17071064
Descrição
Quiz por Dean Lampman, atualizado more than 1 year ago
|
Criado por Dean Lampman
mais de 5 anos atrás
|
|
Questão 1
Questão
What does it mean when a belt filter press is washing out?
Responda
-
Water is overrunning the sides of the belt
-
Sludge is squeezing out from between the belt
-
The unit is being cleaned
-
The effluent line is clogged
Questão 2
Questão
In the five-stage bardenpho process, what occurs after the microorganisms pass from the first anoxic zone into the first aeration basin?
Responda
-
WAS is pumped from the aeration basin back to the head of the plant
-
A percentage of the mixed liquor is returned to the first anoxic zone
-
All of the mixed liquor passes directly into the second anoxic zone
-
All of the mixed liquor passes directly into the secondary clarifier
Questão 3
Questão
What kind of problems arise in the clarifier when the sludge is overstabilized?
Responda
-
Sludge settles too slowly and is hard to keep in the clarifier
-
Sludge settles too quickly causing high effluent turbidity due to pin floc
-
Sludge settles too slowly and may turn septic in the return sludge system
Questão 4
Questão
First stage BOD is also known by what term?
Responda
-
Nitrogenous BOD
-
Carbonaceous BOD
-
Metabolic BOD
-
Oxidation
Questão 5
Questão
What term is used to describe the liquid that leaves a centrifugal thickener through the effluent line?
Responda
-
Concentrate
-
Elutriation
-
Centrate
-
Precipitate
Questão 6
Questão
Why are primary clarifiers not very effective for removing BOD?
Responda
-
Most BOD is soluble and cannot be removed by sedimentation
-
Most BOD is insoluble, but not heavy enough to settle
-
Primary clarifiers cannot handle high organic loads
-
None of these answers
Questão 7
Questão
When denitrification is occurring, the microorganisms use methanol as a carbon food source. Where do they obtain the oxygen necessary to metabolize the methanol when there is no free oxygen present?
Responda
-
The microorganisms do not need oxygen to metabolize
-
From the nitrate ion
-
From the ammonia-nitrogen
-
From the gaseous nitrogen
Questão 8
Questão
Which modification of the activated sludge process is best suited for nitrification?
Responda
-
Complete mix
-
Extended Aeration
-
Step Feed
-
Contact Stabilization
Questão 9
Questão
Microorganisms that are in an anaerobic environment are then transferred to a proper environment containing food and oxygen where they take in excess amounts of phosphorus. What is this intake of excess phosphorus called?
Responda
-
Endogenous respiration
-
Luxury uptake
-
Anaerobic respiration
-
Absorption
Questão 10
Questão
What is the term used for water that is contained within the cell mass of sludge?
Responda
-
Bound water
-
Hard water
-
Molecular Water
-
Free Water
Questão 11
Questão
Which of the following has an ammonia odor?
Responda
-
Mercaptans
-
Indole
-
Skatole
-
Hydrogen Sulfide
Questão 12
Questão
What can be said about belt speed in a gravity belt filter thickener?
Responda
-
A. As belt speeds increases, the belt area in contact with the influent sludge increases
-
B. As belt speed increases, the belt area in contact with the influent sludge decreases
-
C. Belt speed should be as slow as possible without washing out the belt
-
Both A and C
Questão 13
Questão
In what order are the basins arranged in the five-stage Bardenpho process?
Responda
-
Anaerobic, anoxic, aeration, anoxic, aeration
-
Anoxic, anaerobic, aeration, anoxic, aeration
-
Aeration, anoxic, anaerobic, aeration, anoxic
-
Aeration, anaerobic, anoxic, aeration, anoxic
Questão 14
Questão
What type of thickener would work best when treating primary sludge?
Responda
-
Centrifuge
-
Gravity
-
Flotation
-
All of the above
Questão 15
Questão
Where should screen be located?
Responda
-
As close as possible to where the waste is being produced
-
As far as possible from where the sludge is being produced
-
As close to the plant influent as possible
-
At the aerator influent
Questão 16
Questão
When calculating how much activated sludge is being wasted, what must always be accounted for?
Responda
-
Solids lost in effluent
-
Solids in influent
-
DO in Aerator
-
Solids lost in effluent and solids in influent
Questão 17
Questão
What effect would increasing the return sludge aeration time have on the SVI?
Responda
-
Decrease
-
Increase
-
No change
-
Increase then decrease
Questão 18
Questão
When chlorine is added to water containing ammonia, the ammonia reacts with the hypochlorous acid and forms:
Responda
-
Nitrogen gas
-
Alkalinity
-
Chloramines
-
Nitrates
Questão 19
Questão
If air input to the aerator has not been increased and there is a significant increase in DO residual, what does this indicate and which process control adjustment should be made?
Responda
-
Increased MLVSS/increase wasting and increase RAS
-
Toxic shock load/increase wasting and decrease RAS
-
Toxic shock load/increase wasting and increase RAS
-
Increased MLVSS/decrease wasting and decrease RAS
Questão 20
Questão
How deep should sludge be when using a sand drying bed?
Responda
-
6-12 inches
-
1-3 inches
-
12-18 inches
-
2-4 feet
Questão 21
Questão
When wastewater has a pH on the low side of 6.5, what property will the wastewater's solid particles have?
Responda
-
High settleability
-
Low settleability
-
Negative ionic charges
-
Positive ionic charges
Questão 22
Questão
What may be added to wastewater when nutrient levels are too low to support the microorganisms?
Responda
-
Nitrogen and phosphorus
-
Ammonia and phosphoric acid
-
Sodium acetate
-
All of these
Questão 23
Questão
If the pH of wastewater drops low enough to inhibit nitrification, what has occurred and what should be done to fix the problem?
Responda
-
Too much alkalinity / Recarbonate to achieve proper pH
-
Not enough alkalinity / Add lime to achieve proper pH
-
Low DO / Increase air rate
-
High DO / Decrease air rate
Questão 24
Questão
At what DO would sulfate be reduced to sulfide?
Responda
-
0 mg/L
-
1.0 mg/l
-
2.0 mg/l
-
>2.0 mg/l
Questão 25
Questão
While operating a vacuum filter, the operator finds that the sludge cakes are too wet. What would be the best course of action?
