What does it mean when a belt filter press is washing out?
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
In the five-stage bardenpho process, what occurs after the microorganisms pass from the first anoxic zone into the first aeration basin?
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
What kind of problems arise in the clarifier when the sludge is overstabilized?
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
First stage BOD is also known by what term?
Nitrogenous BOD
Carbonaceous BOD
Metabolic BOD
Oxidation
What term is used to describe the liquid that leaves a centrifugal thickener through the effluent line?
Concentrate
Elutriation
Centrate
Precipitate
Why are primary clarifiers not very effective for removing BOD?
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
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?
The microorganisms do not need oxygen to metabolize
From the nitrate ion
From the ammonia-nitrogen
From the gaseous nitrogen
Which modification of the activated sludge process is best suited for nitrification?
Complete mix
Extended Aeration
Step Feed
Contact Stabilization
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?
Endogenous respiration
Luxury uptake
Anaerobic respiration
Absorption
What is the term used for water that is contained within the cell mass of sludge?
Bound water
Hard water
Molecular Water
Free Water
Which of the following has an ammonia odor?
Mercaptans
Indole
Skatole
Hydrogen Sulfide
What can be said about belt speed in a gravity belt filter thickener?
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
In what order are the basins arranged in the five-stage Bardenpho process?
Anaerobic, anoxic, aeration, anoxic, aeration
Anoxic, anaerobic, aeration, anoxic, aeration
Aeration, anoxic, anaerobic, aeration, anoxic
Aeration, anaerobic, anoxic, aeration, anoxic
What type of thickener would work best when treating primary sludge?
Centrifuge
Gravity
Flotation
All of the above
Where should screen be located?
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
When calculating how much activated sludge is being wasted, what must always be accounted for?
Solids lost in effluent
Solids in influent
DO in Aerator
Solids lost in effluent and solids in influent
What effect would increasing the return sludge aeration time have on the SVI?
Decrease
Increase
No change
Increase then decrease
When chlorine is added to water containing ammonia, the ammonia reacts with the hypochlorous acid and forms:
Nitrogen gas
Alkalinity
Chloramines
Nitrates
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?
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
How deep should sludge be when using a sand drying bed?
6-12 inches
1-3 inches
12-18 inches
2-4 feet
When wastewater has a pH on the low side of 6.5, what property will the wastewater's solid particles have?
High settleability
Low settleability
Negative ionic charges
Positive ionic charges
What may be added to wastewater when nutrient levels are too low to support the microorganisms?
Nitrogen and phosphorus
Ammonia and phosphoric acid
Sodium acetate
All of these
If the pH of wastewater drops low enough to inhibit nitrification, what has occurred and what should be done to fix the problem?
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
At what DO would sulfate be reduced to sulfide?
0 mg/L
1.0 mg/l
2.0 mg/l
>2.0 mg/l
While operating a vacuum filter, the operator finds that the sludge cakes are too wet. What would be the best course of action?
Decrease vacuum
Decrease chemical conditioning
Decrease influent flow
Decrease drum speed
What conditions can cause forming?
High MCRT values
High MLSS
High concentration of filaments
The DO should be kept at _______ in the first anaerobic and anoxic zones when using the Bardenpho process?
1.5 mg/l
0.5 mg/l
0 mg/l
When treating high organic loads, what process control adjustment should be made?
Decrease RAS
Increase RAS
Increase wasting
Decrease DO
What can cause belt blinding when operating a belt filter press?
Polymer undressing
Polymer overdosing
Loose belts
Belt speed too high
Why is the amount of food available to the microorganisms allowed to decrease during aerobic digestion?
To cause denitrification
To cause nitrification
To encourage endogenous respiration
To decrease turbidity
Why must special care be taken to avoid agitation of the wastewater during the denitrification process?
To avoid allowing free oxygen to enter the wastewater
To maintain aerobic conditions
To avoid disturbing the microorganisms
To decrease turbiditiy
Organisms that can only use molecular oxygen are called?
