West Virginia Wastewater Class II Operator Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf
- Which of the following is the primary purpose of a grit chamber in
- Remove organic matter
- Remove dissolved solids
- Remove heavy inorganic particles
- Reduce bacteria
wastewater treatment?
Rationale: Grit chambers are designed to remove sand, gravel, and
other heavy inorganic particles before they damage downstream equipment. 1 / 4
- In activated sludge systems, what is the primary function of aeration?
- Settle solids
- Provide oxygen for microbial activity
- Remove grit
- Disinfect effluent
Rationale: Aeration supplies oxygen to microorganisms, enabling
them to break down organic pollutants.
- The ideal pH range for most biological wastewater treatment
processes is:
A. 4.5–5.5
B. 5.5–6.5
C. 9.0–10.0
D. 6.5–8.5
Rationale: Most microorganisms thrive in a near-neutral pH
environment, typically between 6.5 and 8.5.
4. Sludge digestion primarily reduces:
- Nitrogen content
- Organic solids
- Heavy metals
- Phosphorus
Rationale: Digestion breaks down organic solids in sludge, reducing
volume and stabilizing it. 2 / 4
- Which process is most effective for removing ammonia from
- Chlorination
- Nitrification
- Sedimentation
- Coagulation
wastewater?
Rationale: Nitrification biologically converts ammonia to nitrite and
nitrate, removing it from wastewater.
6. The primary reason for using a bar screen is to:
- Remove bacteria
- Reduce BOD
- Remove large solids
- Settle grit
Rationale: Bar screens trap large objects such as sticks, rags, and
plastics to prevent equipment damage.
- What is the main function of primary sedimentation tanks?
- Reduce BOD biologically
- Remove settleable solids
- Remove dissolved nutrients
- Aerate wastewater
Rationale: Primary sedimentation tanks allow heavy solids to settle
out by gravity. 3 / 4
8. The term BOD stands for:
- Biological Oxidation Demand
- Biochemical Oxygen Demand
- Biological Organic Decomposition
- Basic Oxidation Design
Rationale: BOD measures the amount of oxygen microorganisms
consume while decomposing organic matter.
9. A sudden increase in toxic industrial wastewater can cause:
- Increased nitrification
- Improved settling
- Shock load leading to treatment failure
- Increased sludge digestion
Rationale: Shock loads of toxic substances can kill microorganisms
and disrupt biological treatment.
- Which of the following is considered a suspended solids removal
- Chlorination
- Sedimentation
- Filtration
- Coagulation
process?
Rationale: Sedimentation allows suspended solids to settle out of
wastewater.
- / 4