Responda
-
Decrease vacuum
-
Decrease chemical conditioning
-
Decrease influent flow
-
Decrease drum speed
Questão 26
Questão
What conditions can cause forming?
Responda
-
High MCRT values
-
High MLSS
-
High concentration of filaments
-
All of these
Questão 27
Questão
The DO should be kept at _______ in the first anaerobic and anoxic zones when using the Bardenpho process?
Responda
-
2.0 mg/l
-
1.5 mg/l
-
0.5 mg/l
-
0 mg/l
Questão 28
Questão
When treating high organic loads, what process control adjustment should be made?
Responda
-
Decrease RAS
-
Increase RAS
-
Increase wasting
-
Decrease DO
Questão 29
Questão
What can cause belt blinding when operating a belt filter press?
Responda
-
Polymer undressing
-
Polymer overdosing
-
Loose belts
-
Belt speed too high
Questão 30
Questão
Why is the amount of food available to the microorganisms allowed to decrease during aerobic digestion?
Responda
-
To cause denitrification
-
To cause nitrification
-
To encourage endogenous respiration
-
To decrease turbidity
Questão 31
Questão
Why must special care be taken to avoid agitation of the wastewater during the denitrification process?
Responda
-
To avoid allowing free oxygen to enter the wastewater
-
To maintain aerobic conditions
-
To avoid disturbing the microorganisms
-
To decrease turbiditiy
Questão 32
Questão
Organisms that can only use molecular oxygen are called?
Responda
-
Anaerobes
-
Facultative
-
Obligate aerobes
-
Strict anaerobes
Questão 33
Questão
When is produced during nitrification that may reduce buffering capacity of the alkalinity and cause a subsequent lowering of the pH?
Responda
-
Hydrogen ions
-
Hydroxyl ions
-
Carbon dioxide
-
Acid
Questão 34
Questão
What term describes organisms that use inorganic materials for energy and growth?
Responda
-
Heterotrophic
-
Eutrophic
-
Autotrophic
-
Anaerobes
Questão 35
Questão
Emergency basins and storage tanks should be kept:
Responda
-
Full at all times
-
Filled half way
-
Empty or almost empty
-
Full during high flows
Questão 36
Questão
What may be indicated by a low respiration rate value?
Responda
-
Low F/M ration
-
High MLVSS
-
Short MCRT
-
Low F/M Ratio and High MLVSS
Questão 37
Questão
How much chlorine is required to oxidize 1 mg/L of ammonia-nitrogen to nitrogen gas?
Responda
-
4 mg/L
-
10 mg/L
-
12 mg/L
-
14 mg/L
Questão 38
Questão
Why does pH increase in most aeration systems?
Responda
-
Alkalinity is increased
-
Carbon dioxide is stripped from the wastewater
-
Microorganism activity increases
-
DO is increased
Questão 39
Questão
What chemical may be used to increase DO when mechanical aeration is insufficient?
Responda
-
Ammonia
-
Phosphorus
-
Nitrogen
-
Hydrogen peroxide
Questão 40
Questão
What kind of problems may arise in the clarifier when sludge is understabilized?
Responda
-
Sludge settles too slowly and is hard to keep in the clarifier
-
Sludge settles too quickly causing high effluent turbidity due to pin flocs
-
Sludge settles too slowly and may turn septic in the return sludge system
-
Sludge settles too slowly and is hard to keep in the clarifier and Sludge settles too slowly and may turn septic in the return sludge system
Questão 41
Questão
If a drop in pH occurs in an aerobic digester due to nitrification, what process control adjustment can be made to supress the growth of nitrifying bacteria?
Responda
-
Increase air rate and detention time
-
Decrease air rate and detention time
-
Decrease influent flow and increase detention time
-
Increase influent flow and air rate
Questão 42
Questão
If ammonia-nitrogen levels are too high, what process control adjustments can be made to correct this?
Responda
-
Decrease DO
-
Decrease MCRT
-
Increase DO
-
Increase WAS
Questão 43
Questão
For every milligram of ammonia - nitrogen converted to nitrate - nitrogen, how much alkalinity is consumed?
Responda
-
7.1 mg as CaCO3
-
4.5 mg as CaCO3
-
4.0 mg as CaCO3
-
2.5 mg as CaCO3
Questão 44
Questão
At which temperature would the generation of H2S form?
Responda
-
< 40° F
-
65° F
-
75° F
-
> 85° F
Questão 45
Questão
At which pH is all sulfide present only in the gaseous H2S form?
Responda
-
> 9
-
8.3
-
7.5
-
4.5
Questão 46
Questão
When sludge becomes too thick it may become resistant to pumping and cause:
Responda
-
Bound water
-
Coning
-
Bulking
-
Pin Floc
Questão 47
Questão
What chemicals can be used to condition sludge for dewatering?
Responda
-
Ferric chloride
-
Polymer
-
Lime
-
All of these
Questão 48
Questão
What is a selector?
Responda
-
A device used to divert wastewater to various tanks
-
A valve that regulates that flow of influent to the clarifier
-
A computerized system that automatically controls the distribution of influent
-
Compartments within a reactor that each favor the growth of certain organisms over others
Questão 49
Questão
What is the term for the process of removing odors by absorption?
Responda
-
Stripping
-
Scrubbing
-
Sponging
-
Scouring
Questão 50
Questão
How does thermal sludge conditioning aid in dewatering?
Responda
-
By precipitating the sludge
-
By release bound water
-
By destroying microorganisms
-
By floating the sludge
Questão 51
Questão
Where is the BEST point of application when breakpoint chlorination for nitrogen removal?
Responda
-
After the filters
-
Between the secondary clarifiers and filters
-
At the plant influent
-
In the aeration basin
Questão 52
Questão
What is one probable cause of low OUR values?
Responda
-
High F/M ratio
-
Low MCRT
-
Toxic shock load
-
Young sludge
Questão 53
Questão
What is the recommended level of DO for proper nitrification?
Responda
-
0.5 mg/L - 1.0 mg/L
-
1.0 mg/L - 1.5 mg/L
-
1.5 mg/L - 2.0 mg/L
-
2.0 mg/L - 4.0 mg/L
Questão 54
Questão
What is the best way to remove limestone buildup in pipes and pumps?
