PMT 108 Principles of water Test 3
Questions With Complete Solutions
Course
PMT 108
1. What is the primary purpose of water treatment in municipal water systems?
A) To increase the aesthetic value of water
B) To remove harmful microorganisms and contaminants
C) To add minerals for taste
D) To decrease the temperature of the water
Answer:
B) To remove harmful microorganisms and contaminants
The main purpose of water treatment is to ensure that the water is safe for human consumption
by removing harmful pathogens and other contaminants.
2. Which of the following is NOT a common method used in water treatment?
A) Filtration
B) Chlorination
C) Reverse osmosis
D) Distillation of wastewater
Answer:
D) Distillation of wastewater
While distillation is a water treatment method, it is typically not used in municipal water
treatment due to its high cost and inefficiency in treating large volumes of water. Filtration,
chlorination, and reverse osmosis are common methods used in water treatment.
3. The process of coagulation in water treatment is used to:
A) Remove dissolved minerals from the water
B) Remove suspended particles and bacteria
C) Add chlorine to disinfect the water
D) Raise the pH of the water
Answer:
B) Remove suspended particles and bacteria
Coagulation involves adding chemicals (coagulants) to water to clump suspended particles and
bacteria together into larger aggregates, making them easier to remove during filtration.
,4. Which chemical is commonly used in the coagulation process in water
treatment?
A) Sodium hypochlorite
B) Aluminum sulfate (alum)
C) Calcium hydroxide
D) Sodium carbonate
Answer:
B) Aluminum sulfate (alum)
Aluminum sulfate (alum) is commonly used as a coagulant in water treatment to help remove
particles and impurities from the water.
5. In water treatment, the purpose of filtration is to:
A) Remove bacteria
B) Remove dissolved chemicals
C) Remove larger suspended particles
D) Add chlorine to disinfect water
Answer:
C) Remove larger suspended particles
Filtration removes larger particles, such as dirt, debris, and some microorganisms, from the
water. However, it does not remove dissolved chemicals or bacteria, which is why other methods
(like disinfection) are used in conjunction.
6. What is the primary disinfectant used in most municipal water systems?
A) Chlorine
B) Ozone
C) Ultraviolet (UV) light
D) Hydrogen peroxide
Answer:
A) Chlorine
Chlorine is the most commonly used disinfectant in municipal water systems. It effectively kills
bacteria, viruses, and other harmful microorganisms, ensuring the water is safe to drink.
,7. Which of the following describes the reverse osmosis process in water
treatment?
A) Water is passed through a membrane that allows only clean water molecules to pass, while
contaminants are left behind.
B) Water is boiled and then condensed to remove impurities.
C) Water is exposed to ultraviolet light to kill bacteria.
D) Water is filtered through sand and charcoal to remove debris.
Answer:
A) Water is passed through a membrane that allows only clean water molecules to pass,
while contaminants are left behind.
Reverse osmosis uses a semi-permeable membrane to remove impurities, including salts,
minerals, and contaminants, from water.
8. The term "hard water" refers to water that contains high levels of:
A) Oxygen
B) Calcium and magnesium
C) Sodium
D) Chlorine
Answer:
B) Calcium and magnesium
Hard water contains high concentrations of calcium and magnesium ions, which can cause
scaling in pipes and appliances.
9. What is the purpose of adding lime (Ca(OH)₂) during water treatment?
A) To reduce the water's acidity
B) To disinfect the water
C) To soften the water by precipitating calcium and magnesium ions
D) To remove suspended solids
Answer:
C) To soften the water by precipitating calcium and magnesium ions
Lime is added to water to remove hardness (calcium and magnesium) by causing these ions to
precipitate, making the water softer.
, 10. In the water treatment process, what is the purpose of the "flocculation"
step?
A) To remove harmful microorganisms using chemicals
B) To cause the coagulated particles to clump together and settle out of the water
C) To add chlorine for disinfection
D) To filter out suspended particles
Answer:
B) To cause the coagulated particles to clump together and settle out of the water
Flocculation is the process where coagulants help suspended particles form larger clusters
(flocs), which then settle out of the water in the sedimentation stage.
11. What is the purpose of adding chlorine to the water during treatment?
A) To increase the pH of the water
B) To remove suspended solids
C) To disinfect and kill harmful microorganisms
D) To add minerals for taste
Answer:
C) To disinfect and kill harmful microorganisms
Chlorine is primarily used in water treatment to disinfect and kill bacteria, viruses, and other
harmful microorganisms to make water safe for consumption.
12. What does the "turbidity" of water measure?
A) The pH of the water
B) The concentration of dissolved gases in the water
C) The clarity or cloudiness of the water due to suspended particles
D) The temperature of the water
Answer:
C) The clarity or cloudiness of the water due to suspended particles
Turbidity is a measure of the water's clarity, which is affected by the presence of suspended
particles such as dirt, clay, and microorganisms.
13. Which of the following processes helps in the removal of dissolved salts and minerals
from water?
