Frage 1
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Temperature has no effect on the sedimentation rate of a particle.
Frage 2
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Chloramines are toxic to healthy humans.
Frage 3
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If head loss is a problem but breakthrough is limited, larger sized media may be appropriate.
Frage 4
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A slow sand filter should be backwashed when the head loss through the filter becomes excessive.
Frage 5
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Coagulation and flocculation are used to remove materials, especially non-settleable solids and color.
Frage 6
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The inlet zone of a sedimentation basin is designed to minimize velocities near the bottom of the basin to prevent scouring.
Frage 7
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Smooth circular particles will settle slower than irregular particles.
Frage 8
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Backwash at too high a rate is much less destructive than at too low a backwash rate
Frage 9
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Water with low turbidity is just as difficult to treat as those with increased turbidity.
Frage 10
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The detention time may be defined as the actual time that a small amount of water is retained in the sedimentation basin.
Frage 11
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Chlorine gas is extremely toxic and corrosive in moist atmospheres.
Frage 12
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In most types of filtration, particles are removed mainly by straining.
Frage 13
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Free available residual chlorine has the greatest disinfecting action of the chlorine compounds.
Frage 14
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A long, narrow rectangular sedimentation tank is the shape most likely to have short-circuiting problems.
Frage 15
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The Interim Enhanced Surface Water Treatment Rule does not address Cryptosporidium.
Frage 16
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The turbidity requirement under the Interim Enhanced Surface Water Treatment rule is < 0.3 NTU.
Frage 17
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150 lb. chlorine cylinders may be stored on their sides
Frage 18
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Ozone is highly reactive.
Frage 19
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When water temperatures increase, the flow through a sedimentation basin must be decreased.
Frage 20
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Too high a backwash rate may cause excessive loss of filter media.
Frage 21
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Chlorine gas is lighter than air.
Frage 22
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Alum Sludge is often returned to plant to "condition" raw water.
Frage 23
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Rapid Sand filters trap suspended matter in the biologically active Schmutzdecke.
Frage 24
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There is no minimum requirement for distribution chlorine residual under the SWTR.
Frage 25
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Floc gathers together during the flash-mixing process.
Frage 26
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If the chlorine demand has been met and there is still chlorine in the water, what is the remaining chlorine called?
Antworten
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Breakpoint
-
Residual
-
Dose
-
Demand
Frage 27
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Gas Chlorine is ______________________?
Frage 28
Frage
What is the difference between conventional and direct filtration?
Antworten
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No sedimentation
-
No coagulation
-
No Flocculation
-
No disinfection
Frage 29
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Turbidity is the expression of the _____________ of the water?
Antworten
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Alkalinity
-
pH of the water
-
Clarity
-
Water temperature
Frage 30
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Which of the following is more resistant to disinfection
Antworten
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Turbidity
-
Cysts
-
Coliform
-
All of the Above
Frage 31
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Water with a pH of 9 would be considered?
Antworten
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Acidic
-
Neutral
-
Ugly
-
Basic
Frage 32
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Currents within a settling basin could cause _____________.
Frage 33
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The main purpose of the jar test is to determine the best?
Frage 34
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Filtration technologies used to comply with Surface Water Treatment Rule include
Antworten
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Conventional
-
Slow Sand
-
Direct
-
All of the above
Frage 35
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Organic matter combined with chlorine can create?
Frage 36
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The coagulation process usually occurs within?
Antworten
-
30 seconds
-
5 minutes
-
15 minutes
-
30 minutes
Frage 37
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What is coagulation?
Antworten
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Clumping together of very fine particles into larger particles by the use of chemicals
-
Very small, finely divided solids that remain dispersed in a liquid for a long time
-
Gathering together of fine particles to form larger particles by a process of gentle mixing
-
Removal of particles through gravity
Frage 38
Frage
Field test method for chlorine is conducted using _________ method
Antworten
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Electrometric
-
Spans
-
DPD
-
OPR
Frage 39
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Which is not a characteristic of a rectangular sedimentation basin?
Frage 40
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Why should a minimum of two sedimentation basins be provided in all water treatment plants?
Antworten
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To allow for cleaning of a basin without requiring a plant shutdown
-
To minimize short-circuiting problems
-
To reduce the number of operators needed for O & M
-
Take advantage of common-wall technology
Frage 41
Frage
The Surface Water Treatment Rule requires ______ and ______ of Giardia
Antworten
-
Coagulation and sedimentation
-
Removal and inactivation
-
Disinfection and flocculation
-
Coagulation and disinfection
Frage 42
Frage
What is the purpose of the filtration process?