Responda
-
Acid
-
Hot water
-
Caustic soda
-
Alum
Questão 55
Questão
What is the typical DO range in pure oxygen system?
Responda
-
4-10 mg/L
-
1-5 mg/L
-
2-4 mg/L
-
1-10 mg/L
Questão 56
Questão
What is substrate
Responda
-
A chemical used by an organism to support its growth
-
The effluent from a centrifuge
-
A clear liquid left over after sludge is dewatered
-
A type of sludge residual
Questão 57
Questão
In the 5 stage Bardenpho process, what occurs in the first stage?
Responda
-
Microorganisms enter the aeration basin where they take in large amounts of phosphorus
-
Microorganisms enter the first anoxic zone where they begin denitrification
-
Microorganisms enter the anaerobic zone where they release their phosphorus
-
Microorganisms enter the first anoxic zone where they release their phosphorus
Questão 58
Questão
What happens when pressurized air saturated liquid is released at atmospheric pressure during flotation sludge thickening?
Responda
-
Sludge floats to the surface
-
Sludge settles
-
Denitrification
-
Nitrification
Questão 59
Questão
Which microorganisms may predominate when nitrogen and phosphorus levels are low?
Responda
-
Filamentous
-
Ciliates
-
Amoebas
-
Rotifers
Questão 60
Questão
Which microorganisms can cause bulking and foaming?
Responda
-
Filamentous
-
Rotifers
-
Ciliates
-
Protozoa
Questão 61
Questão
Polymers that have a positive charge are called?
Responda
-
Cationic
-
Anionic
-
Nonionic
-
Polyionic
Questão 62
Questão
What is the optimal pH when using alum to remove phosphorus?
Responda
-
6.0
-
8.0
-
10.0
-
11.0
Questão 63
Questão
The difference in pressure above and below the media of a gravity filter is called?
Responda
-
Head loss
-
Pressure differential
-
Flow rate
-
Concentration polarization
Questão 64
Questão
What term describes the condition where an oxygen deficient condition exists, but chemically bound oxygen such as nitrate is present?
Responda
-
Anaerobic
-
Aerobic
-
Anoxic
-
Endogenous
Questão 65
Questão
What is an indication of alum sulfate (Alum) overdosing?
Responda
-
Low pH
-
Cloudiness caused by high turbidity and suspended solids
-
High pH accompanied by pin floc
-
Low pH and cloudiness caused by high turbidity and suspended solids
Questão 66
Questão
Approximately how many pounds of oxygen are required to nitrify one pound of ammonia-nitrogen?
Responda
-
2.5 lbs
-
3.7 lbs
-
4.6 lbs
-
5.0 lbs
Questão 67
Questão
What is the proper term for the substance that may form in digested sludge lines and on the rotating components of centrifuges?
Responda
-
Centrate
-
Concentrate
-
Struvite
-
Precipitate
Questão 68
Questão
How deep should the sludge blanket be in gravity thickener?
Responda
-
1-3 ft
-
2-5 ft
-
3-4 ft
-
5-8 ft
Questão 69
Questão
Which microorganisms prefer lower pH levels around 6.0?
Responda
-
Phosphorus removal microorganisms
-
Volatile fatty acid removal microorganisms
-
Nitrifiers
-
Phosphorus removal microorganisms and nitrifiers
Questão 70
Questão
What is the lowest concentration of hydrogen sulfide that can be detected by the human nose?
Responda
-
1.0 ppb
-
0.5 ppb
-
1.5 ppb
-
2.0 ppb
Questão 71
Questão
High respiration rate values may indication?
Responda
-
Understabilzed organic matter
-
Overstabilzed organic matter
-
Low MLVSS
-
Low F/M ration
Questão 72
Questão
Which of the following is biodegradable and easily treated?
Responda
-
Emulsified oils & greases of vegetables and animal origin
-
Oils & greases of mineral origin
-
Heavy metals
-
H2S
Questão 73
Questão
Which of the following may be caused by excessive wasting?
Responda
-
High MLVSS
-
High MCRT
-
Low F/M ratio
-
High F/M ratio
Questão 74
Questão
Where is the best place to add chlorine when using it to control odors?
Responda
-
In the collection system ahead of the plant
-
In the primary clarifier
-
In the aerator
-
In the plant effluent
Questão 75
Questão
What process control adjustment should be made when there are a large number of amoeboids and flagellates present?
Responda
-
Increase wasting
-
Decrease wasting
-
Increase MCRT
-
Decrease DO
Questão 76
Questão
Organisms that can only use bound sources of oxygen are known by what term?
Responda
-
Obligate aerobes
-
Facultative
-
Anaerobic
Questão 77
Questão
Wasting is done from the RAS and the volatile content in the aerator changes. If the volatile content of the RAS is increasing, what adjustment should be made to the WAS flow rate?
Responda
-
No change
-
Increase
-
Decrease
-
Stop all wasting
Questão 78
Questão
What is the order in which microorganisms break down compounds containing oxygen?
Responda
-
Carbon dioxide, molecular oxygen, nitrate, sulfate, oxidized organics
-
Molecular oxygen, oxidized organics, carbon dioxide, nitrate, sulfate
-
Molecular oxygen, nitrate, sulfate, oxidized organics, carbon dioxide
-
Nitrate, molecular oxygen, sulfate, oxidized organics, carbon dioxide
Questão 79
Questão
Wasting is done from the RAS, and the volatile content in the aerator remains constant. If the volatile content of the RAS is decreasing, what should be done to the WAS flow rate?
Responda
-
No change
-
Increase
-
Decrease
-
Stop all wasting
Questão 80
Questão
Which is an organic gas that has an offensive skunk-like odor?
Responda
-
Mercaptans
-
Indole
-
Skatole
-
H2S
Questão 81
Questão
When is the best time to measure the sludge blanket depth in a clarifier?
Responda
-
During minimal flows
-
During maximum flows
-
At night when it's cool
-
Any time
Questão 82
Questão
What is the minimum DO that must be present in order for obligate aerobes to function properly?
