Operation of Wastewater Treatment Plants (Levels 1-2 || || || || || || ||
Exam Prep) question s with verified answers
|| || || || || ||
An Imhoff cone is used to measure _______ solids.
|| || || || || || || ||
A. suspended
||
B. colloidal
|| ||
C. volatile
||
D. settleable - correct answer✔✔D. settleable
|| || || || || ||
(Operation of Wastewater Treatment Plants, Volume 1
|| || || || || ||
by Kenneth D. Kerri)
|| || ||
A _____ flume is widely used for measuring wastewater flow. - correct answer✔✔Parshall
|| || || || || || || || || || || ||
(Operation of Wastewater Treatment Plants, Volume 1
|| || || || || ||
by Kenneth D. Kerri)
|| || ||
Velocity of flow in a grit channel must be reduced to a range of ____ to _____ fps in order
|| || || || || || || || || || || || || || || || || || || ||
for grit to properly settle. - correct answer✔✔.7 to 1.4 fps
|| || || || || || || || || ||
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
|| || || || || || ||
by Kenneth D. Kerri)
|| || ||
,With respect to grit removal systems, grit is traditionally defined as particles larger than
|| || || || || || || || || || || || || ||
0.21mm (0.008 in) (65 mesh) and with a specific gravity of greater than ______. - correct
|| || || || || || || || || || || || || || || ||
answer✔✔specific gravity of grit is 2.65 or greater || || || || || || || ||
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
|| || || || || || || ||
Mechanically cleaned bar screens feature bars set at _____ to _____ degrees from vertical. -
|| || || || || || || || || || || || || || ||
correct answer✔✔Bars set at 0 to 30 degrees from vertical.
|| || || || || || || || ||
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
|| || || || || || || ||
Manually cleaned bar screens feature bars set at _____ to _____ degrees from vertical to
|| || || || || || || || || || || || || || ||
facilitate cleaning. - correct answer✔✔Bars set at 30 to 45 degrees from vertical to facilitate
|| || || || || || || || || || || || || || ||
cleaning. Primarily used in older or smaller treatment facilities, or in bypass channels.
|| || || || || || || || || || || ||
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
|| || || || || || || ||
The BOD test measures the amount of oxygen that is consumed while a sample of
|| || || || || || || || || || || || || || ||
wastewater is incubated in the dark at a temperature of _____ °C for _____ days (± _____
|| || || || || || || || || || || || || || || || ||
hours) - correct answer✔✔The BOD test measures the amount of oxygen that is consumed
|| || || || || || || || || || || || || ||
while a sample of wastewater is incubated in the dark at a temperature of 20 °C for 5 days
|| || || || || || || || || || || || || || || || || || ||
(± 3 hours)
|| ||
(USGS Book 9-A7 (Third Edition) Five-Day Biochemical Oxygen Demand)
|| || || || || || || ||
What do we mean by Total Dissolved Solids (TDS) in wastewater? - correct answer✔✔All
|| || || || || || || || || || || || || ||
the solids that cannot be filtered out of the water
|| || || || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
,What do we mean by Total Suspended Solids (TSS) in wastewater? - correct answer✔✔All
|| || || || || || || || || || || || || ||
the solids that can be filtered out including: settleable solids and non-settleable solids
|| || || || || || || || || || || || ||
(colloids)
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
The wastewater in a sewer line should move at a speed that will prevent the deposition and
|| || || || || || || || || || || || || || || || ||
buildup of solids in the sewer; this is called a "scouring velocity". A minimum velocity of
|| || || || || || || || || || || || || || || ||
_____ fps provides this scouring or self-cleaning velocity. - correct answer✔✔The
|| || || || || || || || || || ||
wastewater in a sewer line should move at a speed that will prevent the deposition and
|| || || || || || || || || || || || || || || ||
buildup of solids in the sewer; this is called a "scouring velocity". A minimum velocity of 2
|| || || || || || || || || || || || || || || || ||
fps provides this scouring or self-cleaning velocity.
|| || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Wastewater treatment ponds: Facultative ponds are _____ feet deep - correct
|| || || || || || || || || || ||
answer✔✔Facultative ponds are 4-8 feet deep || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Wastewater treatment ponds: Anaerobic ponds are _____ feet deep - correct
|| || || || || || || || || || ||
answer✔✔Anaerobic ponds are >14 feet in depth || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
, Typical Primary Clarifier Efficiencies: Settleable Solids expected removal efficiency _____%
|| || || || || || || || || ||
to _____% - correct answer✔✔Typical Primary Clarifier Efficiencies: Settleable Solids
|| || || || || || || || || ||
expected removal efficiency 95% to 99% || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal efficiency _____%
|| || || || || || || || ||
to _____% - correct answer✔✔Typical Primary Clarifier Efficiencies: Suspended Solids
|| || || || || || || || || || ||
expected removal efficiency 40% to 60% || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Typical Primary Clarifier Efficiencies: Total Solids expected removal efficiency _____% to
|| || || || || || || || || || ||
_____% - correct answer✔✔Typical Primary Clarifier Efficiencies: Total Solids expected
|| || || || || || || || || ||
removal efficiency 10% to 15% || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected
|| || || || || || || || ||
removal efficiency _____% to _____% - correct answer✔✔Typical Primary Clarifier
|| || || || || || || || || ||
Efficiencies: Biochemical Oxygen Demand (BOD) expected removal efficiency 20% to 50%
|| || || || || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Sludge septicity in the primary clarifier can be recognized when:
|| || || || || || || || || ||
A. sludge gasification causes large clumps of sludge to float on the water surface.
|| || || || || || || || || || || || || ||
Exam Prep) question s with verified answers
|| || || || || ||
An Imhoff cone is used to measure _______ solids.
