, for the clarifier to do its job, the ____ must be
retained long enough to allow ______ to settle and liquid to rise. - ✔✔water/ solids
✔✔In the activated sludge process, as more mixed liquor flows to the clarifier, the
thickness of the sludge blanket will - ✔✔Increase as solids accumulate
✔✔In the activated sludge process, biological solids from the bottom of the clarifier must
be returned to the aeration basin for re-seed. This process is accomplished by - ✔✔Air
lift pumps, centrifugal pumps, Diaphragm pumps, Screw pumps & Gravity Flow
✔✔In the activated sludge process, no sludge process will work properly without -
✔✔Regular removal of excess solids
✔✔In the activated sludge process, Mass Balance refers to - ✔✔Maintaining the
balance between Return Sludge Flow, Return Sludge, Aeration tank volume, Mixed
liquor suspended solids
✔✔In the activated sludge process, the terms F/M ratio is important because this refers
to - ✔✔Food to Microorganism Ratio
✔✔In the activated sludge process, the F/M Ratio is calculated by ______ the pounds
of _________ by the pounds of MLVSS in the ___________. - ✔✔Dividing/ Incoming
BOD/ aeration tank
, ✔✔In the activated sludge process, the term Gould Sludge Age refers to - ✔✔How long
in days a pound of solids stays in the aerator
✔✔In the activated sludge process, Gould Sludge Age (GSA) is calculated by -
✔✔Dividing the total pounds of TSS in the aerator by the pounds of TSS entering the
aerator as raw
✔✔In the activated sludge process, the term Mean Cell Residence Time (MCRT) refers
to - ✔✔The amount of time the living cells are kept in the plant
✔✔In the activated sludge process, daily observation of the aeration basin treatment
processes are essential. The operator should pay close attention to - ✔✔Surface
turbulence, Foam, Odors, & Color
✔✔In the activated sludge process, daily observation of the final clarifier is also
essential. The operator should pay close attention to - ✔✔Surface scum, Sludge
blanket, Weir Flow, Rising solids, & Clarifier overflow
✔✔In the activated sludge process, five (5) Important control parameters are -
✔✔Dissolved Oxygen level, Aerator solids level, Solids quality, Rate of returned sludge,
& Wasting rate
✔✔In the activated sludge process, Dissolved Oxygen levels throughout the aeration
basins are measured using a portable DO meter. The operator should keep DO levels
between ______ and _______. - ✔✔2 mg/L and 4.0 mg/L
✔✔In the activated sludge process, "Classic Bulking" is a common problem typically
caused by - ✔✔Low density sludge
✔✔In the activated sludge process, Sludge Rising differs from "Sludge Bulking" and
"Sludge Rising" is typically associated - ✔✔Nitrification - De-nitrification process
✔✔In the activated sludge process, techniques used to reduce "Frothing & Foaming"
typically include - ✔✔Adjusting sludge age, Reducing the amount of air, Spraying the
frothing area with water, Applying de-foaming agents
✔✔In the activated sludge process, floc is very important to the settling process. Floc is
composed primarily of - ✔✔Bacteria, Protozoa, Microscopic Animals, & Fungi
✔✔In the activated sludge plants, the operator will experience problems. Some of the
common Treatment plant problems include - ✔✔Insufficent capacity, Equipment