A) Filtration
B) Reverse osmosis
Questions With Complete Solutions
Course
PMT 108
1. What is the primary purpose of water treatment in municipal water systems?
A) To increase the aesthetic value of water
B) To remove harmful microorganisms and contaminants
C) To add minerals for taste
D) To decrease the temperature of the water
Answer:
B) To remove harmful microorganisms and contaminants
The main purpose of water treatment is to ensure that the water is safe for human consumption
by removing harmful pathogens and other contaminants.
2. Which of the following is NOT a common method used in water treatment?
A) Filtration
B) Chlorination
C) Reverse osmosis
D) Distillation of wastewater
Answer:
D) Distillation of wastewater
While distillation is a water treatment method, it is typically not used in municipal water
treatment due to its high cost and inefficiency in treating large volumes of water. Filtration,
chlorination, and reverse osmosis are common methods used in water treatment.
3. The process of coagulation in water treatment is used to:
A) Remove dissolved minerals from the water
B) Remove suspended particles and bacteria
C) Add chlorine to disinfect the water
D) Raise the pH of the water
Answer:
B) Remove suspended particles and bacteria
Coagulation involves adding chemicals (coagulants) to water to clump suspended particles and
bacteria together into larger aggregates, making them easier to remove during filtration.
,4. Which chemical is commonly used in the coagulation process in water
treatment?
A) Sodium hypochlorite
B) Aluminum sulfate (alum)
C) Calcium hydroxide
D) Sodium carbonate
Answer:
B) Aluminum sulfate (alum)
Aluminum sulfate (alum) is commonly used as a coagulant in water treatment to help remove
particles and impurities from the water.
5. In water treatment, the purpose of filtration is to:
A) Remove bacteria
B) Remove dissolved chemicals
C) Remove larger suspended particles
D) Add chlorine to disinfect water
Answer:
C) Remove larger suspended particles
Filtration removes larger particles, such as dirt, debris, and some microorganisms, from the
water. However, it does not remove dissolved chemicals or bacteria, which is why other methods
(like disinfection) are used in conjunction.
6. What is the primary disinfectant used in most municipal water systems?
A) Chlorine
B) Ozone
C) Ultraviolet (UV) light
D) Hydrogen peroxide
Answer:
A) Chlorine
Chlorine is the most commonly used disinfectant in municipal water systems. It effectively kills
bacteria, viruses, and other harmful microorganisms, ensuring the water is safe to drink.
,7. Which of the following describes the reverse osmosis process in water
treatment?
A) Water is passed through a membrane that allows only clean water molecules to pass, while
contaminants are left behind.
B) Water is boiled and then condensed to remove impurities.
C) Water is exposed to ultraviolet light to kill bacteria.
D) Water is filtered through sand and charcoal to remove debris.
Answer:
A) Water is passed through a membrane that allows only clean water molecules to pass,
while contaminants are left behind.
Reverse osmosis uses a semi-permeable membrane to remove impurities, including salts,
minerals, and contaminants, from water.
8. The term "hard water" refers to water that contains high levels of:
A) Oxygen
B) Calcium and magnesium
C) Sodium
D) Chlorine
Answer:
B) Calcium and magnesium
Hard water contains high concentrations of calcium and magnesium ions, which can cause
scaling in pipes and appliances.
9. What is the purpose of adding lime (Ca(OH)₂) during water treatment?
A) To reduce the water's acidity
B) To disinfect the water
C) To soften the water by precipitating calcium and magnesium ions
D) To remove suspended solids
Answer:
C) To soften the water by precipitating calcium and magnesium ions
Lime is added to water to remove hardness (calcium and magnesium) by causing these ions to
precipitate, making the water softer.
, 10. In the water treatment process, what is the purpose of the "flocculation"
step?
A) To remove harmful microorganisms using chemicals
B) To cause the coagulated particles to clump together and settle out of the water
C) To add chlorine for disinfection
D) To filter out suspended particles
Answer:
B) To cause the coagulated particles to clump together and settle out of the water
Flocculation is the process where coagulants help suspended particles form larger clusters
(flocs), which then settle out of the water in the sedimentation stage.
11. What is the purpose of adding chlorine to the water during treatment?
A) To increase the pH of the water
B) To remove suspended solids
C) To disinfect and kill harmful microorganisms
D) To add minerals for taste
Answer:
C) To disinfect and kill harmful microorganisms
Chlorine is primarily used in water treatment to disinfect and kill bacteria, viruses, and other
harmful microorganisms to make water safe for consumption.
12. What does the "turbidity" of water measure?
A) The pH of the water
B) The concentration of dissolved gases in the water
C) The clarity or cloudiness of the water due to suspended particles
D) The temperature of the water
Answer:
C) The clarity or cloudiness of the water due to suspended particles
Turbidity is a measure of the water's clarity, which is affected by the presence of suspended
particles such as dirt, clay, and microorganisms.
13. Which of the following processes helps in the removal of dissolved salts and minerals
from water?
A) Filtration
B) Reverse osmosis
