WATER TREATMENT AWWA QUESTIONS GRADES 1 AND 2:
TREATMENT PROCESS COMPREHENSIVE QUESTIONS AND
VERIFIED DETAILED SOLUTIONS ( MULTIPLE CHOICES) |
100% CORRECT!!
What must the effluent NTU for a slow sand filter be kept at during
operation? Correct Answers Less than 1.0 NTU
When water is added too fast to this treatment chemical, it will generate
heat and splattering of the chemical. Correct Answers Sulfuric acid
In the lime-softening process, besides CaCO3 being precipitated, what
other carbonate hardness chemical is precipitated? Correct Answers
Magnesium hydroxide
Dry alum has a formula of Correct Answers Al2(SO4)3 · 14H2O
What is the most common chemical used for pH and alkalinity
adjustment? Correct Answers Lime
After breakpoint chlorination, what may remain besides the free
chlorine? Correct Answers Chloroorganics
Although algae do not typically pose a health concern, some do produce
__________ that can be a concern. Other problems they frequently
cause in regard to treatment are __________. Correct Answers
neurotoxins and hepatoxins, tastes and odors and filter-clogging
,The oxidation process using chlorine will also consume Correct
Answers alkalinity
Dry chemicals should be in solution before mixing them with the water
to be treated. What water is recommended to mix the dry chemical in
some cases to avoid precipitates? Correct Answers Softened water
How are manganese greensand beds regenerated? Correct Answers
Backwashed with permanganate solution
Once breakpoint chlorination has been reached, what percentage of the
original reducing agents are typically still present in a particular water
sample? Correct Answers 0%
The most preferable method of removing manganese is by using Correct
Answers potassium permanganate.
When iron alone is treated using manganese greensand filters, the
chlorine feed rate should be about Correct Answers 1.0 to 1.2 times the
iron concentration.
What problem can be solved in a sedimentation basin by recycling some
previously settled sludge? Correct Answers Slow floc formation
To eliminate hydrogen sulfide (H2S), the pH of the water should be
lowered to ____ or less before beginning aeration. Correct Answers 6.0
, What factor will make chlorination successful? Correct Answers Higher
concentration
How can an operator compensate for low temperature water and thus
slower floc formation when using alum? Correct Answers Increase alum
dosage
What is (are) the combined chlorine residual(s) at pH values ranging
from 6.5 to 8.5? Correct Answers Monochloramine and dichloramine
What is an advantage for installing a pressure filter for a small water
system? Correct Answers Air binding will not occur
How is magnesium noncarbonate hardness removed? Correct Answers
With lime, then soda ash
When adding chlorine and sodium hydroxide to water containing
manganese, the oxidation works best in a pH range of Correct Answers
6 to 10
Why can rapid sand filters handle higher filtration rates compared to
slow sand filters? Correct Answers Coarser sand
TREATMENT PROCESS COMPREHENSIVE QUESTIONS AND
VERIFIED DETAILED SOLUTIONS ( MULTIPLE CHOICES) |
100% CORRECT!!
What must the effluent NTU for a slow sand filter be kept at during
operation? Correct Answers Less than 1.0 NTU
When water is added too fast to this treatment chemical, it will generate
heat and splattering of the chemical. Correct Answers Sulfuric acid
In the lime-softening process, besides CaCO3 being precipitated, what
other carbonate hardness chemical is precipitated? Correct Answers
Magnesium hydroxide
Dry alum has a formula of Correct Answers Al2(SO4)3 · 14H2O
What is the most common chemical used for pH and alkalinity
adjustment? Correct Answers Lime
After breakpoint chlorination, what may remain besides the free
chlorine? Correct Answers Chloroorganics
Although algae do not typically pose a health concern, some do produce
__________ that can be a concern. Other problems they frequently
cause in regard to treatment are __________. Correct Answers
neurotoxins and hepatoxins, tastes and odors and filter-clogging
,The oxidation process using chlorine will also consume Correct
Answers alkalinity
Dry chemicals should be in solution before mixing them with the water
to be treated. What water is recommended to mix the dry chemical in
some cases to avoid precipitates? Correct Answers Softened water
How are manganese greensand beds regenerated? Correct Answers
Backwashed with permanganate solution
Once breakpoint chlorination has been reached, what percentage of the
original reducing agents are typically still present in a particular water
sample? Correct Answers 0%
The most preferable method of removing manganese is by using Correct
Answers potassium permanganate.
When iron alone is treated using manganese greensand filters, the
chlorine feed rate should be about Correct Answers 1.0 to 1.2 times the
iron concentration.
What problem can be solved in a sedimentation basin by recycling some
previously settled sludge? Correct Answers Slow floc formation
To eliminate hydrogen sulfide (H2S), the pH of the water should be
lowered to ____ or less before beginning aeration. Correct Answers 6.0
, What factor will make chlorination successful? Correct Answers Higher
concentration
How can an operator compensate for low temperature water and thus
slower floc formation when using alum? Correct Answers Increase alum
dosage
What is (are) the combined chlorine residual(s) at pH values ranging
from 6.5 to 8.5? Correct Answers Monochloramine and dichloramine
What is an advantage for installing a pressure filter for a small water
system? Correct Answers Air binding will not occur
How is magnesium noncarbonate hardness removed? Correct Answers
With lime, then soda ash
When adding chlorine and sodium hydroxide to water containing
manganese, the oxidation works best in a pH range of Correct Answers
6 to 10
Why can rapid sand filters handle higher filtration rates compared to
slow sand filters? Correct Answers Coarser sand