|| || || || || || || ||
A. suspended
||
B. colloidal
|| ||
C. volatile
||
D. settleable - correct answer✔✔D. settleable
|| || || || || ||
(Operation of Wastewater Treatment Plants, Volume 1
|| || || || || ||
by Kenneth D. Kerri)
|| || ||
A _____ flume is widely used for measuring wastewater flow. - correct answer✔✔Parshall
|| || || || || || || || || || || ||
(Operation of Wastewater Treatment Plants, Volume 1
|| || || || || ||
by Kenneth D. Kerri)
|| || ||
Velocity of flow in a grit channel must be reduced to a range of ____ to _____ fps in order
|| || || || || || || || || || || || || || || || || || || ||
for grit to properly settle. - correct answer✔✔.7 to 1.4 fps
|| || || || || || || || || ||
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
|| || || || || || ||
by Kenneth D. Kerri)
|| || ||
,With respect to grit removal systems, grit is traditionally defined as particles larger than
|| || || || || || || || || || || || || ||
0.21mm (0.008 in) (65 mesh) and with a specific gravity of greater than ______. - correct
|| || || || || || || || || || || || || || || ||
answer✔✔specific gravity of grit is 2.65 or greater || || || || || || || ||
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
|| || || || || || || ||
Mechanically cleaned bar screens feature bars set at _____ to _____ degrees from vertical. -
|| || || || || || || || || || || || || || ||
correct answer✔✔Bars set at 0 to 30 degrees from vertical.
|| || || || || || || || ||
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
|| || || || || || || ||
Manually cleaned bar screens feature bars set at _____ to _____ degrees from vertical to
|| || || || || || || || || || || || || || ||
facilitate cleaning. - correct answer✔✔Bars set at 30 to 45 degrees from vertical to facilitate
|| || || || || || || || || || || || || || ||
cleaning. Primarily used in older or smaller treatment facilities, or in bypass channels.
|| || || || || || || || || || || ||
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
|| || || || || || || ||
The BOD test measures the amount of oxygen that is consumed while a sample of
|| || || || || || || || || || || || || || ||
wastewater is incubated in the dark at a temperature of _____ °C for _____ days (± _____
|| || || || || || || || || || || || || || || || ||
hours) - correct answer✔✔The BOD test measures the amount of oxygen that is consumed
|| || || || || || || || || || || || || ||
while a sample of wastewater is incubated in the dark at a temperature of 20 °C for 5 days
|| || || || || || || || || || || || || || || || || || ||
(± 3 hours)
|| ||
(USGS Book 9-A7 (Third Edition) Five-Day Biochemical Oxygen Demand)
|| || || || || || || ||
What do we mean by Total Dissolved Solids (TDS) in wastewater? - correct answer✔✔All
|| || || || || || || || || || || || || ||
the solids that cannot be filtered out of the water
|| || || || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
,What do we mean by Total Suspended Solids (TSS) in wastewater? - correct answer✔✔All
|| || || || || || || || || || || || || ||
the solids that can be filtered out including: settleable solids and non-settleable solids
|| || || || || || || || || || || || ||
(colloids)
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
The wastewater in a sewer line should move at a speed that will prevent the deposition and
|| || || || || || || || || || || || || || || || ||
buildup of solids in the sewer; this is called a "scouring velocity". A minimum velocity of
|| || || || || || || || || || || || || || || ||
_____ fps provides this scouring or self-cleaning velocity. - correct answer✔✔The
|| || || || || || || || || || ||
wastewater in a sewer line should move at a speed that will prevent the deposition and
|| || || || || || || || || || || || || || || ||
buildup of solids in the sewer; this is called a "scouring velocity". A minimum velocity of 2
|| || || || || || || || || || || || || || || || ||
fps provides this scouring or self-cleaning velocity.
|| || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Wastewater treatment ponds: Facultative ponds are _____ feet deep - correct
|| || || || || || || || || || ||
answer✔✔Facultative ponds are 4-8 feet deep || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Wastewater treatment ponds: Anaerobic ponds are _____ feet deep - correct
|| || || || || || || || || || ||
answer✔✔Anaerobic ponds are >14 feet in depth || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
, Typical Primary Clarifier Efficiencies: Settleable Solids expected removal efficiency _____%
|| || || || || || || || || ||
to _____% - correct answer✔✔Typical Primary Clarifier Efficiencies: Settleable Solids
|| || || || || || || || || ||
expected removal efficiency 95% to 99% || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal efficiency _____%
|| || || || || || || || ||
to _____% - correct answer✔✔Typical Primary Clarifier Efficiencies: Suspended Solids
|| || || || || || || || || || ||
expected removal efficiency 40% to 60% || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Typical Primary Clarifier Efficiencies: Total Solids expected removal efficiency _____% to
|| || || || || || || || || || ||
_____% - correct answer✔✔Typical Primary Clarifier Efficiencies: Total Solids expected
|| || || || || || || || || ||
removal efficiency 10% to 15% || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected
|| || || || || || || || ||
removal efficiency _____% to _____% - correct answer✔✔Typical Primary Clarifier
|| || || || || || || || || ||
Efficiencies: Biochemical Oxygen Demand (BOD) expected removal efficiency 20% to 50%
|| || || || || || || || || ||
(New Mexico Wastewater Systems Operator Certification Study Manual)
|| || || || || || ||
Sludge septicity in the primary clarifier can be recognized when:
|| || || || || || || || || ||
A. sludge gasification causes large clumps of sludge to float on the water surface.
|| || || || || || || || || || || || || ||
