Pregunta 1
Pregunta
In the activated sludge process, the oxidation may be by chemical or biological processes.
Pregunta 2
Pregunta
The removal of organisms from the activated sludge treatment process (sludge wasting) is a very important control technique.
Pregunta 3
Pregunta
In an air distribution system, an air metering device should be located in a straight section of the air main on the suction side of the blower.
Pregunta 4
Pregunta
In an aeration tank, the higher the food to microorganism (F/M) ratio, the more food and therefore a lower dissolved oxygen (DO) is needed.
Pregunta 5
Pregunta
When considering a major process change, first review the plant data and then make only one major change at a time.
Pregunta 6
Pregunta
Microbiology is another tool for operators to use in controlling the activated sludge process.
Pregunta 7
Pregunta
The psychrophilic bacteria in anaerobic digesters appear to be able to survive temperatures well below freezing with little or no harm.
Pregunta 8
Pregunta
Mixing is very important in a digester because it greatly speeds up the digestion rate.
Pregunta 9
Pregunta
Operators should make every effort to pump as thick a sludge to the digester as possible.
Pregunta 10
Pregunta
The withdrawal rate of sludge from a digester should be faster than a rate at which the gas production from the system is able to maintain a positive pressure in the digester.
Pregunta 11
Pregunta
Aerobic sludge digestion completes the oxidation of volatile materials in the digester.
Pregunta 12
Pregunta
The proper discharge of plant effluent is the final process for the operator.
Pregunta 13
Pregunta
The principles for collecting samples for measuring dissolved oxygen are the same as for measuring temperature.
Pregunta 14
Pregunta
Site-specific safety procedures should be confirmed with your local safety regulatory agency.
Pregunta 15
Pregunta
Always get air into the confined space before you enter to work and maintain the ventilation until you have left the space.
Pregunta 16
Pregunta
The sense of smell is reliable for evaluating the presence of dangerous gases.
Pregunta 17
Pregunta
Moving parts that create a contact hazard to employees must be guarded.
Pregunta 18
Pregunta
When applying protective coatings in a clarifier, you can create an atmospheric hazard.
Pregunta 19
Pregunta
In the laboratory, separate flammable, explosive, or special hazard items for storage in an approved manner.
Pregunta 20
Pregunta
Hard hats, safety footwear, eye protection, and hearing protection apply to all personnel in designated areas and specific jobs.
Pregunta 21
Pregunta
When you are performing plant maintenance, you must recognize tasks that may be beyond your capabilities or repair facilities, and you should request assistance when needed.
Pregunta 22
Pregunta
The horizontal pump suction piping slopes downward toward the pump.
Pregunta 23
Pregunta
Fuses are used to protect operators, wiring, main circuits, branch circuits, heaters, and motors.
Pregunta 24
Pregunta
Electric motors are the machines most commonly used to convert electrical energy into mechanical energy.
Pregunta 25
Pregunta
Valves, elbows, and other items that could disrupt the flow ahead of a meter can upset the accuracy and reliability of a flowmeter
Pregunta 26
Pregunta
Safety is just as important in the laboratory as in the rest of the treatment plant.
Pregunta 27
Pregunta
The shorter the time that elapses between sample collection and analysis, the more reliable will be the analytical results.
Pregunta 28
Pregunta
The COD test is used to measure the strength of that are too toxic for the BOD test.
Pregunta 29
Pregunta
Probably the most frequent use of computers is for word processing.
Pregunta 30
Pregunta
Wastewater flows and other characteristics that can be sensed by instruments can be monitored by computers.
Pregunta 31
Pregunta
When installing any computer program, be sure to check to see that it is doing what you expect it to do.
Pregunta 32
Pregunta
Collection of data without analysis, interpretation, and use of results is a waste of time and money.
Pregunta 33
Pregunta
Operators are likely to draw the line of best fit slightly differently as each operator will visualize a slightly different line (slope).
Pregunta 34
Pregunta
Well-kept records will make the task of writing treatment plant cost and efficiency reports much easier.
