OPERATION OF WASTEWATER
TREATMENT PLANTS (LEVELS 1-2
EXAM PREP) QUESTIONS AND
ANSWERS
An Imhoff cone is used to measure________solids.
sw sw sw sw sw sw
A. suspended
sw
B. colloidal
sw
C. volatile
sw
D. settleable - ans-D. settleable
sw sw sw sw
(Operation of Wastewater Treatment Plants, Volume 1
sw sw sw sw sw sw
by Kenneth D. Kerri)
sw sw sw
A _____ flume is widely used for measuring wastewater flow. - ans-Parshall
sw sw sw sw sw sw sw sw sw sw sw
(Operation of Wastewater Treatment Plants, Volume 1
sw sw sw sw sw sw
by Kenneth D. Kerri)
sw sw sw
Velocity of flow in a grit channel must be reduced to a range of ____ to _____ fps in or
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
der for grit to properly settle. - ans-.7 to 1.4 fps
sw sw sw sw sw sw sw sw sw sw
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
sw sw sw sw sw sw sw
by Kenneth D. Kerri)
sw sw sw
With respect to grit removal systems, grit is traditionally defined as particles larger than
sw sw sw sw sw sw sw sw sw sw sw sw sw s
0.21mm (0.008 in) (65 mesh) and with a specific gravity of greater than ______. - ans-
w sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
specific gravity of grit is 2.65 or greater
sw sw sw sw sw sw sw
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
sw sw sw sw sw sw sw sw
Mechanically cleaned bar screens feature bars set at _____ to _____ degrees from ver
sw sw sw sw sw sw sw sw sw sw sw sw sw
tical. - ans-Bars set at 0 to 30 degrees from vertical.
sw sw sw sw sw sw sw sw sw sw
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
sw sw sw sw sw sw sw sw
,Manually cleaned bar screens feature bars set at _____ to _____ degrees from vertical
sw sw sw sw sw sw sw sw sw sw sw sw sw s
to facilitate cleaning. - ans-
w sw sw sw sw
Bars set at 30 to 45 degrees from vertical to facilitate cleaning. Primarily used in older
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
or smaller treatment facilities, or in bypass channels.
sw sw sw sw sw sw sw
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
sw sw sw sw sw sw sw sw
The BOD test measures the amount of oxygen that is consumed while a sample of was
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
tewater is incubated in the dark at a temperature of _____ °C for _____ days (± _____
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
hours) - ans- sw sw
The BOD test measures the amount of oxygen that is consumed while a sample of was
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
tewater is incubated in the dark at a temperature of 20 °C for 5 days (± 3 hours)
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
(USGS Book 9-A7 (Third Edition) Five-Day Biochemical Oxygen Demand)
sw sw sw sw sw sw sw sw
What do we mean by Total Dissolved Solids (TDS) in wastewater? - ans-
sw sw sw sw sw sw sw sw sw sw sw sw
All the solids that cannot be filtered out of the water
sw sw sw sw sw sw sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
What do we mean by Total Suspended Solids (TSS) in wastewater? - ans-
sw sw sw sw sw sw sw sw sw sw sw sw
All the solids that can be filtered out including: settleable solids and non-
sw sw sw sw sw sw sw sw sw sw sw sw
settleable solids (colloids) sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
The wastewater in a sewer line should move at a speed that will prevent the deposition
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw s
wand buildup of solids in the sewer; this is called a "scouring velocity". A minimum veloci
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
ty of _____ fps provides this scouring or self-cleaning velocity. - ans-
sw sw sw sw sw sw sw sw sw sw sw
The wastewater in a sewer line should move at a speed that will prevent the deposition
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw s
wand buildup of solids in the sewer; this is called a "scouring velocity". A minimum veloci
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
ty of 2 fps provides this scouring or self-cleaning velocity.
