CA Water Treatment Plant Operator Quiz Chapter 5

40 Questions | Total Attempts: 2335

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CA Water Treatment Plant Operator Quiz Chapter 5

Sedimentation 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. 
    Smooth circular particles will settle slower than irregular particles with ragged edges.
    • A. 

      True

    • B. 

      False

  • 2. 
    The settling rate (settling velocity) of a particle becomes much slower as the temperature increases.
    • A. 

      True

    • B. 

      False

  • 3. 
    High winds can have an adverse effect on tube settlers.
    • A. 

      True

    • B. 

      False

  • 4. 
    Whenever actual flows in a water treatment plant approach or exceed design flows, problems are likely to develop.
    • A. 

      True

    • B. 

      False

  • 5. 
    Operators often have trouble visualizing what is happening in an upflow clarifier and become discouraged or upset when routine problems associated with solids-contact units occur.
    • A. 

      True

    • B. 

      False

  • 6. 
    In solids-contact units, a rising flow rate will increase the depth of the slurry and also increase its volume or density.
    • A. 

      True

    • B. 

      False

  • 7. 
    When operating a solids-contact clarification unit, the set of recirculation speeds for warm-weather operation is the same as those used during cold weather.
    • A. 

      True

    • B. 

      False

  • 8. 
    Accumulated sludge in the sedimentation basin bottom or sludge sump is periodically removed for further processing (dewatering) and ultimate disposal.
    • A. 

      True

    • B. 

      False

  • 9. 
    Changes in raw water quality may be considered a normal condition for many plants and an abnormal condition for other water treatment plants.
    • A. 

      True

    • B. 

      False

  • 10. 
    Significant changes in source water turbidity levels, either increases or decreases, require that operators verify the effectiveness of the sedimentation process n removing suspended solids and floc.
    • A. 

      True

    • B. 

      False

  • 11. 
    Results of lab tests are valuable, even if not used.
    • A. 

      True

    • B. 

      False

  • 12. 
    The metallic parts of clarifiers and solids-contact units must be protected from corrosion.
    • A. 

      True

    • B. 

      False

  • 13. 
    • A. 

      To remove grease and reduce the load on the backwashing process

    • B. 

      To remove iron and manganese and to reduce the load on the sludge handling facilities

    • C. 

      To remove pathogens and to reduce the load on the chlorine contact basin

    • D. 

      To remove suspended solids (particles) that are denser (heavier) than water and to reduce the load on the filters

  • 14. 
    Currents in the sedimentation basin are beneficial to what extent?
    • A. 

      That they distribute suspended solids evenly throughout the basin

    • B. 

      That they increase the expected performance of the sedimentation basin

    • C. 

      That they promote flocculation

    • D. 

      That they release floatables to the surface

  • 15. 
    Why were high-rate or tube settlers developed?
    • A. 

      To eliminate the need for sludge scrapers

    • B. 

      To increase the area required for the sedimentation basin

    • C. 

      To increase the settling efficiency of the conventional rectangular sedimentation basins

    • D. 

      To reduce the effect of winds on sedimentation

  • 16. 
    What are the major means by which operators can control water treatment processes?
    • A. 

      By adjusting chemicals and chemical feed rates

    • B. 

      By adjusting influent flows

    • C. 

      By adjusting maintenance programs

    • D. 

      By adjusting water temperature

  • 17. 
    Why should solids-contact units be drained periodically?
    • A. 

      To inspect the belt drive

    • B. 

      To inspect the chemical storage facilities

    • C. 

      To inspect the sludge collectors for wear and corrosion

    • D. 

      To inspect the slurry volume

  • 18. 
    Why must operators monitor the performance of the sedimentation process?
    • A. 

      In order to anticipate quality or performance changes

    • B. 

      In order to count particulate loadings on filters

    • C. 

      In order to maintain sludge levels on the bottom of the basin

    • D. 

      In order to meet changing flow demands

  • 19. 
    The actual frequency of monitoring the sedimentation process should be based on which factors?
    • A. 

      Environmental conditions and regulatory requirements

    • B. 

      Number of operators and the condition of the training program

    • C. 

      Source of the water supply and variations in the supply

    • D. 

      Temperature of the water and weather conditions

  • 20. 
    What should the operator do when source water turbidity levels are increasing rapidly?
    • A. 

      Increase the detention time in the upstream impoundment

    • B. 

      Increase the filtration rate through the filters

    • C. 

      Locate the source and implement erosion control practices

    • D. 

      Verify the effectiveness of the coagulant chemicals and the dosage being applied at the flash mixer

  • 21. 
    • A. 

      Constant maintenance and calibration of laboratory equipment and correct lad procedures

    • B. 

      The use of different sample locations and analytical procedures

    • C. 

      Te use of regulatory personnel in collecting the samples and performing laboratory analyses

    • D. 

      Training programs and higher salaries

  • 22. 
    What are preventive maintenance (P/M) programs designed to ensure? The continued satisfactory operation of treatment plant facilities by
    • A. 

      Avoiding the need for excessive good housekeeping practices

    • B. 

      Maintaining equipment on an as-needed basis when time becomes available

    • C. 

      Purchasing equipment with fewer maintenance requirements

    • D. 