Responda
-
0.5 mg/L
-
1.0 mg/L
-
1.5 mg/L
-
2.0 mg/L
Questão 83
Questão
When using a belt filter press to dewater sludge, water is forced between the belts and:
Responda
-
Pumped to the effluent line
-
Pumped with the RAS
-
Collected in filtrate trays
-
Allowed to evaporate
Questão 84
Questão
What are some of the properties of alum?
Responda
-
It reduces alkalinity and supports bacterial growth
-
It is very acidic
-
It increases alkalinity and pH
-
It reduces alkalinity and supports bacterial growth and it is very acidic
Questão 85
Questão
If the nitrate level in the effluent of the first anoxic basin during the 4 stage Bardenpho process is too high, what process control adjustment should be made?
Responda
-
Increase influent flow rate
-
Increase recycle rate
-
Increase air rate
-
Decrease recycle rate
Questão 86
Questão
What type of microorganism accomplishes denitrification by converting nitrate to nitrogen gas?
Responda
-
Autotrophic
-
Heterotropic
-
Eutropic
-
Thermotropic
Questão 87
Questão
Why do pH levels drop during nitrification
Responda
-
Acid formers predominate
-
Nitrate is acidic in nature
-
Alkalinity is destroyed
-
High sludge age
Questão 88
Questão
Why must pH of water be raised to between 10.8 and 11.5 during ammonia stripping?
Responda
-
To reduce microorganism population
-
So that all of the ammonia ion is converted to ammonia gas
-
To strengthen the buffering capacity
-
For odor control
Questão 89
Questão
When using odor removal towers to control odors, the pH of the wastewater being treated should not drop below:
Responda
-
10.0
-
8.0
-
7.0
-
6.0
Questão 90
Questão
What is the desired water column pressure in pure oxygen system?
Responda
-
4"-6"
-
2"-8"
-
3"-10"
-
1"-4"
Questão 91
Questão
What may be indicated by a high residual DO and low oxygen uptake rate in an anaerobic digester?
Responda
-
Toxic substances are present
-
Low pH
-
Low detention times
-
Toxic substances are present, Low pH, and Low detention times
Questão 92
Questão
How can lime be recovered for reuse?
Responda
-
Gravity belt press
-
Flocculation
-
Centrifuges
-
Floatation
Questão 93
Questão
What are nitrosomonas and nitrobacter?
Responda
-
Heterotophs that metabolize organic substances such as nitrate
-
Microorganisms that predominate in young sludge
-
Autotrophs that metabolize inorganic substances such as carbon dioxide and bicarbonate alkalinty
-
Two forms of nitrogen
Questão 94
Questão
What may be indicated by a high chlorine demand in the plant effluent when the plant requires nitrification?
Responda
-
Elevated nitrate levels
-
An imbalance of nitrobacter and nitrosomonas polulations
-
High pH levels
-
Elevated nitrate levels and an imbalance of nitrobacter and nitrosomonas polulations
Questão 95
Questão
When using the MCRT to determine process control adjustments, how long should you wait before making further changes if the desired MCRT is seven days?
Responda
-
3 days
-
10 days
-
2 to 3 weeks
-
4 to 6 weeks
Questão 96
Questão
What should an operator do when a high organic waste load enters the plant?
Responda
-
Decrease RAS flows and air input
-
Decrease WAS flow and air input
-
Increase RAS flow and air input
-
Increase WAS flow and air input
Questão 97
Questão
At what pH will carbon dioxide be stripped from water?
Responda
-
8.0
-
9.0
-
10.0
-
11.0
Questão 98
Questão
What is the recommended ratio of BOD: Nitrogen:Phosphorus (B:N:P) required for a treatment process?
Responda
-
100:5:1
-
100:50:10
-
10:5:1
-
100:20:10
Questão 99
Questão
What process control adjustments should be made when greater nitrification is required?
Responda
-
Increase MCRT
-
Decrease sludge age
-
Decrease pH
-
Decrease MCRT
Questão 100
Questão
When removing odors using the electrolytic process, electrons convert the salt in the brine to:
Responda
-
Chlorine
-
Calcium carbonate
-
Sodium hypochlorite
-
Calcium hypochlorite
Questão 101
Questão
How deep should the sludge blanket be in the clarifier when using the activated sludge process?
Responda
-
0.5 - 1 ft
-
3 - 5 ft
-
1 -3 ft
-
> 5 ft
Questão 102
Questão
Which modification of the activated sludge process uses two aeration tanks in which one of the tanks is used for seperate reaeration of the return sludge?
Responda
-
Extended aeration
-
Step feed aeration
-
Contact stabilization
-
Pure oxygen aeration
Questão 103
Questão
The use of metal salts for optimum enhanced chemical phosphorus removal is highly dependent on pH. Therefore, where is the optimum point for application of metal salts?
Responda
-
After denitrification when alkalinity levels are highest
-
Before denitrification because of the gain in alkalinity that occurs during anoxic reduction of nitrate-nitrogen
-
After nitrification because of the alkalinity depletion during the nitrification process
-
Before denitrification because of the gain in alkalinity that occurs during anoxic reduction of nitrate-nitrogen and after nitrification because of the alkalinity depletion during the nitrification process
Questão 104
Questão
For every pound of organic matter used by bacteria cells, approximately how many pounds of new bacteria cells are produced?
Responda
-
2.5 lbs
-
1.5 lbs
-
0.5 lbs
-
> 2.5 lbs
Questão 105
Questão
What is a common problem associated with ammonia stripping?
Responda
-
Scale buildup on pipes and pumps
-
Strong odors
-
Increased pH
-
Microorganisms are destroyed
Questão 106
Questão
What condition must exist for proper nitrification?
Responda
-
Low BOD
-
Available oxygen
-
A detention time of at least 4 hours
-
Low BOD, Available oxygen, and A detention time of at least 4 hours
Questão 107
Questão
What percent of oxygen is present in air?
Responda
-
20.9%
-
22%
-
23.5%
-
19.6%
Questão 108
Questão
Odors can be controlled by ________ the pH
Responda
-
Raising then lowering
-
Lowering
-
Lowering then raising
-
Raising
Questão 109
Questão
What process control adjustment can be made to minimize denitrification in a clarifier?