Pregunta 35
Pregunta
Records at most wastewater treatment facilities are kept daily and summarized on a monthly basis.
Pregunta 36
Pregunta
You and your plant operation are partially judged by the information contained in your report, its style, and its appearance.
Pregunta 37
Pregunta
The utility manager must provide a safer, cleaner work environment while constantly training and retraining operators to understand new technologies
Pregunta 38
Pregunta
Establishing safe work procedures for new employees is a very important function of management.
Pregunta 39
Pregunta
Good communication is an essential part of good management skills.
Pregunta 40
Pregunta
Every utility needs an effective operations and maintenance program.
Pregunta 41
Pregunta
The supervisor who has the responsibility for directing work activities must be safety conscious.
Pregunta 42
Pregunta
operator must think, act, and promote safety if the utility is to achieve a good safety record.
Pregunta 43
Pregunta
Why must the proper dissolved oxygen (DO) level be maintained in an aeration tank?
Respuesta
-
So filamentous organisms will thrive and the sludge floc will settle properly
-
So pinpoint floc will develop and be removed by the secondary clarifier
-
So the contents of the aeration tank will be thoroughly mixed
-
So the solids will settle properly and the plant effluent will be clear
Pregunta 44
Pregunta
Why should weirs installed at the outlet or effluent end of the aeration tank be level?
Respuesta
-
To comply with the plant's plans and specifications
-
To keep the aeration tank balanced
-
To prevent short-circuiting and an uneven distribution of solids in the effluent
-
To provide a uniform appearing tank
Pregunta 45
Pregunta
How can the mixed liquor suspended solids in the aeration tank be increased?
Respuesta
-
By increasing the influent flows
-
By reducing the aeration tank capacity
-
By reducing the effluent flows
-
By reducing the sludge wasting rate
Pregunta 46
Pregunta
What is bound water?
Respuesta
-
A high-molecular-weight substance that is formed by either natural or synthetic processes
-
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly
-
The gathering together of fine particles after coagulation to form larger particles by a process of gentle mixing
-
Water contained within the cell mass of sludges or strongly held on the surface of colloidal particles
Pregunta 47
Pregunta
What are raw sludge and scum?
Respuesta
-
Settled sludge solids that are removed from the bottom and the floating scum removed from the top of the aerators
-
Settled sludge solids that are removed from the bottom and the floating scum removed from the top of the clarifiers
-
Settled sludge solids that are removed from the bottom and the floating scum removed from the top of the digesters
-
Untreated solids and scum that are removed from the bar screens
Pregunta 48
Pregunta
What is the purpose of a vacuum relief valve on an anaerobic sludge digester?
Respuesta
-
Prevents a spark or flame from entering the digester
-
Prevents air from entering the digester or digester gas from escaping
-
Relieves excessive pressures in the digester so the water seal will not be blown out
-
Relieves excessive vacuums so the digester cover will not collapse
Pregunta 49
Pregunta
Which item is the key to successful digester operation?
Pregunta 50
Pregunta
Successful operation of a surface discharge system depends on which factor?
Respuesta
-
Adequate budgets to meet the essential O & M requirements
-
All operators being properly certified
-
Conscientious operators using proper techniques for sampling and analysis
-
Qualified regulators understanding the plant's O & M requirements
Pregunta 51
Pregunta
What type of emergency operating equipment should be available for pumped discharge systems when there is a loss of power?
Respuesta
-
Standby generators
-
Standby monitors
-
Standby operators
-
Standby pumps
Pregunta 52
Pregunta
What is a representative sample?
Respuesta
-
A collection of individual samples obtained at regular intervals, usually every one or two hours during a 24-hour time span
-
A collection of samples combined with other samples in proportion to the rate of flow when the sample was collected
-
A sample portion of material, water, or wastestream that is as nearly identical in content and consistency as possible to that in the larger body being sampled
-
A single sample of water collected at a particular time and place that represents the composition of the water only at that time and place
Pregunta 53
Pregunta
What is the best protection against the risk of infections and infectious diseases?
