.
,1. What is the primary purpose of coagulation during drinking water
treatment?
A. Kill bacteria
B. Destabilize suspended particles so they can form larger flocs
C. Increase water pH
D. Remove dissolved oxygen
Answer: B
Explanation: Coagulation involves adding chemicals such as alum or ferric
salts to neutralize the electrical charges on suspended particles, allowing them
to combine into larger flocs for removal during flocculation and sedimentation.
2. Which disinfectant leaves a measurable residual throughout the
distribution system?
A. Ultraviolet (UV) light
B. Ozone
C. Chlorine
,D. Activated carbon
Answer: C
Explanation: Chlorine provides a disinfectant residual that continues protecting
water from microbial contamination as it travels through the distribution system.
3. Which water quality parameter most directly affects chlorine
disinfection efficiency?
A. Turbidity
B. Water temperature
C. pH
D. All of the above
Answer: D
Explanation: Turbidity can shield microorganisms, lower temperatures slow
disinfection reactions, and higher pH reduces the effectiveness of free chlorine.
4. What is the main purpose of flocculation?
A. Break apart particles
, B. Promote the formation of larger, settleable flocs
C. Increase dissolved oxygen
D. Raise alkalinity
Answer: B
Explanation: Gentle mixing encourages destabilized particles to collide and
form larger flocs that can be removed more efficiently during sedimentation.
5. Which process primarily removes dissolved organic compounds
responsible for taste and odor?
A. Activated carbon adsorption
B. Screening
C. Sedimentation
D. Aeration alone
Answer: A
Explanation: Activated carbon effectively adsorbs many dissolved organic
compounds that cause objectionable tastes, odors, and certain contaminants.
,1. What is the primary purpose of coagulation during drinking water
treatment?
A. Kill bacteria
B. Destabilize suspended particles so they can form larger flocs
C. Increase water pH
D. Remove dissolved oxygen
Answer: B
Explanation: Coagulation involves adding chemicals such as alum or ferric
salts to neutralize the electrical charges on suspended particles, allowing them
to combine into larger flocs for removal during flocculation and sedimentation.
2. Which disinfectant leaves a measurable residual throughout the
distribution system?
A. Ultraviolet (UV) light
B. Ozone
C. Chlorine
,D. Activated carbon
Answer: C
Explanation: Chlorine provides a disinfectant residual that continues protecting
water from microbial contamination as it travels through the distribution system.
3. Which water quality parameter most directly affects chlorine
disinfection efficiency?
A. Turbidity
B. Water temperature
C. pH
D. All of the above
Answer: D
Explanation: Turbidity can shield microorganisms, lower temperatures slow
disinfection reactions, and higher pH reduces the effectiveness of free chlorine.
4. What is the main purpose of flocculation?
A. Break apart particles
, B. Promote the formation of larger, settleable flocs
C. Increase dissolved oxygen
D. Raise alkalinity
Answer: B
Explanation: Gentle mixing encourages destabilized particles to collide and
form larger flocs that can be removed more efficiently during sedimentation.
5. Which process primarily removes dissolved organic compounds
responsible for taste and odor?
A. Activated carbon adsorption
B. Screening
C. Sedimentation
D. Aeration alone
Answer: A
Explanation: Activated carbon effectively adsorbs many dissolved organic
compounds that cause objectionable tastes, odors, and certain contaminants.