Responda
-
Decrease RAS
-
Decrease WAS
-
Increase RAS
-
Increase DO
Questão 110
Questão
Why is the COD test not recommended for wastewater's containing high salt concentrations?
Responda
-
Algae may interfere with the test
-
Brine contains high organic levels
-
Chloride may interfere with the chemical reactions
-
Salt has no effect on COD tests
Questão 111
Questão
If cake solids that are produced by a gravity belt thickener are too wet, what adjustments should be made?
Responda
-
Decrease belt speed and or increase belt tension
-
Increase belt speed and or decrease belt tension
-
Increase belt speed and or increase belt tension
-
Decrease belt speed and or decrease belt tension
Questão 112
Questão
For every pound of ammonia-nitrogen that is oxidized during nitrification, how many pounds of alkalinity are destroyed?
Responda
-
4.6 lbs
-
7.2 lbs
-
8.3 lbs
-
10.0 lbs
Questão 113
Questão
Why must sludge be removed from a gravity thickener at a faster rate during warmer temperatures?
Responda
-
To prevent denitrification
-
To prevent sludge from rising
-
To prevent incomplete nitrification
-
To prevent denitrification and to prevent sludge from rising
Questão 114
Questão
Which of the following is the easiest to dewater?
Responda
-
Primary sludge
-
Secondary sludge
-
Digester sludge
-
Waste activated sludge
Questão 115
Questão
After microorganisms take in and store large amounts of phosphorus they are transferred to an anaerobic environment. What effect does this have on microorganisms?
Responda
-
They settle to the bottom of the tank and are removed
-
They release their stored phosphorus
-
They immediately die and are wasted
-
They continue to absorb phosphorus
Questão 116
Questão
The first 75% of phosphorus precipitation occurs before the pH drops below?
Responda
-
10.0
-
8.0
-
7.0
-
6.0
Questão 117
Questão
What term is used to describe the clogging of the filter medium in a microscreen or vacuum filter?
Responda
-
Polarization
-
Blinding
-
Plugging
-
Breakthrough
Questão 118
Questão
What instrument is used to measure the amount of water draining through soil?
Responda
-
Rotameter
-
Venturi
-
Lysimeter
-
Winkler probe
Questão 119
Questão
What is the methanol to nitrogen ratio that should be maintained when denitrification is required?
Responda
-
1:2
-
2:1
-
3:1
-
5:1
Questão 120
Questão
If an anaerobic selector is being used to achieve phosphorus removal and the the next priority is denitrification, what would be the next selector necessary to achieve this?
Responda
-
Aerobic
-
Anoxic
-
Same selector (Anaerobic)
-
Any of the above
Questão 121
Questão
For optimal phosphorus removal, pH should not drop below?
Responda
-
4.0
-
6.0
-
8.0
-
11.0
Questão 122
Questão
What condition must exist for ammonium to be converted to gaseous ammonia so it can be removed by ammonia stripping?
Responda
-
pH must be raised to the 10.5-11.5 range
-
pH must be lowered to 6.0
-
DO must be increased
-
Nitrobacter must be present
Questão 123
Questão
What is the term used to describe the boundary layer between two substances?
Responda
-
Concentrate
-
Interface
-
Substrate
-
Coning
Questão 124
Questão
What adverse effect can high levels of ammonia have on receiving waters?
Responda
-
Oxygen depletion
-
Increase DO
-
Algal blooms
-
Oxygen depletion and algal blooms
Questão 125
Questão
Which is an example of suspended growth denitrifaction?
Responda
-
Rotating biological contractor
-
Trickling filter
-
Extended aeration
-
None of the above
Questão 126
Questão
When operating an Advanced Treatment facility using chemical treatment for solids removal, you discover high flows entering the system. You should?
Responda
-
Inspect the chemical feeders to determine if the chemicals being added do NOT cause a great increase/decrease in pH
-
Plan on reducing the sludge removal system from the clarifier
-
Prepare to feed a greater quantity of chemicals
-
Watch for chemical overdoses that could produce toxic conditions in the biological
Questão 127
Questão
When using polymer in a gravity thickening process for sludge, when would more polymer dosages be required? When the:
Responda
-
Hydraulic loading rate increases
-
Hydraulic loading to the unit decreases
-
Sludge selector speed is decreased
-
Solids loading to the unit decreases
Questão 128
Questão
When bacteria laden with phosphorous are faced with apparent death, they:
Responda
-
Absorb phosphorous from wastewater in large quantities
-
Absorb phosphorous from wastewater slowly
-
Begin to reproduce to save the species
-
Release phosphorous from their cell structure in large quantities
Questão 129
Questão
Head loss in a gravity filter is determined by?
Responda
-
Eff. turbidity minus Inf. Turbidity
-
Flow minus the weir overflow rate
-
Inf. Turbidity minus Eff. Turbidity
-
Measuring the water pressure above and below the filter media
Questão 130
Questão
What dosage of chlorine can be fatal in just a few breaths?
Responda
-
50 ppm
-
100 ppm
-
250 ppm
-
1000 ppm
Questão 131
Questão
What statement best describes at which speed a belt filter press should be operated?
Responda
-
The area of the belt determines the speed
-
The ideal belt speed is the slowest the operator can maintain without washing out the belt
-
The concentration of the sludge eff. determines the speed
-
The material of which the belt is made determines the speed
Questão 132
Questão
What steps should the operator take if "washing out" occurs while operating a belt filter press?
Responda
-
Decrease tension on belt
-
Decrease wash water rate
-
Increase sludge rate and belt speed
-
Lower flow rate and increase belt speed
Questão 133
Questão
A problem with plastic pipe laterals resting on the surface in a spray irrigation system is?