Anaerobes
Facultative
Obligate aerobes
Strict anaerobes
When is produced during nitrification that may reduce buffering capacity of the alkalinity and cause a subsequent lowering of the pH?
Hydrogen ions
Hydroxyl ions
Carbon dioxide
Acid
What term describes organisms that use inorganic materials for energy and growth?
Heterotrophic
Eutrophic
Autotrophic
Emergency basins and storage tanks should be kept:
Full at all times
Filled half way
Empty or almost empty
Full during high flows
What may be indicated by a low respiration rate value?
Low F/M ration
High MLVSS
Short MCRT
Low F/M Ratio and High MLVSS
How much chlorine is required to oxidize 1 mg/L of ammonia-nitrogen to nitrogen gas?
4 mg/L
10 mg/L
12 mg/L
14 mg/L
Why does pH increase in most aeration systems?
Alkalinity is increased
Carbon dioxide is stripped from the wastewater
Microorganism activity increases
DO is increased
What chemical may be used to increase DO when mechanical aeration is insufficient?
Ammonia
Phosphorus
Nitrogen
Hydrogen peroxide
What kind of problems may arise in the clarifier when sludge is understabilized?
Sludge settles too quickly causing high effluent turbidity due to pin flocs
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
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?
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
If ammonia-nitrogen levels are too high, what process control adjustments can be made to correct this?
Decrease MCRT
Increase DO
Increase WAS
For every milligram of ammonia - nitrogen converted to nitrate - nitrogen, how much alkalinity is consumed?
7.1 mg as CaCO3
4.5 mg as CaCO3
4.0 mg as CaCO3
2.5 mg as CaCO3
At which temperature would the generation of H2S form?
< 40° F
65° F
75° F
> 85° F
At which pH is all sulfide present only in the gaseous H2S form?
> 9
8.3
7.5
4.5
When sludge becomes too thick it may become resistant to pumping and cause:
Coning
Bulking
Pin Floc
What chemicals can be used to condition sludge for dewatering?
Ferric chloride
Polymer
Lime
What is a selector?
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
What is the term for the process of removing odors by absorption?
Stripping
Scrubbing
Sponging
Scouring
How does thermal sludge conditioning aid in dewatering?
By precipitating the sludge
By release bound water
By destroying microorganisms
By floating the sludge
Where is the BEST point of application when breakpoint chlorination for nitrogen removal?
After the filters
Between the secondary clarifiers and filters
At the plant influent
In the aeration basin
What is one probable cause of low OUR values?
High F/M ratio
Low MCRT
Toxic shock load
Young sludge
What is the recommended level of DO for proper nitrification?
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
What is the best way to remove limestone buildup in pipes and pumps?
Hot water
Caustic soda
Alum
What is the typical DO range in pure oxygen system?
4-10 mg/L
1-5 mg/L
2-4 mg/L
1-10 mg/L
What is substrate
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
In the 5 stage Bardenpho process, what occurs in the first stage?
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
What happens when pressurized air saturated liquid is released at atmospheric pressure during flotation sludge thickening?
Sludge floats to the surface
Sludge settles
Denitrification
Nitrification
Which microorganisms may predominate when nitrogen and phosphorus levels are low?
Filamentous
Ciliates
Amoebas
Rotifers
Which microorganisms can cause bulking and foaming?
Protozoa
Polymers that have a positive charge are called?
Cationic
Anionic
Nonionic
Polyionic
What is the optimal pH when using alum to remove phosphorus?
6.0
8.0
10.0
11.0
The difference in pressure above and below the media of a gravity filter is called?
Head loss
Pressure differential
Flow rate
Concentration polarization
What term describes the condition where an oxygen deficient condition exists, but chemically bound oxygen such as nitrate is present?
Anaerobic
Aerobic
Anoxic
Endogenous
What is an indication of alum sulfate (Alum) overdosing?
