Advanced Water Treatment Process
Comprehensive Resource To Help You Ace 2026-2027
Includes Frequently Tested Questions With ELABORATED
100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!!
Current Update!!
1. In the lime-soda ash softening process, __________ are used to help gather the __________
into particles that will readily settle out of the water.
- Correct Answer: coagulants, fine calcium and magnesium precipitates
2. Beneath the slime layer of certain iron bacteria in a pipe, what is produced that reduces the
pH and speeds up the corrosion rate?
- Correct Answer: CO2
3. Although there is no fluoride demand like chlorine has, 10% to 30% will be lost during
- Correct Answer: sedimentation and filtration
4. What membrane platform has an operating mode that is exclusively crossflow?
- Correct Answer: Spiral wound
5. According to best practices, tip speed of the last flocculator should be about __________ and
operate in the range of __________.
- Correct Answer: 1.0 ft/s, 0.9 ft/s to 1.3 ft/s
,6. What membrane process would be used to treat brackish waters?
- Correct Answer: Reverse Osmosis
7. What pH is needed to form the magnesium hydroxide precipitate?
- Correct Answer: Above 10.6
8. What is an advantage that coagulants such as ferric sulfate have over alum?
- Correct Answer: They work over a wider pH range.
9. What is the reason that floc particles are carried over a weir in a sedimentation basin?
- Correct Answer: -Improper pH adjustment
-Coagulation chemicals not at the optimum dosage
-Improper hydraulic conditions
10. The ideal alkalinity for manganese greensand filters for the removal of iron and manganese
is __________, as CaCO3.
- Correct Answer: >120 mg/L
11. In variable declining-rate filtration, what is placed in the effluent line of each filter to
prevent excessive flow rates?
- Correct Answer: A flow-restricting orifice plate
12. In general, the adsorption capacity of granular activated carbon is best when removing
- Correct Answer: taste and odor compounds
13. The iron in a corroding pipe releases two electrons at the anode. What will these electrons
combine with in the pipe?
,- Correct Answer: 2 hydrogen (H+) ions to form hydrogen gas
14. What membrane filtration process operates at the lowest pressures and must be
backwashed frequently?
- Correct Answer: Microfiltration
15. The most economical way to dewater sludge is by using
- Correct Answer: lagoons
16. In the lime-soda ash process, what will cause increased solubility of taste- and odor-causing
compounds?
- Correct Answer: Elevated pH values
17. Besides controlling algae by using copper sulfate or powdered activated carbon, what other
method has been occasionally used?
- Correct Answer: Potassium Permanganate
18. To make sure the gravel hasn't shifted or moved up into the sand layer, a metal rod should
be used to probe the filter on a grid system to locate and record the depth to gravel. At a
minimum, how often should this be done?
- Correct Answer: Once per year
19. What membrane process will remove hardness?
- Correct Answer: nanofiltration and reverse osmosis
20. The oxidation of manganese using aeration works best at a minimum pH greater than
- Correct Answer: 10
, 21. When the total dissolved solids (TDS) concentration __________, the solubility of calcium
carbonate __________.
- Correct Answer: increases, increases
22. A limestone contactor is a treatment device that
- Correct Answer: increases pH and alkalinity.
23. What is a disadvantage of using plate or tube settlers?
- Correct Answer: Additional THMs are produced when coagulant chemicals are used.
24. What will sequester iron but will not prevent corrosion because it only masks the corrosion
by-products?
- Correct Answer: Polyphosphates
25. What is the most important physical and chemical mechanism in drinking water filtration?
- Correct Answer: Adsorption
26. In the reverse osmosis (RO) process, pretreatment of feedwater is usually necessary to
prevent premature __________ of the RO membrane.
- Correct Answer: fouling
27. What are the key factor(s) in the operation of a solid-contact basin?
- Correct Answer: mixing speed and sludge blanket
28. What chemical contactor devices used in corrosion control are simple, low-cost, and require
little maintenance, making them especially suitable in small water systems?