Pregunta 54
Pregunta
What is the ideal method of dealing with any high-noise environment?
Respuesta
-
The elimination or reduction of all sources through feasible engineering or administrative controls
-
The scheduling of work in the high-noise environment when the equipment is not operating
-
The selection of operators with a high level of noise tolerance to work in the high-noise environment
-
The use of generous compensation packages when loss of hearing results
Pregunta 55
Pregunta
What is the apparent cause of drowning when someone falls into a diffused aeration tank?
Respuesta
-
A strong undertow pulls the person under
-
The aerator is too deep for a person to stand on the bottom
-
The air in the water causes the person to sink to the bottom
-
There is nothing to grab hold of to keep afloat or to pull oneself out of the aerator
Pregunta 56
Pregunta
If your hands may come in contact with wastewater or sludge during sampling, how can you prevent the spread of disease?
Respuesta
-
Dry hands in the sunlight when you have finished sampling
-
Wear disposable, impervious gloves
-
Wear heavy leather gloves
-
Wear light, flexible, cotton gloves
Pregunta 57
Pregunta
Which materials are consumed by a Class B fire?
Respuesta
-
Combustible metals, such as magnesium, sodium, zinc, and potassium
-
Energized electrical equipment, such as starters, breakers, and motors
-
Flammable and combustible liquids, such as gasoline,oil, and grease
-
Ordinary combustibles, such as wood, paper, and cloth
Pregunta 58
Pregunta
Why is a good maintenance program essential for a wastewater treatment plant?
Respuesta
-
So operators can maintain their operator maintenance certificates
-
So operators will have time to conduct plant tours
-
To arrange for equipment vendors to observe their products
-
To operate continuously at peak design efficiency
Pregunta 59
Pregunta
How can pipelines that carry chlorine gas be purged to remove moisture?
Pregunta 60
Pregunta
Why do very few maintenance operators do the actual electrical repairs or troubleshooting?
Respuesta
-
Because cost-effective training programs are rarely available for maintenance operators
-
Because highly trained technicians are readily available at a lower cost than maintenance operators
-
Because this is a highly specialized field and unqualified people can seriously injure themselves and
damage costly equipment
-
Because union regulations and negotiations forbid maintenance operators from performing this work
Pregunta 61
Pregunta
What is voltage? Voltage is
Respuesta
-
A measure of power units used to rate electrical machines or motors or to indicate power in an electric circuit
-
A practical unit of electrical resistance
-
The electrical pressure available to cause a flow of current when an electric circuit is closed
-
The measurement of current or electron flow and is an indication of work being done
Pregunta 62
Respuesta
-
A device that allows a motor to be run continuously at its rated horsepower without causing damage to the insulation system
-
A protective device having a strip or wire of fusible metal which, when placed in a circuit, will melt and break the electric circuit when subjected to an excessive temperature
-
A switch that is opened automatically when the current or voltage exceeds or falls below a certain limit
-
An expression representing an electrical connection to earth or a large conductor that is at the earth's potential or neutral voltage
Pregunta 63
Pregunta
When two or more pumps of the same size are installed, why should they be operated alternately?
Respuesta
-
To ensure that all the pumps will fail simultaneously and can be replaced all at once
-
To equalize wear, keep the motor windings dry, and distribute lubricant in the bearings
-
To keep the load on the foundation and flow in the pipes balanced
-
To minimize electricity consumption and system electrical hazards
Pregunta 64
Pregunta
What do flow measurement transmitter instruments do?
Respuesta
-
Compare received signals with other values and send corrective or adjusting signals when necessary
-
Measure the variable flow indicator and convert this value to a usable number
-
Pick up the transmitted signal and convert it to a usable number
-
Send the flow variable to another device for conversion to a usable number
Pregunta 65
Pregunta
Why should operators review the plans and specifications for pumps and lift stations?
