CA Water Treatment Plant Operator Quiz Chapter 6

60 Questions | Total Attempts: 1886

Settings
Please wait...
CA Water Treatment Plant Operator Quiz Chapter 6

Filtration Water Treatment Plant Operation Volume 1 Sixth Edition Please let me know if there are any issues with the quiz such as typos, wrong answers, etc. .


Questions and Answers
  • 1. 
    The removal of mechanisms that apply to slow sand siltration are directly comparable to those used in rapid san filtration.
    • A. 

      True

    • B. 

      False

  • 2. 
    The relationship between turbidity breakthrough and limiting head loss is strongly affected by optimum chemical treatment.
    • A. 

      True

    • B. 

      False

  • 3. 
    Media with high uniformity coefficients are composed of more uniform particles.
    • A. 

      True

    • B. 

      False

  • 4. 
    Pressure filter media are fully enclosed and it is very difficult to assess he media condition by simple visual observation.
    • A. 

      True

    • B. 

      False

  • 5. 
    A filter is usually operated until just before clogging or breakthrough occurs.
    • A. 

      True

    • B. 

      False

  • 6. 
    In order to save money, energy, and water by maximizing production before backwashing, operators should run their filters until clogging or breakthrough occurs.
    • A. 

      True

    • B. 

      False

  • 7. 
    Floc that is too large will cause the top portion of the filter bed to clog rapidly, thus leading to short filter runs.
    • A. 

      True

    • B. 

      False

  • 8. 
    If a turbidimeter is provided with an alarm feature, virtually instantaneous response to process failures can be achieved.
    • A. 

      True

    • B. 

      False

  • 9. 
    Operators can "bump" a filter to increase the length of the filter run and to avoid backwashing.
    • A. 

      True

    • B. 

      False

  • 10. 
    A quick determination of filtration removal efficiency can be made by comparing filter influent and effluent turbidity levels with those of recent record.
    • A. 

      True

    • B. 

      False

  • 11. 
    Proper surface washing of filter beds should prevent mudball formation.
    • A. 

      True

    • B. 

      False

  • 12. 
    Usually, when the backwash water coming up through the filter becomes clear, the media is clean.
    • A. 

      True

    • B. 

      False

  • 13. 
    To demonstrate log removals of Giardia cysts and viruses, a water system may use particle counting as a substitute for Giardia cyst measurement.
    • A. 

      True

    • B. 

      False

  • 14. 
    A particle counter can tell the difference between a particle of clay and a microorganism (protozoan cysts or oocysts).
    • A. 

      True

    • B. 

      False

  • 15. 
    Particle counts and particle size distribution analyses present an informative picture of effluent quality produced during the filter ripening phase after a filter has been backwashed.
    • A. 

      True

    • B. 

      False

  • 16. 
    With lengthening filter run time, the percentage of large particles passing through the filter often decreases while small particles increase.
    • A. 

      True

    • B. 

      False

  • 17. 
    Turbidity readings provide an indication of the number or size of particles.
    • A. 

      True

    • B. 

      False

  • 18. 
    Particle counts can be correlated with turbidity.
    • A. 

      True

    • B. 

      False

  • 19. 
    What is the purpose of filtration?
    • A. 

      The removal of iron and manganese from the water being treated

    • B. 

      The removal of particulate impurities and floc from the water being treated

    • C. 

      The removal of pathogens from the water being treated

    • D. 

      The removal of tastes and odors from the water being treated

  • 20. 
    What are particulates?
    • A. 

      Clumps of bacteria and particulate impurities that have come together and formed a cluster

    • B. 

      Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge

    • C. 

      Very small open spaces in a rock or granular material

    • D. 

      Very small solids suspend in water which can vary widely in size, shape, density, and electrical charge

  • 21. 
    What is absorption?
    • A. 

      The gathering of a gas, liquid, or dissolved substance on the surface or interface zone of another material

    • B. 

      The sedimentation of particulates in very small spaces in a rock or granular material

    • C. 

      The straining of particles through the pores in a filter

    • D. 