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
Approximately how many pounds of oxygen are required to nitrify one pound of ammonia-nitrogen?
2.5 lbs
3.7 lbs
4.6 lbs
5.0 lbs
What is the proper term for the substance that may form in digested sludge lines and on the rotating components of centrifuges?
Struvite
How deep should the sludge blanket be in gravity thickener?
1-3 ft
2-5 ft
3-4 ft
5-8 ft
Which microorganisms prefer lower pH levels around 6.0?
Phosphorus removal microorganisms
Volatile fatty acid removal microorganisms
Nitrifiers
Phosphorus removal microorganisms and nitrifiers
What is the lowest concentration of hydrogen sulfide that can be detected by the human nose?
1.0 ppb
0.5 ppb
1.5 ppb
2.0 ppb
High respiration rate values may indication?
Understabilzed organic matter
Overstabilzed organic matter
Low MLVSS
Which of the following is biodegradable and easily treated?
Emulsified oils & greases of vegetables and animal origin
Oils & greases of mineral origin
Heavy metals
H2S
Which of the following may be caused by excessive wasting?
High MCRT
Low F/M ratio
Where is the best place to add chlorine when using it to control odors?
In the collection system ahead of the plant
In the primary clarifier
In the aerator
In the plant effluent
What process control adjustment should be made when there are a large number of amoeboids and flagellates present?
Decrease wasting
Increase MCRT
Organisms that can only use bound sources of oxygen are known by what term?
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?
Stop all wasting
What is the order in which microorganisms break down compounds containing oxygen?
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
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?
Which is an organic gas that has an offensive skunk-like odor?
When is the best time to measure the sludge blanket depth in a clarifier?
During minimal flows
During maximum flows
At night when it's cool
Any time
What is the minimum DO that must be present in order for obligate aerobes to function properly?
0.5 mg/L
1.0 mg/L
1.5 mg/L
2.0 mg/L
When using a belt filter press to dewater sludge, water is forced between the belts and:
Pumped to the effluent line
Pumped with the RAS
Collected in filtrate trays
Allowed to evaporate
What are some of the properties of alum?
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
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?
Increase influent flow rate
Increase recycle rate
Increase air rate
Decrease recycle rate
What type of microorganism accomplishes denitrification by converting nitrate to nitrogen gas?
Heterotropic
Eutropic
Thermotropic
Why do pH levels drop during nitrification
Acid formers predominate
Nitrate is acidic in nature
Alkalinity is destroyed
High sludge age
Why must pH of water be raised to between 10.8 and 11.5 during ammonia stripping?
To reduce microorganism population
So that all of the ammonia ion is converted to ammonia gas
To strengthen the buffering capacity
For odor control
When using odor removal towers to control odors, the pH of the wastewater being treated should not drop below:
7.0
What is the desired water column pressure in pure oxygen system?
4"-6"
2"-8"
3"-10"
1"-4"
What may be indicated by a high residual DO and low oxygen uptake rate in an anaerobic digester?
Toxic substances are present
Low detention times
Toxic substances are present, Low pH, and Low detention times
How can lime be recovered for reuse?
Gravity belt press
Flocculation
Centrifuges
Floatation
What are nitrosomonas and nitrobacter?
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
What may be indicated by a high chlorine demand in the plant effluent when the plant requires nitrification?
Elevated nitrate levels
An imbalance of nitrobacter and nitrosomonas polulations
High pH levels
Elevated nitrate levels and an imbalance of nitrobacter and nitrosomonas polulations
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?
3 days
10 days
2 to 3 weeks
4 to 6 weeks
What should an operator do when a high organic waste load enters the plant?
Decrease RAS flows and air input
Decrease WAS flow and air input
Increase RAS flow and air input
Increase WAS flow and air input
At what pH will carbon dioxide be stripped from water?
9.0
What is the recommended ratio of BOD: Nitrogen:Phosphorus (B:N:P) required for a treatment process?