Respuesta
-
To be sure adequate provisions have been made for the station pumps, equipment, and instrumentation to be easily and properly operated and maintained
-
To review the plans and specifications to ensure receipt of low bids
-
To suggest contractors who could do an acceptable job
-
To verify and confirm the consulting engineers' calculations
Pregunta 66
Pregunta
In chemistry, to what does normality (N) refer?
Respuesta
-
Solution hazard
-
Solution strength
-
Solution toxicity
-
Solution volume
Pregunta 67
Pregunta
What does the digester supernatant solids test measure?
Respuesta
-
The degree of liquid-solids separation occurring when mixing is stopped in the digester
-
The effectiveness of the digester mixing procedures
-
The percent of settleable solids being returned to the plant headworks
-
The strength of the supernatant that is removed from the digester
Pregunta 68
Pregunta
Why should chlorine residual be removed before final discharge to a receiving stream?
Respuesta
-
For protection of aquatic vegetation from toxic chemicals
-
For protection of fish and other aquatic life
-
For protection of swimmers from skin rashes
-
For protection of water supplies from TTHMs
Pregunta 69
Pregunta
What is aseptic?
Respuesta
-
A plastic tube that contains an exact amount of chemical or reagent
-
A representative portion of a sample. Often, an equally divided portion of a sample
-
A solution or liquid whose chemical makeup neutralizes acids or bases without a great change in pH
-
Free from the living germs of disease, fermentation, or putrefaction. Sterile
Pregunta 70
Pregunta
What is the first question an operator should ask when considering the possibility of using a computer or expanding the use of computers?
Respuesta
-
How can I find a computer course to improve my computer skills?
-
How can I find funds in the budget to help me?
-
How can I get the computer staff to assist me?
-
How can I use a computer to help me do a better job?
Pregunta 71
Pregunta
What does a SCADA system do?
Respuesta
-
Collects, stores, and analyzes information about all aspects of O & M, transmits alarm signals when necessary, and allows fingertip control of alarms, equipment, and processes
-
Provides standby power to operate critical pumps when power systems fail
-
Scans plant facilities and reports unusual conditions to plant security
-
Surveys stakeholders and system users and reports
Pregunta 72
Pregunta
What is the median?
Respuesta
-
The difference between the largest and smallest measurement
-
The measurement that occurs most frequently
-
The middle measurement when the measurements are ranked in order of magnitude (size)
-
The sum of all measurements divided by the number of measurements.
Pregunta 73
Pregunta
What is a normal distribution of data?
Respuesta
-
The geometric mean describes the distribution
-
The mean, median, and mode values are different
-
The mean, median, and mode values will be be approximately the same
-
The percentile plotting points are different
Pregunta 74
Pregunta
What is the main means by which operators who have information communicate with those who need it?
Respuesta
-
Committee meetings
-
Professional conferences
-
Report writing
-
Telephones
Pregunta 75
Pregunta
Recorded data should enable the operator to determine how to perform which task?
Respuesta
-
Develop tailgate safety sessions
-
Operate and maintain the plant
-
Promote qualified operators
-
Schedule plant tours
Pregunta 76
Pregunta
What is planning?
Respuesta
-
Deciding who does what work and delegating authority to the appropriate operators
-
Determining the goals, policies, procedures, and other elements to achieve the goals and objectives of the agency
-
Guiding, teaching, motivating, and supervising operators and utility staff members
-
Taking the steps necessary to ensure that essential activities are performed so that objectives will be achieved as planned
Pregunta 77
Pregunta
What is authority?
Respuesta
-
Answering to those above in the chain of command to explain how and why you have used your authority
-
The act in which power is given to another person in the organization to accomplish a specific job
-
The power and resources to do a specific job or to get that job done
-
When a manager gives power or responsibility to an employee, the employee ensures that the manager is informed of results or events
Pregunta 78
Pregunta
How do you measure financial stability for a utility?
Respuesta
-
By calculating the benefit/cost ratio for the utility
-
By calculating the net revenue for the utility
-
By calculating the operating ratio and the coverage ratio
-
By calculating the rate of return on the utility's assets
Pregunta 79
Pregunta
What is the operating ratio?
