WASTEWATER TREATMENT LEVEL II PRACTICE TEST
QUESTIONS WITH COMPLETE SOLUTIONS
1) Pathogens are best described as _______:
a) Disease-causing organisms
b) An acute case of indigestion
c) An indicator test for viruses
d) Cancer-producing agents -- Correct Answer ✔✔ a) Disease-causing
organisms
2) What is the normal operating velocity through a screen channel in feet per second?
a) 1.0 ft/sec
b) 1.5 ft/sec
c) 2.0 ft/sec
d) 2.5 ft/sec -- Correct Answer ✔✔ b) 1.5 ft/sec
3) What is the normal operating velocity through a grit chamber in feet per second?
a) 1.0 ft/sec
b) 2.0 ft/sec
c) 5.0 ft/sec
d) None of the above -- Correct Answer ✔✔ a) 1.0 ft/sec
4) What is the average time for wastewater in a primary clarifier?
a) 1 hour
, b) 2 hour
c) 3 hour
d) 4 hour -- Correct Answer ✔✔ b) 2 hour
5) The color of biofilm on a rotating contactor would appear what colour under
normal operating conditions?
a) Dark brown
b) Brown
c) Grey
d) Green -- Correct Answer ✔✔ c) Grey
6) The main biological process for activated sludge happens in the:
a) Preliminary treatment
b) Primary treatment
c) Secondary treatment
d) Tertiary treatment -- Correct Answer ✔✔ c) Secondary treatment
7) The purpose of a lantern ring is to _______:
a) Distribute lubrication to the packing
b) Prevent water from getting into the stuffing box
c) Seal the low-pressure zone from the high-pressure zone
d) Hold the shaft in place -- Correct Answer ✔✔ a) Distribute lubrication to
the packing
8) Which type of flowmeter should be used for wastewater with high flows?
a) Rotameter
b) Head meter
c) Magmeter
d) Oscillating meter -- Correct Answer ✔✔ c) Magmeter
, 9) The mixture of organisms and solids in water that is removed form the settling tank
is called:
a) Mixed liquor
b) Mixed liquor suspended solids
c) Supernatant
d) Subnatant -- Correct Answer ✔✔ b) Mixed liquor suspended solids
10) How many days would it take to fill a lagoon that is 45 m long, 20 m wide and 3 m
deep, if the flow rate is 500 L/min?
a) 2.8 days
b) 3.8 days
c) 4.8 days
d) 5 days -- Correct Answer ✔✔ b) 3.8 days
11) The main "workers' in the activated sludge process are:
a) Bacteria
b) Viruses
c) Protozoans
d) Fungi -- Correct Answer ✔✔ a) Bacteria
12) What is the main reason wastewater treatment plants aim to remove nutrients from
the eluent prior to discharge?
a) Stratification
b) Eutrophication
c) Nitrification
d) Thermal turn over -- Correct Answer ✔✔ b) Eutrophication
13) This solids treatment process usually has a retention time of 20 days:
a) Gravity thicker
b) Aerobic digestion
c) Lime stabilization
d) Waste stabilization pond -- Correct Answer ✔✔ b) Aerobic digestion
QUESTIONS WITH COMPLETE SOLUTIONS
1) Pathogens are best described as _______:
a) Disease-causing organisms
b) An acute case of indigestion
c) An indicator test for viruses
d) Cancer-producing agents -- Correct Answer ✔✔ a) Disease-causing
organisms
2) What is the normal operating velocity through a screen channel in feet per second?
a) 1.0 ft/sec
b) 1.5 ft/sec
c) 2.0 ft/sec
d) 2.5 ft/sec -- Correct Answer ✔✔ b) 1.5 ft/sec
3) What is the normal operating velocity through a grit chamber in feet per second?
a) 1.0 ft/sec
b) 2.0 ft/sec
c) 5.0 ft/sec
d) None of the above -- Correct Answer ✔✔ a) 1.0 ft/sec
4) What is the average time for wastewater in a primary clarifier?
a) 1 hour
, b) 2 hour
c) 3 hour
d) 4 hour -- Correct Answer ✔✔ b) 2 hour
5) The color of biofilm on a rotating contactor would appear what colour under
normal operating conditions?
a) Dark brown
b) Brown
c) Grey
d) Green -- Correct Answer ✔✔ c) Grey
6) The main biological process for activated sludge happens in the:
a) Preliminary treatment
b) Primary treatment
c) Secondary treatment
d) Tertiary treatment -- Correct Answer ✔✔ c) Secondary treatment
7) The purpose of a lantern ring is to _______:
a) Distribute lubrication to the packing
b) Prevent water from getting into the stuffing box
c) Seal the low-pressure zone from the high-pressure zone
d) Hold the shaft in place -- Correct Answer ✔✔ a) Distribute lubrication to
the packing
8) Which type of flowmeter should be used for wastewater with high flows?
a) Rotameter
b) Head meter
c) Magmeter
d) Oscillating meter -- Correct Answer ✔✔ c) Magmeter
, 9) The mixture of organisms and solids in water that is removed form the settling tank
is called:
a) Mixed liquor
b) Mixed liquor suspended solids
c) Supernatant
d) Subnatant -- Correct Answer ✔✔ b) Mixed liquor suspended solids
10) How many days would it take to fill a lagoon that is 45 m long, 20 m wide and 3 m
deep, if the flow rate is 500 L/min?
a) 2.8 days
b) 3.8 days
c) 4.8 days
d) 5 days -- Correct Answer ✔✔ b) 3.8 days
11) The main "workers' in the activated sludge process are:
a) Bacteria
b) Viruses
c) Protozoans
d) Fungi -- Correct Answer ✔✔ a) Bacteria
12) What is the main reason wastewater treatment plants aim to remove nutrients from
the eluent prior to discharge?
a) Stratification
b) Eutrophication
c) Nitrification
d) Thermal turn over -- Correct Answer ✔✔ b) Eutrophication
13) This solids treatment process usually has a retention time of 20 days:
a) Gravity thicker
b) Aerobic digestion
c) Lime stabilization
d) Waste stabilization pond -- Correct Answer ✔✔ b) Aerobic digestion