      The taking in or soaking up of one substance into the body of another by molecular or chemical action

  • 22. 
    • A. 

      The gathering of a gas, liquid, or dissolved substance on the surface or interface zone of another material.

    • B. 

      The sedimentation of particulates in very small spaces in a rock or granulated material

    • C. 

      The straining of particles through the pores in a filter

    • D. 

      The taking in or soaking up of one substance into the body of another by molecular or chemical action

  • 23. 
    Why is slow sand filtration popular for small systems?
    • A. 

      Because of high quality source water

    • B. 

      Because of low demands for water

    • C. 

      Because of reliability and minimum operation and maintenance requirements

    • D. 

      Because of the availability of slow sand

  • 24. 
    What is the filter production rate?
    • A. 

      A measure of the amount of water that can be processed through an individual filter module in a given time period

    • B. 

      A measure of the flow of water through a filter

    • C. 

      A measure of the head loss through a filter

    • D. 

      A measure of the velocity of water flowing down through a filter

  • 25. 
    • A. 

      Keep the filters clean by backwashing

    • B. 

      Minimize the head loss through the filters

    • C. 

      Perform the jar tests on a regular basis

    • D. 

      Select an effluent turbidity goal (level) and stay below the target value

  • 26. 
    What is filter backwashing?
    • A. 

      A buildup of head loss (pressure drop) across the filter media until it reaches some predetermined design limit

    • B. 

      A crack or break in a filter bed allowing the passage of floc or particulate matter through a filter

    • C. 

      A mass of solid particles that is made to flow like a liquid by injection of water

    • D. 

      A process of reversing the flow of the water through the filter media to remove the entrapped solids

  • 27. 
    Why should operators avoid running their filters until clogging or breakthrough occurs?
    • A. 

      Because clogging or breakthrough will increase filter maintenance requirements

    • B. 

      Because clogging or breakthrough will require additional space for sludge disposal

    • C. 

      Because clogging or breakthrough will require more backwash water

    • D. 

      Because when breakthrough occurs, there will be an increase in filtered water turbidity

  • 28. 
    Why are surface wash systems usually required for filtration systems?
    • A. 

      In order to cleanse the filtered water before disinfection (chlorination)

    • B. 

      In order to encourage mudball formation for subsequent removal

    • C. 

      In order to produce optimum cleaning of the filter media during backwashing and to prevent mudballs

    • D. 

      In order to reduce the volume of backwash water required

  • 29. 
    How does the rate-of-flow  filter control system work?
    • A. 

      Each filter effluent control valve is connected to a flow-meter and, as the filter run continues and the media begins to clog, the control valve slowly opens to maintain a constant flow of water through the filter

    • B. 

      The flow rate varies with head loss and each filter operates at the same, but variable, water surface level

    • C. 

      The flow to each filter influent is split or divided to each weir and equal flow is automatically distributed to each filter

    • D. 

      The influent flow to each filter is divided by a weir and the water surface level in each filter varies according to headloss, but the flow rate remains constant for each filter

  • 30. 
    What is the "ripening period" for a filter?
    • A. 

      When applications of the floc build up on the material previously deposited on the media surface

    • B. 

      When the floc buildup causes taste and odors

    • C. 

      When the floc buildup on the filter media degrades

    • D. 

      When the period of floc buildup reaches excessive headloss

  • 31. 
    • A. 

      At filtration rates when filtered water has high turbidity levels

    • B. 

      At filtration rates when mudballs tend to form during backwash

    • C. 

      At high filtration rates when iron and alum floc will shear in the pores of the filter and short filter runs will result because of turbidity breakthrough

    • D. 

      At high filtration rates when there is insufficient water in the backwash water tank

  • 32. 
    What is the best way to compare filter runs? By using the
    • A. 

      Effluent turbidity levels

    • B. 

      Length of the filtration cycle

    • C. 

      Unit Filter Run Volume (UFRV) technigue

    • D. 

      Volume of backwash water per cycle

  • 33. 
    Why should filter washing begin slowly?
    • A. 

      To allow filter boils to develop uniformly

    • B. 