Antworten
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Cause very fine particles to clump together into larger particles
-
Kill disease-causing organisms
-
To remove particulate impurities and floc
-
Settle out larger suspended particles
Frage 43
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What is the purpose of the effluent zone in the sedimentation basin?
Antworten
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To provide smooth transition from the sedimentation basin to the settle water channel
-
To provide compression settling of the sludge
-
To reduce short-circuiting of water in the basin
-
To provide calm, undisturbed storage of flocculated water
Frage 44
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When added to water, chlorine will react with?
Antworten
-
Organic substances
-
Hardness
-
Inorganic substances
-
Both a and c
Frage 45
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On the chlorination breakpoint curve, between points 2 & 3 chlorine reacts with ammonia to form?
Antworten
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Monochloramine
-
Free chlorine
-
Dichloramine
-
Trichloramine
Frage 46
Frage
What is flocculation?
Antworten
-
Clumping together of very fine particles into larger particles by the use of chemicals
-
Gathering together of fine particles to form larger particles by the process of gentle mixing
-
Removal of iron and manganese
-
Very small, finely divided solids that remain dispersed in a liquid for a long time
Frage 47
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A disinfected water supply is one in which
Frage 48
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Which is not a form of Chlorine?
Antworten
-
Calcium Hypochlorite
-
Gas
-
Sodium Chloride
-
Sodium Hypochlorite
Frage 49
Frage
Why is ozone prepared onsite?
Antworten
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Because it acts quicker when produced at the application point
-
Because it is difficult to store in conventional containers
-
Because it is produced on demand
-
Because it is very unstable
Frage 50
Frage
Which is the correct order of filter materials in a multi-media or mixed media gravity filter (From top to Bottom)?
Antworten
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Coal, Garnet, Sand
-
Coal, Sand, Garnet
-
Garnet, Sand, Coal
-
Sand, Coal, Garnet
Frage 51
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Flash mixing includes
Antworten
-
Blinders
-
Surface currents
-
Baffled chambers
-
Barometric loops
Frage 52
Frage 53
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Most natural occurring particles in water are ____________
Antworten
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Positive charged
-
Have no charge
-
Negatively charged
-
Are bi-polar
Frage 54
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The disinfectant with the greatest disinfection potential is?
Antworten
-
Hypochlorous Acid (HOCI)
-
Monochloramine
-
Hydrochloric Acid (HCI)
-
Hypochlorite Ion (OCI)
Frage 55
Frage
The removal efficiency of a filter depends on the _____________
Frage 56
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In determining the purity of a water sample, it is usually tested for the presence of coliform bacteria because ___________.
Antworten
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It can be detected using a microscope
-
It can be done in the field
-
It is one of the disease-bearing bacteria
-
Its presence may indicate that the water has been contaminated
Frage 57
Frage
Most important filter effluent water quality change is?
Antworten
-
Chlorine demand
-
Nutrients
-
Turbidity
-
pH
Frage 58
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Factors affecting particle settling include
Antworten
-
Size
-
Density
-
Charge
-
All of the above
Frage 59
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How are particles removed by slow sand filtration?
Antworten
-
By chemical and physical disinfection
-
By straining, adsorption and biological action
-
By operation and maintenance procedures
-
By coagulation, flocculation and sedimentation
Frage 60
Frage
Good filter media characteristics include?
Antworten
-
Soft material
-
Highly soluble in water
-
Non-permeable
-
Inert
Frage 61
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Why is the turbidity of the water important when disinfecting water?
Antworten
-
Excessive turbidity will cause a significant shift in pH
-
Excessive turbidity will greatly reduce the efficiency of the disinfection chemical process
-
Excessive turbidity will cause a change in the hardness
-
Excessive turbidity will cause an adjustment
Frage 62
Frage
What could be the cause of floc size breaking up in flocculates?
Antworten
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Coagulent chemicals are inadequately mixed
-
Detention time too long
-
Mixing intensity is too high
-
Polymer dosage is too high
Frage 63
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Short circuiting in a sedimentation basin can be caused by
Antworten
-
Poor inlet baffling
-
Improper design
-
High inlet velocities
-
All of the above
Frage 64
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Which is not a zone in a sedimentation basin?
