Wastewater Grade 2 Study Questions with correct answers

Wastewater Grade 2 Study |\ |\ |\ |\




Questions with correct answers |\ |\ |\




What is the methane content in a properly operating
|\ |\ |\ |\ |\ |\ |\ |\ |\



anaerobic digester? |\




a. 30 to 35% by volume
|\ |\ |\ |\ |\




b. 1 to 2% by volume
|\ |\ |\ |\ |\




c. 65 to 70% by volume
|\ |\ |\ |\ |\




d. 15 to 20 % by volume - CORRECT ANSWERS ✔✔c
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\




What will the addition of chlorine gas do to the pH of
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



wastewater?


a. Moderately increase the pH
|\ |\ |\ |\




b. pH will not be affected
|\ |\ |\ |\ |\




c. Significantly increase the pH
|\ |\ |\ |\




d. Decrease the pH - CORRECT ANSWERS ✔✔d
|\ |\ |\ |\ |\ |\ |\




What is the purpose of a Parshall flume?
|\ |\ |\ |\ |\ |\ |\




a. Measure turbidity
|\ |\

,b. Measure flowrate
|\ |\




c. Measure settling rate
|\ |\ |\




d. Measure solids content - CORRECT ANSWERS ✔✔b
|\ |\ |\ |\ |\ |\ |\




What is the typical removal efficiency of settleable solids
|\ |\ |\ |\ |\ |\ |\ |\ |\



in a primary clarifier?
|\ |\ |\




a. 95 to 99%
|\ |\ |\




b. 40 to 60%
|\ |\ |\




C. 20 to 50%
|\ |\ |\




d. 10 to 15% - CORRECT ANSWERS ✔✔a
|\ |\ |\ |\ |\ |\ |\




Which of the following is true about pumping scum from a
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



primary clarifier?
|\ |\




a. Pumping scum is less problematic during cold weather
|\ |\ |\ |\ |\ |\ |\ |\




b. Scum rarely leads to plugged pipelines due to its
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



viscous nature |\




c. Scum causes more piping problems than other
|\ |\ |\ |\ |\ |\ |\ |\



substances pumped at a wastewater treatment plant. |\ |\ |\ |\ |\ |\




d. Scum causes the least amount of piping problems
|\ |\ |\ |\ |\ |\ |\ |\ |\



among all the substances pumped at a wastewater
|\ |\ |\ |\ |\ |\ |\ |\



treatment plant pumped at a wastewater treatment plant
|\ |\ |\ |\ |\ |\ |\



- CORRECT ANSWERS ✔✔c
|\ |\ |\ |\

,What might cause thick billows of white sudsy foam in the
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



aeration tank?
|\ |\




a. MLSS is too high
|\ |\ |\ |\




b. Temperature in the aeration tank is too low
|\ |\ |\ |\ |\ |\ |\ |\




c. Old sludge
|\ |\




d. MLSS is too low - CORRECT ANSWERS ✔✔d
|\ |\ |\ |\ |\ |\ |\ |\




What does the "M" in F/M ratio represent?
|\ |\ |\ |\ |\ |\ |\




a. MLSS in the aeration tank
|\ |\ |\ |\ |\




b. The influent BOD loading rate into the aeration tank
|\ |\ |\ |\ |\ |\ |\ |\ |\




c. The mixed liquor volatile suspended solids in the
|\ |\ |\ |\ |\ |\ |\ |\ |\



aeration tank |\




d. The mass of inorganic solids in the aeration tank -
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



CORRECT ANSWERS ✔✔c |\ |\




In general- how will warmer temperature affect the
|\ |\ |\ |\ |\ |\ |\ |\



settling rate of solids in a clarifier?
|\ |\ |\ |\ |\ |\




a. Decrease the settling rate
|\ |\ |\ |\




b. Increase the settling rate
|\ |\ |\ |\

, c. Temperature will not affect the settling rate
|\ |\ |\ |\ |\ |\ |\




d. Worsens the settling rate - CORRECT ANSWERS ✔✔b
|\ |\ |\ |\ |\ |\ |\ |\




What could happen if the digester gas is mixed with air
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\



(85 TO 95% by volume)?
|\ |\ |\ |\




a. Cause an explosion
|\ |\ |\




b. Improve efficiency of digestion
|\ |\ |\ |\




c. The bacteria will become aerobic and increase VSR
|\ |\ |\ |\ |\ |\ |\ |\




d. The digester becomes safer to operate due to less toxic
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



gas in the system. - CORRECT ANSWERS ✔✔a
|\ |\ |\ |\ |\ |\ |\ |\




How will algae impact the chlorine demand in the pond
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\



effluent?


a. Slightly decreases chlorine demand
|\ |\ |\ |\




b. Does not affect chlorine demand
|\ |\ |\ |\ |\




c. Significantly decreases chlorine demand
|\ |\ |\ |\




d. Increases chlorine demand - CORRECT ANSWERS ✔✔d
|\ |\ |\ |\ |\ |\ |\




Which of the following is true about a positive
|\ |\ |\ |\ |\ |\ |\ |\ |\



displacement pump? |\