      To ensure the loss of light of small-diameter filter media

    • C. 

      To permit purging (removing) of any entrapped air from the filter media, and also to provide uniform expansion of the filter bed

    • D. 

      To prevent damage from water hammer

  • 34. 
    What is a particle counter?
    • A. 

      A device which calibrates turbidimeters

    • B. 

      A device which counts and measures the size of individual particles in water

    • C. 

      A device which identifies the origin or source of particles

    • D. 

      A device which measures turbidity

  • 35. 
    The high sensitivity of the particle counter makes which sampling tasks critical for proper operation?
    • A. 

      Handling and delivery

    • B. 

      Preservation and storage

    • C. 

      Retrieval and delivery

    • D. 

      Storage and retrieval

  • 36. 
    The interrelated removal mechanisms within the filter media include which processes?
    • A. 

      Absorption

    • B. 

      Adsorption

    • C. 

      Biological action

    • D. 

      Sedimentation on the media

    • E. 

      Straining

  • 37. 
    • A. 

      Dual media (sand and anthracite coal)

    • B. 

      Impermeable media (clay)

    • C. 

      Multi- or mixed media (sand, anthracite coal, and garnet)

    • D. 

      Permeable media (gravel)

    • E. 

      Single media (sand)

  • 38. 
    How are particles removed from the water in the slow sand filtration process?
    • A. 

      Adsorption

    • B. 

      Biological action

    • C. 

      Flocculation

    • D. 

      Precipitation

    • E. 

      Straining

  • 39. 
    • A. 

      An adequate supply of the filter aid chemical may not be readily available

    • B. 

      Extra safety precautions must be taken with higher filter aid chemical feed rates

    • C. 

      Overdosing can cause a violation of the MCL

    • D. 

      Overdosing can cause sealing of a filter media resulting in drastically shortened filter runs

  • 40. 
    Which factors are desirable filter media characteristics?
    • A. 

      Does not react with substances in the water (is inert and easy to clean up)

    • B. 

      Free of impurities

    • C. 

      Good hydraulic characteristics (is permeable)

    • D. 

      Hard and durable

    • E. 

      Insoluble in water

  • 41. 
    • A. 

      Effectiveness of the pretreatment process in conditioning the suspended solids for removal by sedimentation and filtration

    • B. 

      Filter operation

    • C. 

      Quality of the water being treated

    • D. 

      Recordkeeping program

    • E. 

      Weather conditions

  • 42. 
    The degree of pretreatment applied prior to filtration depends on which factors?
    • A. 

      Age of the treatment facility

    • B. 

      Operator training program

    • C. 

      Preference of the regulatory agency

    • D. 

      Size of the treatment facility

    • E. 

      Type of treatment plant (filtration system)

  • 43. 
    Direct filtration is considered a feasible alternative to conventional filtration when source waters are low in which constituents?
    • A. 

      Coliform organisms

    • B. 

      Color

    • C. 

      Nutrients

    • D. 

      Plankton

    • E. 

      Turbidity

  • 44. 
    • A. 

      Checking and adjusting process equipment (changing chemical feed rates)

    • B. 

      Evaluating filter media condition (media loss, mudballs, cracking)

    • C. 

      Evaluating water quality conditions (turbidity) and making appropriate process changes

    • D. 

      Monitoring process performance

    • E. 

      Visually inspecting facilities

  • 45. 
    • A. 

      Checking the filter media condition

    • B. 

      Checking the filtration process and backwash equipment condition

    • C. 

      Inspecting the facilities

    • D. 

      Making visual observations of the backwash operation

    • E. 

      Operating the filters and backwash

  • 46. 
    • A. 

      Immediately contact the consumer (stakeholders)

    • B. 

      Immediately enroll in an appropriate training course

    • C. 

      Immediately notify the news media

    • D. 

      Immediately review the performance of the filtration process

    • E. 

      Immediately Immediately review the pretreatment process (coagulation, flocculation, and sedimentation)

  • 47. 
    • A. 

      Failure of the filter to come clean during the backwash process

    • B. 