100:5:1
100:50:10
10:5:1
100:20:10
What process control adjustments should be made when greater nitrification is required?
Decrease sludge age
Decrease pH
When removing odors using the electrolytic process, electrons convert the salt in the brine to:
Chlorine
Calcium carbonate
Sodium hypochlorite
Calcium hypochlorite
How deep should the sludge blanket be in the clarifier when using the activated sludge process?
0.5 - 1 ft
3 - 5 ft
1 -3 ft
> 5 ft
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?
Extended aeration
Step feed aeration
Contact stabilization
Pure oxygen aeration
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?
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
For every pound of organic matter used by bacteria cells, approximately how many pounds of new bacteria cells are produced?
1.5 lbs
0.5 lbs
> 2.5 lbs
What is a common problem associated with ammonia stripping?
Scale buildup on pipes and pumps
Strong odors
Increased pH
Microorganisms are destroyed
What condition must exist for proper nitrification?
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
What percent of oxygen is present in air?
20.9%
22%
23.5%
19.6%
Odors can be controlled by ________ the pH
Raising then lowering
Lowering
Lowering then raising
Raising
What process control adjustment can be made to minimize denitrification in a clarifier?
Decrease WAS
Why is the COD test not recommended for wastewater's containing high salt concentrations?
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
If cake solids that are produced by a gravity belt thickener are too wet, what adjustments should be made?
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
For every pound of ammonia-nitrogen that is oxidized during nitrification, how many pounds of alkalinity are destroyed?
7.2 lbs
8.3 lbs
10.0 lbs
Why must sludge be removed from a gravity thickener at a faster rate during warmer temperatures?
To prevent denitrification
To prevent sludge from rising
To prevent incomplete nitrification
To prevent denitrification and to prevent sludge from rising
Which of the following is the easiest to dewater?
Primary sludge
Secondary sludge
Digester sludge
Waste activated sludge
After microorganisms take in and store large amounts of phosphorus they are transferred to an anaerobic environment. What effect does this have on microorganisms?
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
The first 75% of phosphorus precipitation occurs before the pH drops below?
What term is used to describe the clogging of the filter medium in a microscreen or vacuum filter?
Polarization
Blinding
Plugging
Breakthrough
What instrument is used to measure the amount of water draining through soil?
Rotameter
Venturi
Lysimeter
Winkler probe
What is the methanol to nitrogen ratio that should be maintained when denitrification is required?
1:2
2:1
3:1
5:1
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?
Same selector (Anaerobic)
Any of the above
For optimal phosphorus removal, pH should not drop below?
4.0
What condition must exist for ammonium to be converted to gaseous ammonia so it can be removed by ammonia stripping?
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
What is the term used to describe the boundary layer between two substances?
Interface
Substrate
What adverse effect can high levels of ammonia have on receiving waters?
Oxygen depletion
Algal blooms
Oxygen depletion and algal blooms
Which is an example of suspended growth denitrifaction?
Rotating biological contractor
Trickling filter
None of the above
When operating an Advanced Treatment facility using chemical treatment for solids removal, you discover high flows entering the system. You should?
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
When using polymer in a gravity thickening process for sludge, when would more polymer dosages be required? When the:
Hydraulic loading rate increases
Hydraulic loading to the unit decreases
Sludge selector speed is decreased
Solids loading to the unit decreases
When bacteria laden with phosphorous are faced with apparent death, they:
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
Head loss in a gravity filter is determined by?
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
What dosage of chlorine can be fatal in just a few breaths?
50 ppm
100 ppm
250 ppm
1000 ppm
What statement best describes at which speed a belt filter press should be operated?
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
What steps should the operator take if "washing out" occurs while operating a belt filter press?
Decrease tension on belt
Decrease wash water rate
Increase sludge rate and belt speed
Lower flow rate and increase belt speed
A problem with plastic pipe laterals resting on the surface in a spray irrigation system is?
