Minnesota Water Treatment
Engineering Specialist Exam Practice
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. To disinfect water
B. To destabilize suspended particles for removal
C. To increase water hardness
D. To adjust pH
Rationale: Coagulation neutralizes particle charges so they can
clump together for easier removal in later processes.
2. Which chemical is most commonly used as a coagulant?
A. Sodium chloride
B. Aluminum sulfate (alum)
C. Calcium carbonate
D. Chlorine
, Rationale: Alum is widely used due to its effectiveness and cost
efficiency in destabilizing colloidal particles.
3. What process follows coagulation in conventional water treatment?
A. Disinfection
B. Flocculation
C. Filtration
D. Sedimentation
Rationale: Flocculation gently mixes water to form larger particles
(flocs) after coagulation.
4. What is the main purpose of sedimentation?
A. Add oxygen to water
B. Remove dissolved salts
C. Allow suspended solids to settle out by gravity
D. Increase chlorine contact time
Rationale: Sedimentation relies on gravity to remove floc particles
from water.
5. Which unit process removes fine particles using porous media?
A. Flocculation
B. Sedimentation
C. Filtration
D. Coagulation
Rationale: Filtration removes remaining suspended particles after
sedimentation.
, 6. What is the most common disinfectant used in municipal water
systems?
A. Ozone
B. UV light
C. Chlorine
D. Ammonia
Rationale: Chlorine is widely used due to its effectiveness and
residual protection.
7. What is the purpose of a chlorine residual?
A. Increase turbidity
B. Improve taste
C. Maintain ongoing disinfection in distribution system
D. Remove hardness
Rationale: Residual chlorine prevents microbial regrowth in
pipelines.
8. Which factor most affects coagulation efficiency?
A. Pipe diameter
B. Water color
C. pH level
D. Temperature only
Rationale: pH significantly affects coagulant charge neutralization.
9. What does turbidity measure?
A. Dissolved minerals
Engineering Specialist Exam Practice
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. To disinfect water
B. To destabilize suspended particles for removal
C. To increase water hardness
D. To adjust pH
Rationale: Coagulation neutralizes particle charges so they can
clump together for easier removal in later processes.
2. Which chemical is most commonly used as a coagulant?
A. Sodium chloride
B. Aluminum sulfate (alum)
C. Calcium carbonate
D. Chlorine
, Rationale: Alum is widely used due to its effectiveness and cost
efficiency in destabilizing colloidal particles.
3. What process follows coagulation in conventional water treatment?
A. Disinfection
B. Flocculation
C. Filtration
D. Sedimentation
Rationale: Flocculation gently mixes water to form larger particles
(flocs) after coagulation.
4. What is the main purpose of sedimentation?
A. Add oxygen to water
B. Remove dissolved salts
C. Allow suspended solids to settle out by gravity
D. Increase chlorine contact time
Rationale: Sedimentation relies on gravity to remove floc particles
from water.
5. Which unit process removes fine particles using porous media?
A. Flocculation
B. Sedimentation
C. Filtration
D. Coagulation
Rationale: Filtration removes remaining suspended particles after
sedimentation.
, 6. What is the most common disinfectant used in municipal water
systems?
A. Ozone
B. UV light
C. Chlorine
D. Ammonia
Rationale: Chlorine is widely used due to its effectiveness and
residual protection.
7. What is the purpose of a chlorine residual?
A. Increase turbidity
B. Improve taste
C. Maintain ongoing disinfection in distribution system
D. Remove hardness
Rationale: Residual chlorine prevents microbial regrowth in
pipelines.
8. Which factor most affects coagulation efficiency?
A. Pipe diameter
B. Water color
C. pH level
D. Temperature only
Rationale: pH significantly affects coagulant charge neutralization.
9. What does turbidity measure?
A. Dissolved minerals