      Lack of turbidity in the backwash water

    • C. 

      Low backwash head loss

    • D. 

      Media boils

    • E. 

      Media loss

  • 48. 
    • A. 

      By adjusting backwash flow rates

    • B. 

      By adjusting backwash surface wash duration

    • C. 

      By adjusting backwash surface wash flow rates

    • D. 

      By adjusting the duration of the backwash cycle

    • E. 

      By adjusting the time sequence of the backwash cycle

  • 49. 
    Filters are routinely taken off line under which conditions?
    • A. 

      For backwashing when the media becomes clogged with particulates

    • B. 

      For backwashing when turbidity breakthrough occurs

    • C. 

      When a building fire is reported

    • D. 

      When demands for water are reduced

    • E. 

      When it is necessary to decrease filtration rates

  • 50. 
    After start-up of a backwash pump, operators should always check for which items?
    • A. 

      Excessive noise

    • B. 

      Excessive vibration

    • C. 

      Leakage (water, lubricants)

    • D. 

      Overheating

    • E. 

      Volute flow

  • 51. 
    When working around filtration equipment such as pumps and motors, which items are potential safety hazards?
    • A. 

      Electrical equipment

    • B. 

      Mechanical equipment

    • C. 

      Open-surface filters

    • D. 

      Pathogenic organisms

    • E. 

      Valve and pump vaults, sumps, and filter galleries

  • 52. 
    Particle counting, when used in conjunction with other measurement techniques, can be valuable tool to diagnose what kinds of filtration problems?
    • A. 

      Disrupted media

    • B. 

      Improperly graded media

    • C. 

      Insufficient media

    • D. 

      Mudballs

    • E. 

      Short-circuiting

  • 53. 
    When using grab samplers with particle counters, why do operators often use short lengths of Tygon tubing for the sample tubing, Because it is
    • A. 

      Easy to buy in various essential lengths

    • B. 

      Easy to see the sample flow

    • C. 

      Easy to work with

    • D. 

      Flexible

    • E. 

      Inexpensive

  • 54. 
    Which items could cause the particle concentration to appear high?
    • A. 

      Air bubbles

    • B. 

      Contamination

    • C. 

      Decreased flow rate through the sensor

    • D. 

      Degasification

    • E. 

      Increased flow rate through the sensor

  • 55. 
    If the head of water on the filter media of a gravity filter is 3.5 feet, what is the pressure on the media surface in pounds per square inch (psi)?
    • A. 

      1.3 psi

    • B. 

      1.5 psi

    • C. 

      1.7 psi

    • D. 

      1.9 psi

    • E. 

      2.2 psi

  • 56. 
    What is the pressure in pounds per square foot on the bottom of a tank when the water depth is 16 feet?
    • A. 

      624 lbs/sq ft

    • B. 

      749 lbs/sq ft

    • C. 

      998 lbs/sq ft

    • D. 

      1,122 lbs/sq ft

    • E. 

      1,248 lbs/sq ft

  • 57. 
    What is the upward force in pounds on the bottom of an  empty sedimentation basin caused by a groundwater depth of 8 feet above the tank bottom? The basin is 10 feet wide and 30 feet long.
    • A. 

      112,300 lbs

    • B. 

      122,000 lbs

    • C. 

      131,000 lbs

    • D. 

      149,800 lbs

    • E. 

      168,500 lbs

  • 58. 
    • A. 

      1.9 GPM/sq ft

    • B. 

      2.1 GPM/sq ft

    • C. 

      2.3 GPM/sq ft

    • D. 

      2.5 GPM/sq ft

    • E. 

      2.7 GPM/sq ft

  • 59. 
    • A. 

      1.11%

    • B. 

      1.22%

    • C. 

      1.30%

    • D. 

      1.39%

    • E. 

      1.56%

  • 60. 
    • A. 

      5,000 gal/sq ft

    • B. 

      5,600 gal/sq ft

    • C. 

      6,000 gal/sq ft

    • D. 

      6,200 gal/sq ft

    • E. 

      6,400 gal/sq ft