sw sw sw sw sw sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Wastewater treatment ponds: Facultative ponds are _____ feet deep - ans-
sw sw sw sw sw sw sw sw sw sw
Facultative ponds are 4-8 feet deep sw sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Wastewater treatment ponds: Anaerobic ponds are _____ feet deep - ans-
sw sw sw sw sw sw sw sw sw sw
Anaerobic ponds are >14 feet in depth sw sw sw sw sw sw
, (New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Settleable Solids expected removal efficiency ___
sw sw sw sw sw sw sw sw sw
__% to _____% - ans-
sw sw sw sw
Typical Primary Clarifier Efficiencies: Settleable Solids expected removal efficiency 95
sw sw sw sw sw sw sw sw sw
% to 99%
sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal efficiency __
sw sw sw sw sw sw sw sw sw
___% to _____% - ans-
sw sw sw sw
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal efficiency 40
sw sw sw sw sw sw sw sw sw
% to 60%
sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Total Solids expected removal efficiency _____
sw sw sw sw sw sw sw sw sw
% to _____% - ans-
sw sw sw sw
Typical Primary Clarifier Efficiencies: Total Solids expected removal efficiency 10% to 1
sw sw sw sw sw sw sw sw sw sw sw
5%
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected re
sw sw sw sw sw sw sw sw sw
moval efficiency _____% to _____% - ans-
sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected re
sw sw sw sw sw sw sw sw sw
moval efficiency 20% to 50%
sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Sludge septicity in the primary clarifier can be recognized when:
sw sw sw sw sw sw sw sw sw
A. sludge gasification causes large clumps of sludge to float on the water surface.
sw sw sw sw sw sw sw sw sw sw sw sw sw
B. Primary clarifier foam is black
sw sw sw sw sw
C. The Specific Oxygen Uptake Rate (SOUR) in the primary clarifier is greater than 30
sw sw sw sw sw sw sw sw sw sw sw sw sw sw
00 mg O2/L/hr
sw sw
D. The sludge contains from 4.0 to 8.0 percent dry solids in TS laboratory testing
sw sw sw sw sw sw sw sw sw sw sw sw sw sw
E. All of the above - ans-
sw sw sw sw sw sw
A. sludge gasification causes large clumps of sludge to float on the water surface.
sw sw sw sw sw sw sw sw sw sw sw sw sw
Pump cavitation may be caused by:
sw sw sw sw sw
TREATMENT PLANTS (LEVELS 1-2
EXAM PREP) QUESTIONS AND
ANSWERS
An Imhoff cone is used to measure________solids.
sw sw sw sw sw sw
A. suspended
sw
B. colloidal
sw
C. volatile
sw
D. settleable - ans-D. settleable
sw sw sw sw
(Operation of Wastewater Treatment Plants, Volume 1
sw sw sw sw sw sw
by Kenneth D. Kerri)
sw sw sw
A _____ flume is widely used for measuring wastewater flow. - ans-Parshall
sw sw sw sw sw sw sw sw sw sw sw
(Operation of Wastewater Treatment Plants, Volume 1
sw sw sw sw sw sw
by Kenneth D. Kerri)
sw sw sw
Velocity of flow in a grit channel must be reduced to a range of ____ to _____ fps in or
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
der for grit to properly settle. - ans-.7 to 1.4 fps
sw sw sw sw sw sw sw sw sw sw
(Operation of Wastewater Treatment Plants, Volume 1, 3.33
sw sw sw sw sw sw sw
by Kenneth D. Kerri)
sw sw sw
With respect to grit removal systems, grit is traditionally defined as particles larger than
sw sw sw sw sw sw sw sw sw sw sw sw sw s
0.21mm (0.008 in) (65 mesh) and with a specific gravity of greater than ______. - ans-
w sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
specific gravity of grit is 2.65 or greater
sw sw sw sw sw sw sw
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
sw sw sw sw sw sw sw sw
Mechanically cleaned bar screens feature bars set at _____ to _____ degrees from ver
sw sw sw sw sw sw sw sw sw sw sw sw sw
tical. - ans-Bars set at 0 to 30 degrees from vertical.
sw sw sw sw sw sw sw sw sw sw
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
sw sw sw sw sw sw sw sw
,Manually cleaned bar screens feature bars set at _____ to _____ degrees from vertical
sw sw sw sw sw sw sw sw sw sw sw sw sw s
to facilitate cleaning. - ans-
w sw sw sw sw
Bars set at 30 to 45 degrees from vertical to facilitate cleaning. Primarily used in older
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
or smaller treatment facilities, or in bypass channels.