Respuesta
-
A measure of the ability of the utility to pay the principal and interest on loans and bonds in addition to any unexpected expenses
-
A measure of the total revenues divided by the total operating expenses
-
The amount of money required annually to pay the interest on outstanding debts
-
The rate of return on the funds expended on facilities
Pregunta 80
Respuesta
-
A computer analytical system that continuously monitors water quality changes in the system
-
A computer budgeting system that records and monitors costs and revenues
-
A computer intelligence system that eliminates many tasks performed by operators
-
A computer-monitored alarm, response, control, and data acquisition system used to monitor and adjust the operation of equipment
Pregunta 81
Pregunta
What is the purpose of a safety policy statement?
Respuesta
-
To comply with OSHA regulations
-
To create the proper atmosphere to impress insurance companies
-
To let employees know that the safety program has the full support of the agency and its management
-
To let the media and the public know that the agency is safety conscious
Pregunta 82
Pregunta
When wastewater enters an activated sludge plant, the preliminary treatment processes remove which pollutants?
Respuesta
-
Coarse or heavy solids (grit)
-
Debris, such as roots, rags, and boards
-
Floatable and settleable material
-
Nutrients
-
Soluble or finely divided suspended materials
Pregunta 83
Pregunta
Which items can cause an unsuitable environment for the activated sludge process?
Respuesta
-
Failure to supply enough oxygen
-
High concentrations of acids, bases, and other toxic substances
-
Maintaining proper solids (floc mass) concentration in the aerator
-
Proper adjustment of the waste sludge pumping rate
-
Uneven flows of wastewater, which can cause overfeeding or starvation
Pregunta 84
Pregunta
What information should be recorded when testing pumps?
Respuesta
-
Date of the test
-
Location of the pump
-
Name of the operator
-
Pump discharge (flow)
-
Pump discharge pressure
Pregunta 85
Pregunta
Which plant changes could cause an activated sludge plant to become upset?
Respuesta
-
Changes in operators' shifts
-
Changes in the sampling program
-
Flow or waste changes
-
High solids in the digester supernatant
-
Temperature changes
Pregunta 86
Pregunta
Which items are possible causes of sludge bulking?
Respuesta
-
Filamentous organisms growing from one floc mass to another
-
Low DO
-
Low nutrient concentrations
-
Low pH
-
Production of a highly jelly-like, waterlogged sludge that has a very low sludge density
Pregunta 87
Pregunta
Which items should be checked before starting a new sequencing batch reactor (SBR) plant?
Respuesta
-
Be sure the plant has an up-to-date O & M manual and a set of as-built plans (record drawings)
-
Check and flush pipe systems and remove any refuse or debris left in them during construction
-
Ensure protective safety guards are installed on rotating equipment, open tanks, and channels
-
Make sure tanks are clean; be sure all debris, boards,ladders, and tools have been removed
-
To the extent possible, operate and test all equipment before admitting wastewater for treatment
Pregunta 88
Pregunta
Operators can achieve good digester operation by controlling which items?
Respuesta
-
Loading rate or food supply (organic solids)
-
Mixing
-
Reproduction rate of acid formers and methane fermenters
-
Temperature
-
Volatile acid/alkalinity relationship
Pregunta 89
Pregunta
How can a scum blanket be controlled in a digester?
Respuesta
-
By adequate mixing
-
By chemicals
-
By heat
-
By methane fermenters
-
By volatile acids
Pregunta 90
Pregunta
Where does struvite scale sometimes form?
Respuesta
-
In anaerobic digesters
-
In downstream chlorination equipment
-
In downstream digested sludge concentration equipment
-
In downstream digested sludge handling equipment
-
In downstream effluent weirs
Pregunta 91
Pregunta
When operators are making their rounds inspecting their plant, they should be alert and investigate and record
which items? Anything that
Pregunta 92
Pregunta
What types of problems are encountered when operating aerobic digesters?