      Reducing the frequency of breakdown failures

  • 23. 
    What types of presedimentation facilities are used to reduce the solids-removal load at the water treatment plant?
    • A. 

      Booster pumps

    • B. 

      Debris dams

    • C. 

      Grit basins

    • D. 

      Impoundments

    • E. 

      Intake screens

  • 24. 
    • A. 

      Density currents cause by differences in suspended solids concentrations and temperature differences

    • B. 

      Eddy currents produced by the flow of the water coming into and leaving the basin

    • C. 

      Internal currents caused by the movement of microorganisms in the water

    • D. 

      Sludge currents caused by the flow of sludge along the bottom

    • E. 

      Surface currents caused by winds

  • 25. 
    • A. 

      Minimize density currents due to temperature differences

    • B. 

      Minimize the tendency of the water to flow at the inlet velocity straight through the basin

    • C. 

      Minimize viscosity changes

    • D. 

      Minimize volumetric flow losses

    • E. 

      Minimize wind currents

  • 26. 
    • A. 

      Basin inlet and outlet design

    • B. 

      Effective exchangeable volume (portion of basin through which the water flows)

    • C. 

      Short-circuiting

    • D. 

      Time of day the tests are performed

    • E. 

      Type of dye used in tests

  • 27. 
    What chemicals can an operator add to water to cause sufficient alkalinity to be present for coagulation?
    • A. 

      Calcium hydroxide (lime)

    • B. 

      Hydrochloric acid (muriatic acid)

    • C. 

      Sodium carbonate (soda ash)

    • D. 

      Sodium hydroxide (caustic soda)

    • E. 

      Sodium hypochlorite (hypochlorite)

  • 28. 
    When performing the jar test to optimize chemical dosages, operators should duplicate in the jar tester, as nearly as possible, which conditions that occur in the plant?
    • A. 

      Budget

    • B. 

      Chemical dosage

    • C. 

      Detention period

    • D. 

      Iron and manganese

    • E. 

      Mixing speeds

  • 29. 
    • A. 

      Chlorine residual of the water leaving the sedimentation basin

    • B. 

      Temperature of the entering water

    • C. 

      Temperature of the leaving water

    • D. 

      Turbidity of the water entering the sedimentation basin

    • E. 

      Turbidity of the water leaving the sedimentation basin

  • 30. 
    Flocs coming over the ends of the sedimentation basin are indicative of which conditions?
    • A. 

      Density currents

    • B. 

      High flows

    • C. 

      Low flows

    • D. 

      Short-circuiting

    • E. 

      Sludge blankets that are too deep

  • 31. 
    Which factors could cause changes in source wate alkalinity and pH?
    • A. 

      Decreased rates of sludge removal

    • B. 

      Increased filtration rates

    • C. 

      Spills

    • D. 

      Storms

    • E. 

      Waste discharges

  • 32. 
    • A. 

      Evaluate overall process performance

    • B. 

      Increase the frequency of process monitoring

    • C. 

      Make appropriate process changes and verify responses

    • D. 

      Perform jar tests if indicated

    • E. 

      Perform necessary analyses to determine the extent of the change

  • 33. 
    Which items should be checked after start-up and during normal operation of a sludge pump?
    • A. 

      Excessive noise

    • B. 

      Excessive vibration

    • C. 

      Leakage (water, lubricants)

    • D. 

      Overheating

    • E. 

      Suction and discharge pressures

  • 34. 
    In the normal operation of the sedimentation process, the operator will be expected to perform which routine maintenance functions as a part of an overall preventive maintenance program?
    • A. 

      Check bearing for wear, overheating, and proper lubrication

    • B. 

      Ensure good ventilation (air circulation) in equipment work areas

    • C. 

      Inspect for alignment of shafts and couplings

    • D. 

      Keep electric motors free of dirt and moisture

    • E. 

      Maintain proper lubrication and oil levels

  • 35. 
    • A. 

      1.4 hours

    • B. 

      1.6 hours

    • C. 

      1.8 hours

    • D. 

      2.0 hours

    • E. 

      2.2 hours

  • 36. 
    • A. 

      112,200 gallons

    • B. 

      123,400 gallons

    • C. 

      134,640 gallons

    • D. 

      149,600 gallons

    • E. 

      179,500 gallons

  • 37. 
    • A. 

      3,120 pounds

    • B. 

      3,780 pounds

    • C. 

      4,368 pounds

    • D. 

      4,992 pounds

    • E. 

      5,616 pounds

  • 38. 
    • A. 

      25.2 gallons

    • B. 

      28.8 gallons

    • C. 

      31.2 gallons

    • D. 

      35.9 gallons

    • E. 

      40.0 gallons

  • 39. 
    • A. 

      962 square feet

    • B. 

      1,256 square feet

    • C. 

      1,480 square feet

    • D. 

      1,590 square feet

    • E. 

      1,960 square feet

  • 40. 
    How many pounds of copper sulfate will be needed to dose a reservoir with 0.5 mg/L copper? The reservoir volume is 28 million gallons. The copper sulfate is 25 percent copper.
    • A. 

      335 pounds

    • B. 

      360 pounds

    • C. 

      400 pounds

    • D. 

      435 pounds

    • E. 

      470 pounds