Responda
-
The pipe can deteriorate due to exposure to sunlight
-
Snakes and other lethal animals can lurk under the pipe
-
The pipe will whip violently during system operation
-
Distribution of the effluent will not be as effective
Questão 134
Questão
FDEP approved continuous on-line analyzing of reclaimed water effluent includes analyzing for:
Responda
-
CBOD5
-
pH, chlorine, and turbidity
-
D.O. and temperature
-
Fecal Coliform and Total Coliform
Questão 135
Questão
Lime is used more frequently for phosphorous removal than Aluminum Sulfate because Aluminum Sulfate:
Responda
-
Does not settle as rapidly in clarifiers
-
Is more expensive than lime
-
Raises the pH too much
-
Requires anaerobic conditions and lime does not
Questão 136
Questão
What process control adjustment should be made when a 30 minute settleometer test shows fast solids settling leaving pin-point floc? Increase the:
Responda
-
Aeration rate
-
MLSS
-
RAS rate
-
WAS rate
Questão 137
Questão
According to Chapter 62-600, FAC, Domestic Wastewater facilities, the basic disinfection requirement (using chlorine) is a :
Responda
-
0.5 mg/L total chlorine residual after 15 minutes contact time at average daily flow
-
0.5 mg/L minimum total chlorine after 15 minutes contact time at peak hourly flow
-
0.5 mg/L minimum total chlorine residual after 30 minutes contact time at maximum daily flow
-
1.0 mg/L total chlorine residual after 15 minutes contact time at maximum daily flow
Questão 138
Questão
In an aerobic digester, excessive air rates can contribute to?
Responda
-
An increase in the activity of biomass
-
Foaming problems
-
High solids carry over
-
Reduction of the activity of biomass
Questão 139
Questão
A common operational problem that can occur with ammonia stripping towers involves:
Responda
-
Asphyxiation if personnel remain in the tower too long
-
Corrosion due to the chemical reaction forming acids
-
Reduction of capacity due to media breakdown
-
Scale formation due to calcium carbonate build-up
Questão 140
Questão
What causes a loss of vacuum in a vacuum filter?
Responda
-
Change in effluent characteristics
-
Drum speed too low
-
Filter media misalignment or tear
-
Insufficient conditioning
Questão 141
Questão
According to Chapter 62-620, FAC, Wastewater Facility Permitting, the permittee shall retain treatment facility operating records for how many calendar years?
Responda
-
2 years
-
3 years
-
10 years
-
15 years
Questão 142
Questão
In lakes and deeper rivers, cold waters tend to slip below warmer waters because?
Responda
-
Warmer waters always rise to the top due to atmospheric pressure
-
Thermo clines force them to
-
Cold water is heavier or has a greater density
-
Caused by wind action at the surface
Questão 143
Questão
According to Chapter 62-602, FAC, Drinking water and Domestic wastewater treatment plant operators. The operator must report to the department any serious plant breakdown or condition causing or likely to cause any discharge not in compliance with the treatment plant permit within how many hours of the occurrence?
Responda
-
6 hours
-
12 hours
-
24 hours
-
48 hours
Questão 144
Questão
The plant EFF coliform count has failed to meet the required standards for disinfection. The supply of disinfectant is not the problem. There is adequate chlorine residual. To confirm the cause, it is most relevant to check the:
Responda
-
Chlorine in the stream mixing zone
-
Chlorine Contact Chamber for short circuiting
-
Chlorine Contact Chamber for solids scouring
-
Total chlorine residual analysis
Questão 145
Questão
How is the Fecal Coliform parameter evaluated?
Responda
-
The concentration is estimated by using the (MLN) Likely number method
-
The concentration is estimated by the TBEL method
-
The concentration is estimated by using the most probable number (MPN) method or the membrane filter (MF) method
-
The value is determined by microscopic examination
Questão 146
Questão
When reading the level of a column of liquid in a graduated cylinder, burette or manometer, you should?
Responda
-
Fill the glassware to 10 centimeters below the lip of the glassware and record
-
Hold a solid color sheet of paper behind the glassware and record the level to the nearest 10 millimeters
-
Record the level of the bottom of the meniscus of the liquid being measured
-
View the liquid level from an elevation equal to the liquid level and read the top of two liquid level lines
Questão 147
Questão
According to Chapter 62-601, FAC, Domestic W/W treatment plant monitoring, after July 1, 1993, the tests for on-site parameters pH and chlorine residual shall be performed by or under the direction of ?
Responda
-
A certified laboratory or a certified operator
-
Plant laborers
-
Plant Technicians
-
The permittee
Questão 148
Questão
What should be the pH in a rapid-mix basin for a maximum phosphorous removal efficiency when using lime?
Responda
-
5.0
-
6.0
-
8.3
-
11.0
Questão 149
Questão
Secondary clarifiers are showing straggler floc lost over weirs. Microscopic exam shows few free swimmers, majority of flagellates. SVI is increasing. What visual observation and test results would you expect?
Responda
-
Dark foam, increasing F/M and SRT, decreasing turbidity
-
Light brown foam, decreasing F/M and SRT, decreasing turbidity
-
Light brown to white foam, increasing F/M, dalling SRT and increasing turbidity
-
White foam, decreasing F/M, falling SRT, increased turbidity
Questão 150
Questão
The plant EFF coliform count has failed to meet the required standards for disinfection. The supply of disinfectant is not the problem. There is adequate chlorine residual. The best solution is to?
Responda
-
Chlorinate to breakpoint
-
Decrease the flow to the steam mixing zone
-
Increase the chlorinator capacity
-
Install additional baffling
Questão 151
Questão
Which statement is correct concerning confined spaces?
Responda
-
Confined spaces are defined as those that concurrently provide difficult access and/or exit combined with inadequate or deficient ventilation.
-
Monitoring the atmosphere within a confined space is required each hour and is logged into the confined space log book
-
You may enter a confined space only when oxygen levels are above 20%
-
You may process in a confined space only if air contamination exists
Questão 152
Questão
If a sand drying bed has a problem with the media becoming clogged, what should the operator do first?
Responda
-
Have the contractor replace all the media but leave the gravel intact
-
Investigate the type of sand being used and recommend a different type
-
Rake the surface of the bed, removing the upper 2 to 3 inches of sand, and replace the sand with fresh sand
-
Remove the sand, wash it, check the under-drain, then replace the sand
Questão 153
Questão
What should be the pH in a rapid-mix basin for maximum phosphorous removal efficiency when using lime?
Responda
-
5.0
-
6.0
-
8.3
-
11.0
Questão 154
Questão
What is the most common method of EFF disposal?
