Louisiana Water Treatment Operator Level I
Exam Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
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1.
The primary purpose of coagulation in water treatment is to:
A. Soften water
B. Destabilize suspended particles
C. Disinfect the water
D. Remove dissolved gases
Coagulation neutralizes particle charges so they can clump together.
2.
Which chemical is most commonly used as a coagulant?
A. Chlorine
B. Aluminum sulfate (alum)
C. Lime
D. Carbon dioxide
Alum is widely used for coagulation in surface water treatment.
3.
,The pH range where alum works best is:
A. 3–4
B. 5–6
C. 6–7
D. 9–10
Alum is most effective in slightly acidic to neutral conditions.
4.
The purpose of flocculation is to:
A. Kill pathogens
B. Remove hardness
C. Form larger, settleable floc particles
D. Increase alkalinity
Gentle mixing allows microfloc to grow into settleable particles.
5.
A flash mixer is used to:
A. Rapidly and evenly disperse coagulant
B. Remove sediment
C. Increase alkalinity
D. Measure turbidity
Flash mixing ensures fast chemical dispersion.
6.
,In sedimentation, particles are removed primarily by:
A. Adsorption
B. Gravity settling
C. Ion exchange
D. Disinfection
Sedimentation uses gravity to remove heavy floc.
7.
Which factor most increases the efficiency of sedimentation?
A. Higher water temperature
B. Lower flow velocity
C. Higher pH
D. High chlorine residual
Lower velocity improves settling time.
8.
Filtration removes:
A. Viruses only
B. Dissolved solids
C. Suspended and particulate matter
D. Color only
Filtration targets particles not removed earlier.
9.
, The most common filter media in rapid sand filters is:
A. Anthracite only
B. Gravel only
C. Sand and anthracite
D. Lime and sand
Dual-media filters improve performance.
10.
Backwashing a filter is done to:
A. Adjust pH
B. Remove accumulated solids
C. Add disinfectant
D. Reduce turbidity of source water
Backwashing flushes out captured particles.
11.
What does a turbidity meter measure?
A. pH
B. Color
C. Cloudiness of water
D. Chlorine demand
Turbidity is a measure of suspended particles.
12.
Exam Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1.
The primary purpose of coagulation in water treatment is to:
A. Soften water
B. Destabilize suspended particles
C. Disinfect the water
D. Remove dissolved gases
Coagulation neutralizes particle charges so they can clump together.
2.
Which chemical is most commonly used as a coagulant?
A. Chlorine
B. Aluminum sulfate (alum)
C. Lime
D. Carbon dioxide
Alum is widely used for coagulation in surface water treatment.
3.
,The pH range where alum works best is:
A. 3–4
B. 5–6
C. 6–7
D. 9–10
Alum is most effective in slightly acidic to neutral conditions.
4.
The purpose of flocculation is to:
A. Kill pathogens
B. Remove hardness
C. Form larger, settleable floc particles
D. Increase alkalinity
Gentle mixing allows microfloc to grow into settleable particles.
5.
A flash mixer is used to:
A. Rapidly and evenly disperse coagulant
B. Remove sediment
C. Increase alkalinity
D. Measure turbidity
Flash mixing ensures fast chemical dispersion.
6.
,In sedimentation, particles are removed primarily by:
A. Adsorption
B. Gravity settling
C. Ion exchange
D. Disinfection
Sedimentation uses gravity to remove heavy floc.
7.
Which factor most increases the efficiency of sedimentation?
A. Higher water temperature
B. Lower flow velocity
C. Higher pH
D. High chlorine residual
Lower velocity improves settling time.
8.
Filtration removes:
A. Viruses only
B. Dissolved solids
C. Suspended and particulate matter
D. Color only
Filtration targets particles not removed earlier.
9.
, The most common filter media in rapid sand filters is:
A. Anthracite only
B. Gravel only
C. Sand and anthracite
D. Lime and sand
Dual-media filters improve performance.
10.
Backwashing a filter is done to:
A. Adjust pH
B. Remove accumulated solids
C. Add disinfectant
D. Reduce turbidity of source water
Backwashing flushes out captured particles.
11.
What does a turbidity meter measure?
A. pH
B. Color
C. Cloudiness of water
D. Chlorine demand
Turbidity is a measure of suspended particles.
12.
