CA Wastewater Grade 3/ 63 Sample
Questions/ 2024-2025.
An activated sludge plant with an MCRT of over 10-days is normally
considered an extended aeration plant. - Answer: T
Wasting of activated sludge on a continuous basis is the preferred
method. - Answer: T
SVI is used as an indicator for clarifier stability. - Answer: T
The standard BOD test measures the amount of dissolved oxygen
consumed by bacteria as they utilize waste for food during a 8 day period
at 15 degrees Celsius. - Answer: F
When operating an aerobic digester be sure to keep the feed sludge
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,volatile solid concentration high or else the percent reduction will decrease - Answer: F
Any sample can be "fixed" for later testing. - Answer: F
The nice thing about anaerobic process is the operator can smoke
since no oxygen is present for a fire to start. - Answer: F
Dissolved oxygen in an aeration tank should be at a minimum of 1 ppm
for biological nitrification - Answer: T
Fluffy white foam indicates low aerator solids concentration, while leathery brown foam
indicates high solids concentration. - Answer: T
When an anaerobic digester is becoming upset, the first sign will be increased alkalinity and
decreased volatile acid concentration - Answer: F
Surface aerator oxygen transfer efficiency increases as submergence decreases and the oxygen
transfer efficiency increases - Answer: F
When chlorine is used before disinfection for odor control it is not necessary to satisfy a
chlorine demand. - Answer: F
Biological secondary treatment processes should remove at least 85% of the influent BOD -
Answer: T
Short detention times are normal for package plants - Answer: F
Nitrification is the process where by ammonia is converted to nitrogen
gas. - Answer: F
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, In order for nitrification to occur you must have an anaerobic process - Answer: F
Chlorine is lighter than air and will collect on the ceiling if a leak occurs. - Answer: F
A complete-mix activated sludge basin is normally square allowing
complete MLSS mixing. - Answer: T
Blanks are used in the BOD test to calculate dilution water DO uptake - Answer: T
Flexible piping sometimes called a pigtail should connect a chlorine
container to stationary piping. - Answer: T
Carbon dioxide will lower the pH of water. - Answer: T
When chlorine gas combines with moisture in the air it forms
hydrochloric gas. - Answer: T
A high hydrogen sulfide gas concentration is required before your
sense of smell will be dulled. - Answer: F
Alkalinity is the key control for an activated sludge basin. - Answer: F
30 days is normally required for anaerobic digestion - Answer: T
The first sign that an anaerobic digester is becoming sick is normally
A. a pH change.
B. a decrease in gas production.
C. a change in the volatile acid/alkalinity relationship.
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Questions/ 2024-2025.
An activated sludge plant with an MCRT of over 10-days is normally
considered an extended aeration plant. - Answer: T
Wasting of activated sludge on a continuous basis is the preferred
method. - Answer: T
SVI is used as an indicator for clarifier stability. - Answer: T
The standard BOD test measures the amount of dissolved oxygen
consumed by bacteria as they utilize waste for food during a 8 day period
at 15 degrees Celsius. - Answer: F
When operating an aerobic digester be sure to keep the feed sludge
Page 1 of 17
,volatile solid concentration high or else the percent reduction will decrease - Answer: F
Any sample can be "fixed" for later testing. - Answer: F
The nice thing about anaerobic process is the operator can smoke
since no oxygen is present for a fire to start. - Answer: F
Dissolved oxygen in an aeration tank should be at a minimum of 1 ppm
for biological nitrification - Answer: T
Fluffy white foam indicates low aerator solids concentration, while leathery brown foam
indicates high solids concentration. - Answer: T
When an anaerobic digester is becoming upset, the first sign will be increased alkalinity and
decreased volatile acid concentration - Answer: F
Surface aerator oxygen transfer efficiency increases as submergence decreases and the oxygen
transfer efficiency increases - Answer: F
When chlorine is used before disinfection for odor control it is not necessary to satisfy a
chlorine demand. - Answer: F
Biological secondary treatment processes should remove at least 85% of the influent BOD -
Answer: T
Short detention times are normal for package plants - Answer: F
Nitrification is the process where by ammonia is converted to nitrogen
gas. - Answer: F
Page 2 of 17
, In order for nitrification to occur you must have an anaerobic process - Answer: F
Chlorine is lighter than air and will collect on the ceiling if a leak occurs. - Answer: F
A complete-mix activated sludge basin is normally square allowing
complete MLSS mixing. - Answer: T
Blanks are used in the BOD test to calculate dilution water DO uptake - Answer: T
Flexible piping sometimes called a pigtail should connect a chlorine
container to stationary piping. - Answer: T
Carbon dioxide will lower the pH of water. - Answer: T
When chlorine gas combines with moisture in the air it forms
hydrochloric gas. - Answer: T
A high hydrogen sulfide gas concentration is required before your
sense of smell will be dulled. - Answer: F
Alkalinity is the key control for an activated sludge basin. - Answer: F
30 days is normally required for anaerobic digestion - Answer: T
The first sign that an anaerobic digester is becoming sick is normally
A. a pH change.
B. a decrease in gas production.
C. a change in the volatile acid/alkalinity relationship.
Page 3 of 17