Respuesta
-
Floating sludge
-
Fluctuating BODs
-
Odors
-
Scum
-
Wet solids
Pregunta 93
Pregunta
When reviewing the specifications for sludge digestion and solids handling facilities, which items should operators check?
Respuesta
-
Adequate supply of equipment operation and maintenance manuals
-
Equipment warranties and responsibility for acceptance testing
-
Instrumentation—remote and local control board items and recorders are provided
-
Paints and protective coatings
-
Performance requirements and capabilities
Pregunta 94
Pregunta
Prior to discharge to surface waters, why must wastewater be treated?
Respuesta
-
To prevent nuisances due to odors or unsightliness
-
To prevent the wastewater from interfering with the many uses of surface waters
-
To produce documentation for the record keeping system
-
To protect the health of the people who may come in contact with it
-
To provide water for discharge sampling and analysis
Pregunta 95
Pregunta
Which operating procedures should be developed for the start-up of a plant?
Respuesta
-
Inspect the discharge line, where possible
-
Look at the water surface over the diffuser or outfall pipe
-
Observe the flow entering the discharge system for visible pollutants
-
Open all appropriate valves
-
Start the pumps (unless it is a gravity system)
Pregunta 96
Pregunta
Which items are probable causes of floatables in pond effluents?
Respuesta
-
Excessive floatables and scum on the surface
-
Excessive solids accumulated on the bottom have gasified and floated to the surface
-
Excessive velocity or insufficient detention time
-
Outlet baffle is not at the proper location
-
Temperature or weather conditions may favor a particular species of algae
Pregunta 97
Pregunta
Under what conditions may the frequency of sampling be increased?
Respuesta
-
When the lab is not meeting QA/QC requirements
-
When the lab staff have the opportunity to analyze more samples
-
When the receiving waters are not meeting established water quality standards
-
When the treatment plant effluent is not meeting discharge requirements
-
When the treatment plant staff increases and more time is available to collect more samples
Pregunta 98
Pregunta
A confined space may be defined as any space that meets Which conditions?
Respuesta
-
Allows more than one employee to fit into the space and work
-
Has limited or restricted means for entry or exit
-
Is large enough and so configured that an employee can bodily enter and perform assigned work
-
Is not designed for continuous employee occupancy
-
Requires employees to wear personal protective equipment (PPE)
Pregunta 99
Pregunta
The hazard warnings on containers of hazardous chemicals at your plant should contain emergency guide information on which specific categories?
Respuesta
-
Flammability
-
Health
-
Nutrients
-
Permeability
-
Reactivity
Pregunta 100
Pregunta
Which items could be included in your plant's fire prevention plan?
Respuesta
-
Develop written response procedures for reacting to a fire situation, to include evacuation
-
Provide periodic cleanup of weeds or other vegetation in and around the plant
-
Provide required service on all fire detection and response equipment (inspection, service, hydrostatic
-
Regulate the use, storage, and disposal of all combustible materials/substances
-
Routinely inspect fire doors to ensure proper operation and unobstructed access
Pregunta 101
Pregunta
The primary use for polymers in wastewater treatment is the conditioning of sludge to facilitate removal of water in
which subsequent treatment processes?
Pregunta 102
Pregunta
Working safely in the laboratory involves which basic safety procedures and practices?
Respuesta
-
Always check labels on bottles to make sure that the proper chemical is selected
-
Never handle chemicals with your bare hands
-
Never use laboratory glassware for a cup or food dish
-
Use care in making rubber-to-glass connections
-
Use proper safety goggles or a face shield in all tests where there is danger to the eyes
Pregunta 103
Pregunta
Which paperwork items can be helpful in identifying the causes of accidents and developing corrective procedures?
Pregunta 104
Pregunta
What could cause a pump to run dry?
Respuesta
-
Excessive leakage when pumping against a high head
-
Holes (spacing) being too large in the suction intake screen
-
Impeller rotating too fast and causing cavitation
-
Lack of proper priming when starting
-
Loss of suction when operating
Pregunta 105
Pregunta
Which items are primary sources of unsatisfactory AC brush and ring performance?