- Correct Answer: Limestone Contactors
Comprehensive Resource To Help You Ace 2026-2027
Includes Frequently Tested Questions With ELABORATED
100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!!
Current Update!!
1. In the lime-soda ash softening process, __________ are used to help gather the __________
into particles that will readily settle out of the water.
- Correct Answer: coagulants, fine calcium and magnesium precipitates
2. Beneath the slime layer of certain iron bacteria in a pipe, what is produced that reduces the
pH and speeds up the corrosion rate?
- Correct Answer: CO2
3. Although there is no fluoride demand like chlorine has, 10% to 30% will be lost during
- Correct Answer: sedimentation and filtration
4. What membrane platform has an operating mode that is exclusively crossflow?
- Correct Answer: Spiral wound
5. According to best practices, tip speed of the last flocculator should be about __________ and
operate in the range of __________.
- Correct Answer: 1.0 ft/s, 0.9 ft/s to 1.3 ft/s
,6. What membrane process would be used to treat brackish waters?
- Correct Answer: Reverse Osmosis
7. What pH is needed to form the magnesium hydroxide precipitate?
- Correct Answer: Above 10.6
8. What is an advantage that coagulants such as ferric sulfate have over alum?
- Correct Answer: They work over a wider pH range.
9. What is the reason that floc particles are carried over a weir in a sedimentation basin?
- Correct Answer: -Improper pH adjustment
-Coagulation chemicals not at the optimum dosage
-Improper hydraulic conditions
10. The ideal alkalinity for manganese greensand filters for the removal of iron and manganese
is __________, as CaCO3.
- Correct Answer: >120 mg/L
11. In variable declining-rate filtration, what is placed in the effluent line of each filter to
prevent excessive flow rates?
- Correct Answer: A flow-restricting orifice plate
12. In general, the adsorption capacity of granular activated carbon is best when removing
- Correct Answer: taste and odor compounds
13. The iron in a corroding pipe releases two electrons at the anode. What will these electrons
combine with in the pipe?
,- Correct Answer: 2 hydrogen (H+) ions to form hydrogen gas
14. What membrane filtration process operates at the lowest pressures and must be
backwashed frequently?
- Correct Answer: Microfiltration
15. The most economical way to dewater sludge is by using
- Correct Answer: lagoons
16. In the lime-soda ash process, what will cause increased solubility of taste- and odor-causing
compounds?
- Correct Answer: Elevated pH values
17. Besides controlling algae by using copper sulfate or powdered activated carbon, what other
method has been occasionally used?
- Correct Answer: Potassium Permanganate
18. To make sure the gravel hasn't shifted or moved up into the sand layer, a metal rod should
be used to probe the filter on a grid system to locate and record the depth to gravel. At a
minimum, how often should this be done?
- Correct Answer: Once per year
19. What membrane process will remove hardness?
- Correct Answer: nanofiltration and reverse osmosis
20. The oxidation of manganese using aeration works best at a minimum pH greater than
- Correct Answer: 10
, 21. When the total dissolved solids (TDS) concentration __________, the solubility of calcium
carbonate __________.
- Correct Answer: increases, increases
22. A limestone contactor is a treatment device that
- Correct Answer: increases pH and alkalinity.
23. What is a disadvantage of using plate or tube settlers?
- Correct Answer: Additional THMs are produced when coagulant chemicals are used.
24. What will sequester iron but will not prevent corrosion because it only masks the corrosion
by-products?
- Correct Answer: Polyphosphates
25. What is the most important physical and chemical mechanism in drinking water filtration?
- Correct Answer: Adsorption
26. In the reverse osmosis (RO) process, pretreatment of feedwater is usually necessary to
prevent premature __________ of the RO membrane.
- Correct Answer: fouling
27. What are the key factor(s) in the operation of a solid-contact basin?
- Correct Answer: mixing speed and sludge blanket
28. What chemical contactor devices used in corrosion control are simple, low-cost, and require
little maintenance, making them especially suitable in small water systems?
- Correct Answer: Limestone Contactors
