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