Respuesta
-
Disturbing external condition
-
Improper load or service condition
-
Mechanical fault in the machine
-
Poor machine design
-
Poor preparation and care of the machine
Pregunta 106
Pregunta
When performing pump station electrical equipment maintenance tasks, which items should be checked and inspected annually?
Pregunta 107
Pregunta
Which items are causes of motor malfunction or failure?
Respuesta
-
Bearing failures
-
Contaminants
-
Old age
-
Overload (thermal)
-
Single phasing
Pregunta 108
Pregunta
When troubleshooting any motor control that has developed trouble, the qualified maintenance operator should be able to do which of the following?
Respuesta
-
Examine all unusual factors
-
Find the cause of the problem
-
Know what should happen when a switch is pushed
-
Make a visual inspection
-
Repair the problem and eliminate the cause, if possible
Pregunta 109
Pregunta
Plugged pipelines are encountered in lines transporting which types of materials and liquids?
Respuesta
-
Digested sludge
-
Effluent
-
Grit
-
Raw sludge
-
Scum
Pregunta 110
Pregunta
Which factors will cause sludge lines to plug more often?
Respuesta
-
When industrial wastes are discharged after a fine screening process
-
When plant effluent and reclaimed effluent are pumped through the lines
-
When RAS (return activated sludge) and WAS (waste activated sludge) are pumped through the lines
-
When scum and raw sludge are pumped through the same line
-
When stormwaters carry in grit and silt that are not effectively removed by the grit removal facilities
Pregunta 111
Pregunta
When examining lift station prints, operators should ensure adequate provisions have been made for which items?
Respuesta
-
Floors should be sloped to provide drainage, where needed, and drains should be located in low spots
-
Overhead clearances of power lines, trees, and roofs should be adequate for a crane to remove large equipment
-
The alarm system should signal high water levels in the wet well and water on the floor of the dry well
-
There should be room to use hydrolifts, cranes, and high-velocity cleaners, as needed
-
There should be sufficient room to set up portable pumping units or other necessary equipment in cases of major station failures or disasters
Pregunta 112
Pregunta
When working with chemicals and other materials in the wastewater treatment plant laboratory, which hazards can
be minimized by using proper techniques and equipment?
Respuesta
-
Burns
-
Electric shock
-
Infectious materials
-
Poisons
-
Toxic fumes
Pregunta 113
Pregunta
Why must hydrogen sulfide gas be measured in the atmosphere?
Respuesta
-
Because it causes corrosion
-
Because it causes odors
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Because it increases the fuel value of sewer gas
-
Because it is flammable and explosive under certain conditions
-
Because it is toxic to your respiratory system
Pregunta 114
Pregunta
Which precautions should be considered when measuring the chemical oxygen demand (COD) of a sample?
Respuesta
-
Flasks and condensers should be clean and free from grease or other oxidizable materials
-
The standard ferrous ammonium sulfate solution is unstable and should be standardized daily
-
The wastewater sample should be well mixed
-
Use a wide-tip pipet to ensure a representative sample is added
-
Use extreme caution and safety precautions when handling the chemicals used for the test
Pregunta 115
Pregunta
Which precautions should be considered when using a dissolved oxygen (DO) probe?
Respuesta
-
Dissolved inorganic salts, such as found in seawater, can influence the readings from a probe
-
Do not place the probe directly over a diffuser because you want to measure the dissolved oxygen in the water being treated, not the oxygen in the air supply to the aerator
-
Keep the membrane in the tip of the probe from drying out
-
Periodically check the calibration of the probe
-
Reactive compounds, such as reactive gases and sulfur compounds, can interfere with the output of a probe
Pregunta 116
Pregunta
Sulfate ions in wastewater are indirectly responsible for which serious problems?
Respuesta
-
Indigestion
-
Laxative effects
-
Odor
-
Sewer corrosion problems
-
Toxic gas
Pregunta 117
Pregunta
Which items are general types of computer applications in wastewater treatment plants??