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
FDEP approved continuous on-line analyzing of reclaimed water effluent includes analyzing for:
CBOD5
pH, chlorine, and turbidity
D.O. and temperature
Fecal Coliform and Total Coliform
Lime is used more frequently for phosphorous removal than Aluminum Sulfate because Aluminum Sulfate:
Does not settle as rapidly in clarifiers
Is more expensive than lime
Raises the pH too much
Requires anaerobic conditions and lime does not
What process control adjustment should be made when a 30 minute settleometer test shows fast solids settling leaving pin-point floc? Increase the:
Aeration rate
MLSS
RAS rate
WAS rate
According to Chapter 62-600, FAC, Domestic Wastewater facilities, the basic disinfection requirement (using chlorine) is a :
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
In an aerobic digester, excessive air rates can contribute to?
An increase in the activity of biomass
Foaming problems
High solids carry over
Reduction of the activity of biomass
A common operational problem that can occur with ammonia stripping towers involves:
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
What causes a loss of vacuum in a vacuum filter?
Change in effluent characteristics
Drum speed too low
Filter media misalignment or tear
Insufficient conditioning
According to Chapter 62-620, FAC, Wastewater Facility Permitting, the permittee shall retain treatment facility operating records for how many calendar years?
2 years
3 years
10 years
15 years
In lakes and deeper rivers, cold waters tend to slip below warmer waters because?
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
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?
6 hours
12 hours
24 hours
48 hours
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:
Chlorine in the stream mixing zone
Chlorine Contact Chamber for short circuiting
Chlorine Contact Chamber for solids scouring
Total chlorine residual analysis
How is the Fecal Coliform parameter evaluated?
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
When reading the level of a column of liquid in a graduated cylinder, burette or manometer, you should?
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
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 ?
A certified laboratory or a certified operator
Plant laborers
Plant Technicians
The permittee
What should be the pH in a rapid-mix basin for a maximum phosphorous removal efficiency when using lime?
5.0
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?
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
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?
Chlorinate to breakpoint
Decrease the flow to the steam mixing zone
Increase the chlorinator capacity
Install additional baffling
Which statement is correct concerning confined spaces?
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
If a sand drying bed has a problem with the media becoming clogged, what should the operator do first?
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
What should be the pH in a rapid-mix basin for maximum phosphorous removal efficiency when using lime?
What is the most common method of EFF disposal?
Evaporation/Percolation ponds1
In deep wells
In receiving waters
Land disposal
What would be the usual approach to measure the impact of a discharge to receiving waters?
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
What does not represent a potential hazard of working in a wastewater treatment laboratory?
Burns
Electrical shock
Hypothermia
Infectious materials
An instrument used in a laboratory that measures the intensity of color or particular wavelength is a ?
Color standard
Nephelometer
Spectrophotometer
Turbidimeter
A gravity filter experiences rapid build-up of head loss. What could be a probable cause?
Applied water flow rate too low
Incomplete backwash cycle
Media breakthrough
What problems may develop during the injection of reclaimed wastewater into deep wells?
Contamination of groundwater
Lowering of groundwater table
Saltwater intrusion
Severe hydraulic overload
According to state regulations, a wastewater plant shall maintain a pH in the effluent after disinfection within what range?
2.5 - 4.5
4.5 - 6.0
6.0 - 8.5
8.5 - 10.5
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?
Design flow and treatment type
Flow and treatment efficiency
Population and flow
Population served and treatment type
Two inorganic gases giving off the most offensive odors and which is a main concern of operators when controlling odors are?
Ammonia and skatole
Hydrogen sulfide and ammonia
Mercaptans and indole
Methane and ammonia
The recovery of a stuck anaerobic digester can be accelerated be neutralizing the acids with a caustic material like?
Aluminum sulfate
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?
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
Even though a process control test is accurately performed, which one of the following could result in meaningless findings?