sw sw sw sw sw sw sw
(EPA Wastewater Technology Fact Sheet, Screening and Grit Removal)
sw sw sw sw sw sw sw sw
The BOD test measures the amount of oxygen that is consumed while a sample of was
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
tewater is incubated in the dark at a temperature of _____ °C for _____ days (± _____
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
hours) - ans- sw sw
The BOD test measures the amount of oxygen that is consumed while a sample of was
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
tewater is incubated in the dark at a temperature of 20 °C for 5 days (± 3 hours)
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
(USGS Book 9-A7 (Third Edition) Five-Day Biochemical Oxygen Demand)
sw sw sw sw sw sw sw sw
What do we mean by Total Dissolved Solids (TDS) in wastewater? - ans-
sw sw sw sw sw sw sw sw sw sw sw sw
All the solids that cannot be filtered out of the water
sw sw sw sw sw sw sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
What do we mean by Total Suspended Solids (TSS) in wastewater? - ans-
sw sw sw sw sw sw sw sw sw sw sw sw
All the solids that can be filtered out including: settleable solids and non-
sw sw sw sw sw sw sw sw sw sw sw sw
settleable solids (colloids) sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
The wastewater in a sewer line should move at a speed that will prevent the deposition
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw s
wand buildup of solids in the sewer; this is called a "scouring velocity". A minimum veloci
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
ty of _____ fps provides this scouring or self-cleaning velocity. - ans-
sw sw sw sw sw sw sw sw sw sw sw
The wastewater in a sewer line should move at a speed that will prevent the deposition
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw s
wand buildup of solids in the sewer; this is called a "scouring velocity". A minimum veloci
sw sw sw sw sw sw sw sw sw sw sw sw sw sw sw
ty of 2 fps provides this scouring or self-cleaning velocity.
sw sw sw sw sw sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Wastewater treatment ponds: Facultative ponds are _____ feet deep - ans-
sw sw sw sw sw sw sw sw sw sw
Facultative ponds are 4-8 feet deep sw sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Wastewater treatment ponds: Anaerobic ponds are _____ feet deep - ans-
sw sw sw sw sw sw sw sw sw sw
Anaerobic ponds are >14 feet in depth sw sw sw sw sw sw
, (New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Settleable Solids expected removal efficiency ___
sw sw sw sw sw sw sw sw sw
__% to _____% - ans-
sw sw sw sw
Typical Primary Clarifier Efficiencies: Settleable Solids expected removal efficiency 95
sw sw sw sw sw sw sw sw sw
% to 99%
sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal efficiency __
sw sw sw sw sw sw sw sw sw
___% to _____% - ans-
sw sw sw sw
Typical Primary Clarifier Efficiencies: Suspended Solids expected removal efficiency 40
sw sw sw sw sw sw sw sw sw
% to 60%
sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Total Solids expected removal efficiency _____
sw sw sw sw sw sw sw sw sw
% to _____% - ans-
sw sw sw sw
Typical Primary Clarifier Efficiencies: Total Solids expected removal efficiency 10% to 1
sw sw sw sw sw sw sw sw sw sw sw
5%
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected re
sw sw sw sw sw sw sw sw sw
moval efficiency _____% to _____% - ans-
sw sw sw sw sw sw
Typical Primary Clarifier Efficiencies: Biochemical Oxygen Demand (BOD) expected re
sw sw sw sw sw sw sw sw sw
moval efficiency 20% to 50%
sw sw sw sw
(New Mexico Wastewater Systems Operator Certification Study Manual)
sw sw sw sw sw sw sw
Sludge septicity in the primary clarifier can be recognized when:
sw sw sw sw sw sw sw sw sw
A. sludge gasification causes large clumps of sludge to float on the water surface.
sw sw sw sw sw sw sw sw sw sw sw sw sw
B. Primary clarifier foam is black
sw sw sw sw sw
C. The Specific Oxygen Uptake Rate (SOUR) in the primary clarifier is greater than 30
sw sw sw sw sw sw sw sw sw sw sw sw sw sw
00 mg O2/L/hr
sw sw
D. The sludge contains from 4.0 to 8.0 percent dry solids in TS laboratory testing
sw sw sw sw sw sw sw sw sw sw sw sw sw sw
E. All of the above - ans-
sw sw sw sw sw sw
A. sludge gasification causes large clumps of sludge to float on the water surface.
sw sw sw sw sw sw sw sw sw sw sw sw sw
Pump cavitation may be caused by:
sw sw sw sw sw