Responda
-
Evaporation/Percolation ponds1
-
In deep wells
-
In receiving waters
-
Land disposal
Questão 155
Questão
What would be the usual approach to measure the impact of a discharge to receiving waters?
Responda
-
Analyze the plants performance evaluations
-
Compare the in-plant measurements measurements to down stream receiving waters
-
Review the Grab sample measurements
-
Take a measurement in the upstream, unaffected area, and compare to a down stream affected area
Questão 156
Questão
What does not represent a potential hazard of working in a wastewater treatment laboratory?
Responda
-
Burns
-
Electrical shock
-
Hypothermia
-
Infectious materials
Questão 157
Questão
An instrument used in a laboratory that measures the intensity of color or particular wavelength is a ?
Responda
-
Color standard
-
Nephelometer
-
Spectrophotometer
-
Turbidimeter
Questão 158
Questão
A gravity filter experiences rapid build-up of head loss. What could be a probable cause?
Responda
-
Applied water flow rate too low
-
Incomplete backwash cycle
-
Media breakthrough
-
Turbidimeter
Questão 159
Questão
What problems may develop during the injection of reclaimed wastewater into deep wells?
Responda
-
Contamination of groundwater
-
Lowering of groundwater table
-
Saltwater intrusion
-
Severe hydraulic overload
Questão 160
Questão
According to state regulations, a wastewater plant shall maintain a pH in the effluent after disinfection within what range?
Responda
-
2.5 - 4.5
-
4.5 - 6.0
-
6.0 - 8.5
-
8.5 - 10.5
Questão 161
Questão
In chapter 62-699, FAC, Treatment Plant Classification and Staffing, wastewater treatment plants are classified in order to prescribe the lowest class of certified operators who will be permitted to operate the treatment plant. This classification system is based on what (2) factors?
Responda
-
Design flow and treatment type
-
Flow and treatment efficiency
-
Population and flow
-
Population served and treatment type
Questão 162
Questão
Two inorganic gases giving off the most offensive odors and which is a main concern of operators when controlling odors are?
Responda
-
Ammonia and skatole
-
Hydrogen sulfide and ammonia
-
Mercaptans and indole
-
Methane and ammonia
Questão 163
Questão
The recovery of a stuck anaerobic digester can be accelerated be neutralizing the acids with a caustic material like?
Responda
-
Aluminum sulfate
-
Calcium hypochlorite
-
Lime
-
Sodium hypochlorite
Questão 164
Questão
When operating an advanced treatment facility using chemical treatment for solids removal, you discover high flows entering the system. The first step you should take is to?
Responda
-
Inspect the chemical feeder for proper output
-
Prepare jar tests to determine dosage that will be good for increased detention
-
Prepare jar tests to determine dosage that will be good for decreased detention time
-
Run influent turbidity tests hourly to see if the turbidity is actually increasing
Questão 165
Questão
Even though a process control test is accurately performed, which one of the following could result in meaningless findings?
Responda
-
The ambient temperature being several degrees cooler than normal
-
The analyst not being certified
-
The sample not being representative of the process stream being sampled
-
The use of class A glassware instead class B glassware
Questão 166
Questão
It takes about 22% less O2 to process 1 lb of carbonaceous waste than 1 lb of nitrogenous waste. What does this indicate?
Responda
-
Additional DO is required to nitrify
-
Carbonaceous material should be add to the MLVSS
-
Carbonaceous wastes take longer to digest
-
Nitrogenous wastes are easily oxidized
Questão 167
Questão
To determine the location and amount of lowest dissolved oxygen downstream from a wastewater effluent discharge, it is necessary to?
Responda
-
Conduct an annual measurment survey
-
Conduct an oxygen profile of the stream
-
Conduct an oxygen profile of the treatment plant
-
Observe the aquatic life
Questão 168
Questão
A sand and gravel filter had been working well, but eventually head loss occurred. Performance did not improve significantly following backwashing. What is the most probable cause?
Responda
-
The backwash water overloaded the system
-
The backwash time was too short
-
The backwash time was too long
-
There was excessive auxiliary scour
Questão 169
Questão
The floating cover on a primary anaerobic digester appears to be tilting. Inspection of the rollers indicates that they are not the problem. Probing the annular space results in finding a thick scum accumulation. What should be done at this point?
Responda
-
Attach a crane cable to one side and lift the corner
-
Decrease the mixing so the scum will be broken up
-
Use chemicals or degreasing agents, then hose down the scum bucket through the inspection ports
-
Immediately drain the tank before an explosion takes place
Questão 170
Questão
Nitrification in the activated sludge process?
Responda
-
Decreases alkalinity and increases pH
-
Decreases alkalinity and pH
-
Increases alkalinity and pH
-
Increases alkalinity and decreases pH
Questão 171
Questão
Which statement is most correct concerning dissolved oxygen content in water?
Responda
-
An increase in water temperature causes an increase in DO
-
Decreases in dissolved oxygen content in receiving water is immediately noticed
-
An increase in temperature causes a decrease in dissolved oxygen concentration
-
Temperature has no effect on dissolved oxygen concentrations
Questão 172
Questão
Rapid accumulation on the surface of a single media sand filter results in very rapid head loss. The solution is ?
Responda
-
Improve prior clarification
-
Increase chemical coagulation
-
Reduce filter backwash time
-
Reduce the filter air scrubbing time
Questão 173
Questão
In the microscopic exam of the mixed liquor, you observe a dominance of rotifers and nematodes. What would this be indicative of?
Responda
-
Bulking sludge that settles slowly leaving straggler floc
-
Old sludge that settles rapidly, leaving pin floc
-
Rising sludge that settles rapidly, leaving fluffy floc
-
Young sludge that settles slowly, leaving pin floc
Questão 174
Questão
When using break-point chlorination for ammonia removal, how many ppm of chlorine are needed to remove 1 ppm of ammonia?
Responda
-
1
-
5
-
8
-
10
Questão 175
Questão
Misalignment of a driver and a driven piece of equipment can cause?
Responda
-
Premature bearing failure
-
Excessive wear of the slip rings
-
The packing to leak
-
Valve chatter
Questão 176
Questão
Effluent quality has changed from excellent to poor. A microbial study indicates a decrease of stalked ciliates and rotifers. Now, the predominance is free swimming and flagellates. This observation indicates that the ?
