WASTEWATER PRACTICE TEST
V
COMPLETE DETAILED CASE STUDY
A spray field has a total of 80 acres and is divided into four equal zones. Only one zone may be Operated
at a time and the permit states that no more than 4 inches of water can be applied to the zone. How
long can a zone be operated at a rate of 0.7 MGD before it must be rotated to another zone? - 3.1 Days
4/12= 0.33
43560 x 0.33= 14.374.8
14.374.8 x 7.48= 107,523.5
107,523.5 x 20= 2,150,460
2,150,460/700,000= 3.1 Days
Most activated sludge mixed liquor suspended solids fall into a range of what percent volatile content for
municipal waste when the process is operating properlv? - 70 to 80%
What may be the first corrective action taken to resolve floating sludge conditions in a secondary
clarifier, given these observations: -SVI is 132; microscopic exam reveals abundance of filamentous
organisms. - Increase the DO
What is another term for organic solids? - Volatile
Which repair kit is designed for use with 150-pound chlorine cylinders? - A kit
If a gallon of water weighs 8.34 lbs and a cubic foot of water holds 7.48 gallons, how much does a cubic
foot of water weight? - 62.4
What is the best adiustment to make (from the list of possible answers) if solids are rising in the
secondary clarifier accompanied by small as bubbles and solids that break apart when they surface? -
Decrease aeration DO
, Is a high-rate aeration process typically overloaded or underloaded by design? - Overloaded
What does the term aliquot mean? - portion of a sample
What is another term for inorganic solids? - non-volatile
What is the common preservation method for a wastewater sample to be tested for CBOD5? - Cool to 4°
Celsius
in which form are nutrients better utilized by microorganisms in a biological treatment process? - Soluble
Which of the following best describe the term anoxic? - Nearly anaerobic; very low dissolved oxygen but
nitrates and/or nitrites are present
What is the typical RAS-to-Q ratio for an extended aeration activated sludge process? - 75 to 100%
Which adjustment will create an increase contact time in the aeration tank? - Decrease the RAS rate
What adjustment will help if solids are rising in the secondary clarifier accompanied by large septic gas
bubbles? - Increase RAS rate
What happens to the activity rate of activated sludge microorganisms as the wastewater temperature
increases by 10 ° C? - It doubles
Which term is most related to vector attraction reduction in an aerobic digester? - SOUR
What are the 'two reaction-forming stages of anaerobic digestion? - Acid and Methane
V
COMPLETE DETAILED CASE STUDY
A spray field has a total of 80 acres and is divided into four equal zones. Only one zone may be Operated
at a time and the permit states that no more than 4 inches of water can be applied to the zone. How
long can a zone be operated at a rate of 0.7 MGD before it must be rotated to another zone? - 3.1 Days
4/12= 0.33
43560 x 0.33= 14.374.8
14.374.8 x 7.48= 107,523.5
107,523.5 x 20= 2,150,460
2,150,460/700,000= 3.1 Days
Most activated sludge mixed liquor suspended solids fall into a range of what percent volatile content for
municipal waste when the process is operating properlv? - 70 to 80%
What may be the first corrective action taken to resolve floating sludge conditions in a secondary
clarifier, given these observations: -SVI is 132; microscopic exam reveals abundance of filamentous
organisms. - Increase the DO
What is another term for organic solids? - Volatile
Which repair kit is designed for use with 150-pound chlorine cylinders? - A kit
If a gallon of water weighs 8.34 lbs and a cubic foot of water holds 7.48 gallons, how much does a cubic
foot of water weight? - 62.4
What is the best adiustment to make (from the list of possible answers) if solids are rising in the
secondary clarifier accompanied by small as bubbles and solids that break apart when they surface? -
Decrease aeration DO
, Is a high-rate aeration process typically overloaded or underloaded by design? - Overloaded
What does the term aliquot mean? - portion of a sample
What is another term for inorganic solids? - non-volatile
What is the common preservation method for a wastewater sample to be tested for CBOD5? - Cool to 4°
Celsius
in which form are nutrients better utilized by microorganisms in a biological treatment process? - Soluble
Which of the following best describe the term anoxic? - Nearly anaerobic; very low dissolved oxygen but
nitrates and/or nitrites are present
What is the typical RAS-to-Q ratio for an extended aeration activated sludge process? - 75 to 100%
Which adjustment will create an increase contact time in the aeration tank? - Decrease the RAS rate
What adjustment will help if solids are rising in the secondary clarifier accompanied by large septic gas
bubbles? - Increase RAS rate
What happens to the activity rate of activated sludge microorganisms as the wastewater temperature
increases by 10 ° C? - It doubles
Which term is most related to vector attraction reduction in an aerobic digester? - SOUR
What are the 'two reaction-forming stages of anaerobic digestion? - Acid and Methane
