Water Treatment Operator Class C Licensing
Exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
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1. What is the primary purpose of coagulation in water treatment?
A. Disinfection
B. Particle destabilization
C. pH adjustment
D. Fluoridation
Answer: B
Rationale: Coagulation neutralizes charges on suspended particles so
they can clump together.
2. Which chemical is commonly used as a coagulant?
A. Chlorine
B. Alum
C. Lime
,D. Soda ash
Answer: B
Rationale: Alum (aluminum sulfate) is widely used for coagulation.
3. What process follows coagulation?
A. Filtration
B. Sedimentation
C. Disinfection
D. Fluoridation
Answer: B
Rationale: Floc particles settle out during sedimentation after
coagulation/flocculation.
4. What is the main purpose of filtration?
A. Kill bacteria
B. Remove suspended particles
C. Adjust pH
D. Add chemicals
Answer: B
Rationale: Filtration removes remaining suspended solids from water.
,5. Which disinfectant is most commonly used in water treatment?
A. Oxygen
B. Chlorine
C. Nitrogen
D. Hydrogen peroxide
Answer: B
Rationale: Chlorine is widely used due to effectiveness and residual
protection.
6. What does turbidity measure?
A. pH level
B. Water hardness
C. Cloudiness of water
D. Chlorine content
Answer: C
Rationale: Turbidity indicates suspended particles causing cloudiness.
7. What is the ideal pH range for drinking water?
, A. 0–3
B. 4–5
C. 6.5–8.5
D. 9–12
Answer: C
Rationale: Safe drinking water is typically between 6.5 and 8.5.
8. What is sedimentation?
A. Chemical mixing
B. Particle settling
C. Disinfection process
D. Filtration method
Answer: B
Rationale: Sedimentation allows heavier particles to settle by gravity.
9. What is flocculation?
A. Adding chlorine
B. Gentle mixing to form floc
C. Removing bacteria
D. Filtering water
Exam Questions and Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. What is the primary purpose of coagulation in water treatment?
A. Disinfection
B. Particle destabilization
C. pH adjustment
D. Fluoridation
Answer: B
Rationale: Coagulation neutralizes charges on suspended particles so
they can clump together.
2. Which chemical is commonly used as a coagulant?
A. Chlorine
B. Alum
C. Lime
,D. Soda ash
Answer: B
Rationale: Alum (aluminum sulfate) is widely used for coagulation.
3. What process follows coagulation?
A. Filtration
B. Sedimentation
C. Disinfection
D. Fluoridation
Answer: B
Rationale: Floc particles settle out during sedimentation after
coagulation/flocculation.
4. What is the main purpose of filtration?
A. Kill bacteria
B. Remove suspended particles
C. Adjust pH
D. Add chemicals
Answer: B
Rationale: Filtration removes remaining suspended solids from water.
,5. Which disinfectant is most commonly used in water treatment?
A. Oxygen
B. Chlorine
C. Nitrogen
D. Hydrogen peroxide
Answer: B
Rationale: Chlorine is widely used due to effectiveness and residual
protection.
6. What does turbidity measure?
A. pH level
B. Water hardness
C. Cloudiness of water
D. Chlorine content
Answer: C
Rationale: Turbidity indicates suspended particles causing cloudiness.
7. What is the ideal pH range for drinking water?
, A. 0–3
B. 4–5
C. 6.5–8.5
D. 9–12
Answer: C
Rationale: Safe drinking water is typically between 6.5 and 8.5.
8. What is sedimentation?
A. Chemical mixing
B. Particle settling
C. Disinfection process
D. Filtration method
Answer: B
Rationale: Sedimentation allows heavier particles to settle by gravity.
9. What is flocculation?
A. Adding chlorine
B. Gentle mixing to form floc
C. Removing bacteria
D. Filtering water