Responda
-
MCRT is decreasing
-
MCRT is increasing
-
Process is moving toward a more stable condition
-
Treatment efficiency is increasing
Questão 177
Questão
In a suspended growth reactor used for Denitrification
Responda
-
A carbon food source is needed for proper metabolism of the organisms
-
A dissolved oxygen level of at least 2.0 mg/L should be maintained in the aeration tank at all times
-
Nitrate is first converted to ammonium, then to nitrite
-
Nitrite is first converted to nitrate then ammonium
Questão 178
Questão
The strategy of allowing chlorinated water to stand for 24 to 48 hrs in the rapid sand filter and thoroughly backwashing media is a remedy for?
Responda
-
Curing breakthroughs
-
Remove dissolved air which causes air binding
-
Removing grease and oil from the filter wells
-
Removing mud balls
Questão 179
Questão
When a 5 min observation of the settlability test indicates fast settling (e.g., 500 ml), what process change should be made?
Responda
-
Decrease the RAS
-
Increase the aeration and RAS
-
Increase the aeration
-
Increase the wasting rate
Questão 180
Questão
For ammonia stripping to be successful:
Responda
-
Nitrosmonas and Nitrobacters must be present
-
Chemicals must be added to convert nitrogen to nitrate
-
The pH must be raised to approximately 10.8 to 11.5
-
The wastewater to be treated must be stripped of its dissolved oxygen content first
Questão 181
Questão
Water quality criteria for wastewater reclaimed for public access includes:
Responda
-
Complete lack of BOD
-
High level disinfection
-
No dissolved inorganic solids
-
50 mg/L TSS
Questão 182
Questão
What is the optimum temperature range for the nitrification process?
Responda
-
70 ° and 100 ° F
-
60 ° and 90 ° F
-
65 ° and 85 ° F
-
10 ° and 20 ° F
Questão 183
Questão
CO2 is stripped at pH below ___ and retained at a pH above ___
Responda
-
7.0 and 10
-
6.0 and 11
-
8.3 and 9.5
-
8.3 and 8.3
Questão 184
Questão
How much lime is required per ton of primary sludge?
Responda
-
100-200 lbs / ton
-
80-90 lbs / ton
-
150-175 lbs / ton
-
175-250 lbs / ton
Questão 185
Questão
What happens to phosphorus in a plant effluent when mixed with lime?
Responda
-
Phosphorus, calcium and hydroxyl ion compounds are formed
-
Phosphorus carbonate precipitate is formed
-
Phosphorus will cause a reaction that lowers the pH
-
Phosphorus will form a soluble sludge
Questão 186
Questão
What is utilized as a carbon source?
Responda
-
Nitrogen
-
Phosphorus
-
Methanol
-
Aerobic bacteria
Questão 187
Questão
In a centrifuge series, centrate from the ____ centrifuge contains most of the phosphorus?
Responda
-
First
-
Second
-
Third
-
Last
Questão 188
Questão
Using ION exchange for nitrogen removal; what is the name of the resin used?
Responda
-
Clinoptilolite
-
Zemalite
-
Miller lite
-
Red line resin
Questão 189
Questão
Supplemental phosphorus can be provided by using what items?
Responda
-
Phosphoric acid
-
Ammonia
-
Phosphate fertilizer
-
Phosphoric acid and Phosphate fertilizer
Questão 190
Questão
Filters should be back washed at what type of flow?
Responda
-
Slow so the filter material stays put
-
Fast just keeping the filter media in the bay
-
Adequate to fluidize the media
-
Fast just letting a small amount of media material to be washed away
Questão 191
Questão
What types of carbon food sources may be used in denitrification fixed film reactor to promote biological metabolism?
Responda
-
Hydrogen sulfide, primary effluent, source of high carbon food
-
Nitrate, primary effluent, source of high carbon food
-
Magnesium, primary effluent, source of high carbon food
-
Methanol, primary effluent, source of high carbon food
Questão 192
Questão
What may be used as a phosphorous supplement?
Responda
-
Dissolved triple superphosphate, phosphate fertilizer, phosphoric acid
-
Aqueous ammonia, anhydrous ammonia
-
Seed sludge
-
Cationic Polymers
Questão 193
Questão
What may be used as a nitrogen supplement?
Responda
-
Dissolved triple superphosphate, phosphate fertilizer, phosphoric acid
-
Aqueous ammonia, anhydrous ammonia
-
Seed sludge
-
Cationic Polymers
Questão 194
Questão
Methanol is?
Responda
-
An alcohol compound which can be ingested in small amounts without harm
-
A common component of many alcoholic beverages
-
Composed of hydrogen, oxygen, carbon and nitrogen - CH3OH
-
A fuel additive and it is highly flammable
Questão 195
Questão
What do autotrophic nitrifiers use as a carbon source?
Responda
-
Bicarbonate alkalinity
-
Lime
-
Algae
-
Nitrobacter bacteria
Questão 196
Questão
When denitrification is occurring, the microorganisms use methanol as a carbon food source. Where do they obtain the oxygen necessary to metabolize the methanol when there is no free oxygen present?
Responda
-
The microorganisms do not need oxygen to metabolize methanol
-
From the nitrate ion
-
From the ammonia-nitrogen
-
From the gaseous nitrogen
Questão 197
Questão
What may be added to wastewater when the nutrient levels are too low to support the microorganism population?
Responda
-
Nitrogen and phosphorus
-
Ammonia and phosphoric acid
-
Sodium acetate
-
All of the above
Questão 198
Questão
When treating high organic loads, what process control adjustments should be made?
Responda
-
Decrease RAS
-
Increase RAS
-
Increase wasting
-
Decrease DO
Questão 199
Questão
The DO should be kept at ____ in the first anaerobic and anoxic zones when using the Bardenpho process?
Responda
-
2.0 mg/l
-
1.5 mg/l
-
0.5 mg/l
-
0 mg/l
Questão 200
Questão
Why is the amount of food available to the microorganisms allowed to decrease during aerobic digestion?
Responda
-
To cause denitrification
-
To cause nitrification
-
To encourage endogenous respiration
-
To decrease turbidity
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