Antworten
-
Inlet zone
-
Sludge zone
-
Aeration zone
-
Settling zone
Frage 65
Frage
Destruction of harmful bacteria by chlorine is directly related to
Antworten
-
Contact time and chlorine concentration
-
Efficient chlorine dosage levels
-
Whether or not breakpoint chlorination is practiced
-
Whether perchlorination is practiced
Frage 66
Frage
Which is not an important factor when evaluating jar test results?
Antworten
-
Amount of floc formed
-
Alkalinity
-
Floc settling rate
-
Size of floc
Frage 67
Frage
Visual checks of the sedimentation basin include?
Antworten
-
Floc settling characteristics
-
Clarity of laundered water
-
Distribution of floc at basin inlet
-
All of the above
Frage 68
Frage
The surface water treatment rule requires which removal rate for Giardia?
Frage 69
Frage
The Interim Enhanced Surface Water Treatment Rule requires the maintenance of a minimum distribution chlorine residual of?
Antworten
-
0.2 mg/L
-
1.0 mg/L
-
2.0 mg/L
-
0.5 mg/L
Frage 70
Frage
Weak floc _____________?
Antworten
-
Does not adhere to filter media
-
Can be carried deep into filter
-
Causes increased turbidity of filtered water
-
All of the above
Frage 71
Frage
What operation changes in the sedimentation process should be considered by operators when colder water temperatures develop?
Antworten
-
Faster sludge removal rates must be Implemented
-
Surface skimming rates must be increased
-
Chemical dosages must be adjusted
-
None of the above
Frage 72
Frage
For conventional filtration plant under the IESWTR, the allowable filter effluent turbidity measured in 95% of the samples collected in a month is ___________ NTU?
Frage 73
Frage
What is a limitation of using ultraviolet rays for disinfection?
Antworten
-
The disruption of selective organic components of the cell
-
The removal of destroyed pathogenic microorganisms
-
The lack of a measurable residual
-
The selection of the optimum wave length
Frage 74
Frage
The "Total Coliform Rule" of the SDWA regulations requires the result of coliform testing to be given as?
Frage 75
Frage
What is the maximum feed rate in pounds per day from a 150lb. chlorine cylinder?
Antworten
-
10 lbs.
-
20 lbs.
-
40 lbs.
-
80 lbs.
Frage 76
Frage
The inactivation of pathogenic organisms is called?
Antworten
-
Sterilization
-
Oxidation
-
Pasteurization
-
Disinfection
Frage 77
Frage
The use of gas chlorine tends to _____________ the pH
Antworten
-
Lower
-
No effect
-
Raise
-
Neutralize
Frage 78
Frage
Parameters which affect disinfection include
Antworten
-
Color
-
pH
-
Temperature
-
Both b and c
Frage 79
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Chlorine Dioxide is composed of ______________ and chlorine
Antworten
-
Ammonia
-
Oxygen
-
Hydrogen Dioxide
-
Sodium Chloride
Frage 80
Frage
Sodium Hypochlorite is the active ingredient in _______________
Antworten
-
Liquid chlorine
-
Powdered chlorine
-
Granular chlorine
-
Gas chlorine
Frage 81
Frage
The reaction zone in a solids contact clarifier is 15 feet in diameter and 8 feet high. What is the detention time in minutes if the flow is 5 million gallons per day?
Antworten
-
3 gallons per minute
-
3472 gallons per minute
-
3.04 minutes
-
10,562.2 gallons
-
5 minutes
Frage 82
Frage
A well has a flow of 2500 rpm and a chlorine residual of 2.0 mg/L is required. The demand is 0.5 mg/L. If calcium hypochlorite 65% available chlorine is used, how many lbs./day of hypochlorite is required?
Antworten
-
3.6 lbs/day
-
65 lbs/day
-
75 lbs/day
-
92 lbs/day
-
115 lbs/day
Frage 83
Frage
Calculate the filtration rate in gallons per minute, per square foot (GPM/ft2) for a filter with a length of 50 feet by 40 feet when the applied flow is 3 million gallons per day?
Antworten
-
10 GPM/ft2
-
3.5 GPM/ft2
-
2.0 GPM/ft2
-
2.5 GPM/ft2
-
1.0 GPM/ft2
Frage 84
Frage
Treatment plant has a flow of 900 GPM and an average turbidity of 10 ntu. A total of 180 lbs. of alum is used in 24 hours. What is the alum dosage in mg/L?
Antworten
-
0.6 mg/L
-
10 mg/L
-
17 mg/L
-
28 mg/L
-
138 mg/L