Prince Edward Island Wastewater Operator Level 2 Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf
- What is the primary purpose of a grit chamber in wastewater
treatment?
a) To remove dissolved organic matter
b) To remove suspended solids
c) To remove heavy inorganic particles
d) To disinfect the wastewater
Rationale: Grit chambers are designed to remove sand, gravel, and other
heavy inorganic solids to prevent damage and abrasion to downstream equipment. 1 / 4
- The most common method for measuring flow in a wastewater
treatment plant is:
a) Weir
b) Pitot tube
c) Parshall flume
d) Orifice plate
Rationale: Parshall flumes are widely used because they provide accurate
flow measurements with minimal maintenance.
- What is the primary function of a primary clarifier?
a) Remove dissolved nutrients
b) Settle suspended solids
c) Disinfect the water
d) Oxidize organic matter
Rationale: Primary clarifiers allow suspended solids to settle out by gravity
before the wastewater moves to secondary treatment.
- Which process is used to biologically remove nitrogen in wastewater?
a) Filtration
b) Nitrification and denitrification
c) Chlorination
d) Coagulation
Rationale: Nitrification converts ammonia to nitrate, and denitrification
converts nitrate to nitrogen gas, effectively removing nitrogen. 2 / 4
- What is the typical detention time for a primary clarifier?
- 10–15 minutes
- 1–2 hours
- 6–8 hours
- 24 hours
Rationale: Primary clarifiers typically have a detention time of 1–2 hours to
allow solids to settle effectively.
- Which microorganism is most important for biological treatment of
wastewater?
a) Viruses
b) Protozoa
c) Bacteria
d) Algae
Rationale: Bacteria are the main organisms responsible for decomposing
organic matter in biological treatment processes.
7. Activated sludge is classified as:
a) Chemical treatment
b) Biological treatment
c) Physical treatment
d) Disinfection
Rationale: Activated sludge is a biological process that uses
microorganisms to remove organic matter from wastewater. 3 / 4
8. The main goal of secondary treatment is to:
a) Remove grit
b) Remove fats, oils, and grease
c) Remove dissolved and suspended organic matter
d) Remove heavy metals
Rationale: Secondary treatment focuses on reducing BOD, suspended
solids, and other biodegradable organics.
- Which parameter indicates the amount of oxygen required by
microorganisms to decompose organic matter?
a) COD
b) TSS
c) BOD
- pH
Rationale: BOD (Biochemical Oxygen Demand) measures the oxygen
needed by microorganisms to break down organic matter.
10. A sudden drop in pH of influent wastewater can cause:
a) Increased BOD removal
b) Enhanced nitrification
c) Shock to biological processes
d) Faster sedimentation
Rationale: Sudden pH changes can inhibit microbial activity and disturb
biological treatment processes.
- / 4