ABC Wastewater Treatment Grade 3 Exam –
Questions With Relevant Solutions
BOD incubation period and temperature Correct Answer - 5
days at 20 C
Time to hold BOD sample in fridge Correct Answer - 48 hours
4C
What preservative do you add to store COD samples? Correct
Answer - Sulfuric Acid H2SO4
Ammonia incubation period and temperature Correct Answer -
28 days at 4 C
What preservative do you add to store Ammonia Correct Answer
- Sulfuric Acid H2SO4
Fecal Coliform holding time is Correct Answer - 8 hours
A drip trap for an anaerobic digester does what Correct Answer -
Removes condensate in the gas piping system
Chemical used to raise pH in a digester Correct Answer -
Sodium bicarbonate or Lime
What causes the pH in an anaerobic digester to decrease Correct
Answer - Increase in volatile/alkalinity ratio
Heterotrophs feed on Correct Answer - Organic carbon
Autotrophs feed on Correct Answer - Inorganic carbon. They
produce their own nutrients.
, Ensure accurate lab results through Correct Answer - duplicity
Which is larger, BOD or COD? Correct Answer - COD is larger
Phosphorous removal ratio of 300:5:1 Correct Answer - COD :
Nitrogen : Phosphorous
Phosphorous removal ratio of 100:5:1 Correct Answer - BOD :
Nitrogen : Phosphorous
Pump efficiency with 86% pump power and 86% motor
functionality Correct Answer - 73.96%
First stage of an upset digester? Correct Answer - Volatile
acids increase, alkalinity decrease
Digester temperature can be raised by how much per day? Correct
Answer - 1F
Average temperature of an anaerobic digester? Correct Answer -
95 F
Belt Press Thickener solids are thin so you Correct Answer -
decrease the belt retention time
Centrifugal pump temperature is hot so operator cuts flow to 50%,
temperature will Correct Answer - Cool down
Advantage of egg shaped digester over cylindrical Correct Answer
- less scum accumulation
Ohms versus Kilowatts Correct Answer - Ohms = resistance,
Kilowatts = Power
Questions With Relevant Solutions
BOD incubation period and temperature Correct Answer - 5
days at 20 C
Time to hold BOD sample in fridge Correct Answer - 48 hours
4C
What preservative do you add to store COD samples? Correct
Answer - Sulfuric Acid H2SO4
Ammonia incubation period and temperature Correct Answer -
28 days at 4 C
What preservative do you add to store Ammonia Correct Answer
- Sulfuric Acid H2SO4
Fecal Coliform holding time is Correct Answer - 8 hours
A drip trap for an anaerobic digester does what Correct Answer -
Removes condensate in the gas piping system
Chemical used to raise pH in a digester Correct Answer -
Sodium bicarbonate or Lime
What causes the pH in an anaerobic digester to decrease Correct
Answer - Increase in volatile/alkalinity ratio
Heterotrophs feed on Correct Answer - Organic carbon
Autotrophs feed on Correct Answer - Inorganic carbon. They
produce their own nutrients.
, Ensure accurate lab results through Correct Answer - duplicity
Which is larger, BOD or COD? Correct Answer - COD is larger
Phosphorous removal ratio of 300:5:1 Correct Answer - COD :
Nitrogen : Phosphorous
Phosphorous removal ratio of 100:5:1 Correct Answer - BOD :
Nitrogen : Phosphorous
Pump efficiency with 86% pump power and 86% motor
functionality Correct Answer - 73.96%
First stage of an upset digester? Correct Answer - Volatile
acids increase, alkalinity decrease
Digester temperature can be raised by how much per day? Correct
Answer - 1F
Average temperature of an anaerobic digester? Correct Answer -
95 F
Belt Press Thickener solids are thin so you Correct Answer -
decrease the belt retention time
Centrifugal pump temperature is hot so operator cuts flow to 50%,
temperature will Correct Answer - Cool down
Advantage of egg shaped digester over cylindrical Correct Answer
- less scum accumulation
Ohms versus Kilowatts Correct Answer - Ohms = resistance,
Kilowatts = Power