Respuesta
-
Communications
-
Data analysis
-
Recordkeeping
-
Report generation
-
Systems monitoring
Pregunta 118
Pregunta
If the proper lab results are entered into the computer, the computer can calculate and print out which items?
Respuesta
-
Chemical dosages
-
F/Ms (Food to Microorganism ratios)
-
MCRTs (Mean Cell Residence Times)
-
Percent removals
-
Suspended solids, BOD, or COD loadings
Pregunta 119
Pregunta
Which programs are typically included in general purpose software packages?
Respuesta
-
Database management
-
Graphics
-
Plant template
-
Spreadsheet
-
Word processing
Pregunta 120
Pregunta
Which items can typically be monitored, recorded, and controlled by computers in a wastewater treatment plant?
Respuesta
-
Aeration basin dissolved oxygen
-
Anaerobic sludge digester gas production
-
Chlorine contact time
-
Influent flow control gates and valves
-
Secondary clarifier sludge pumping
Pregunta 121
Pregunta
When preparing to plot data in a bar graph, what information must first be determined?
Pregunta 122
Pregunta
Why are records important?
Respuesta
-
They are needed to fill unused space in storage rooms and filing cabinets
-
They are needed to show the type and frequency of maintenance and to evaluate the effectiveness of maintenance programs
-
They can indicate plant efficiency, performance, past problems, and potential problems
-
They can provide data upon which to base recommendations for modifying plant operation and facilities
-
They may be needed in damage suits brought against the district or municipality
Pregunta 123
Pregunta
A list of the minimum daily records kept at a fairly large treatment plant with digester tanks may include which items?
Respuesta
-
Chlorine use (lbs or kg)
-
Influent and effluent temperatures
-
pH of influent and effluent
-
Precipitation and air temperature
-
Raw wastewater flow (MGD from totalizer)
Pregunta 124
Pregunta
Which items are basic principles common to good report writing?
Respuesta
-
Know the purpose and objective of your report
-
Know your subject
-
Omit any recommendations
-
Organize the report to present your ideas in a logical order
-
Tailor your report to the person or persons to whom it is directed
Pregunta 125
Pregunta
Which items are guidelines for preparing a report?
Respuesta
-
Arrange the ideas in a logical sequence
-
Begin writing
-
Gather material needed to support the ideas to be presented in the report
-
List ideas and topics you plan to cover in the report
-
Prepare conclusions and recommendations after writing the main body of the report
Pregunta 126
Pregunta
The utility manager's staffing responsibilities include which tasks?
Respuesta
-
Evaluating employee performance
-
Issuing orders and instructions
-
Providing opportunities for advancement for operators and staff
-
Selecting and training employees
-
Teaching classes
Pregunta 127
Pregunta
Which items are important steps in the process of hiring and selecting a new operator?
Pregunta 128
Pregunta
Which items may serve as a guide for both the employee and the supervisor when dealing with a confrontation regarding employee performance issues?
Respuesta
-
Aim for a permanent solution
-
Create a private environment
-
Keep your language appropriate
-
Listen very carefully
-
Maintain an adult approach
Pregunta 129
Pregunta
The total revenue of a utility comes from revenue generated by which sources?
Respuesta
-
Chemicals
-
Hook-up charges
-
Interest income
-
Taxes or assessments
-
User fees
Pregunta 130
Pregunta
What is predictive maintenance?
Respuesta
-
A method of establishing baseline performance data
-
Monitoring performance criteria over a period of time
-
Observing changes in performance so that failure can be predicted and maintenance can be performed on a planned, scheduled basis
-
The same as corrective maintenance
-
The same as proactive maintenance
Pregunta 131
Pregunta
How can a supervisor be partially or fully responsible for an accident?
Respuesta
-
By causing unsafe acts to take place
-
By disregarding an unsafe work environment
-
By overlooking or failing to consider any number of safety hazards
-
By requiring operators to follow safe procedures
-
By requiring work to be performed in haste