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
It takes about 22% less O2 to process 1 lb of carbonaceous waste than 1 lb of nitrogenous waste. What does this indicate?
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
To determine the location and amount of lowest dissolved oxygen downstream from a wastewater effluent discharge, it is necessary to?
Conduct an annual measurment survey
Conduct an oxygen profile of the stream
Conduct an oxygen profile of the treatment plant
Observe the aquatic life
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?
The backwash water overloaded the system
The backwash time was too short
The backwash time was too long
There was excessive auxiliary scour
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?
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
Nitrification in the activated sludge process?
Decreases alkalinity and increases pH
Decreases alkalinity and pH
Increases alkalinity and pH
Increases alkalinity and decreases pH
Which statement is most correct concerning dissolved oxygen content in water?
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
Rapid accumulation on the surface of a single media sand filter results in very rapid head loss. The solution is ?
Improve prior clarification
Increase chemical coagulation
Reduce filter backwash time
Reduce the filter air scrubbing time
In the microscopic exam of the mixed liquor, you observe a dominance of rotifers and nematodes. What would this be indicative of?
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
When using break-point chlorination for ammonia removal, how many ppm of chlorine are needed to remove 1 ppm of ammonia?
1
5
8
10
Misalignment of a driver and a driven piece of equipment can cause?
Premature bearing failure
Excessive wear of the slip rings
The packing to leak
Valve chatter
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 ?
MCRT is decreasing
MCRT is increasing
Process is moving toward a more stable condition
Treatment efficiency is increasing
In a suspended growth reactor used for Denitrification
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
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?
Curing breakthroughs
Remove dissolved air which causes air binding
Removing grease and oil from the filter wells
Removing mud balls
When a 5 min observation of the settlability test indicates fast settling (e.g., 500 ml), what process change should be made?
Decrease the RAS
Increase the aeration and RAS
Increase the aeration
Increase the wasting rate
For ammonia stripping to be successful:
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
Water quality criteria for wastewater reclaimed for public access includes:
Complete lack of BOD
High level disinfection
No dissolved inorganic solids
50 mg/L TSS
What is the optimum temperature range for the nitrification process?
70 ° and 100 ° F
60 ° and 90 ° F
65 ° and 85 ° F
10 ° and 20 ° F
CO2 is stripped at pH below ___ and retained at a pH above ___
7.0 and 10
6.0 and 11
8.3 and 9.5
8.3 and 8.3
How much lime is required per ton of primary sludge?
100-200 lbs / ton
80-90 lbs / ton
150-175 lbs / ton
175-250 lbs / ton
What happens to phosphorus in a plant effluent when mixed with lime?
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
What is utilized as a carbon source?
Methanol
Aerobic bacteria
In a centrifuge series, centrate from the ____ centrifuge contains most of the phosphorus?
First
Second
Third
Last
Using ION exchange for nitrogen removal; what is the name of the resin used?
Clinoptilolite
Zemalite
Miller lite
Red line resin
Supplemental phosphorus can be provided by using what items?
Phosphoric acid
Phosphate fertilizer
Phosphoric acid and Phosphate fertilizer
Filters should be back washed at what type of flow?
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
What types of carbon food sources may be used in denitrification fixed film reactor to promote biological metabolism?
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
What may be used as a phosphorous supplement?
Dissolved triple superphosphate, phosphate fertilizer, phosphoric acid
Aqueous ammonia, anhydrous ammonia
Seed sludge
Cationic Polymers
What may be used as a nitrogen supplement?
Methanol is?
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
What do autotrophic nitrifiers use as a carbon source?
Bicarbonate alkalinity
Algae
Nitrobacter bacteria
The microorganisms do not need oxygen to metabolize methanol
What may be added to wastewater when the nutrient levels are too low to support the microorganism population?
When treating high organic loads, what process control adjustments should be made?
The DO should be kept at ____ in the first anaerobic and anoxic zones when using the Bardenpho process?
