Water Treatment Class 3

110 Questions | Total Attempts: 5463

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Water Treatment Class 3 - Quiz

Water treatment refers to any process that makes water more suitable for a specific use – i. E. Drinking, irrigation, bathing, recreation, river flow maintenance and a host of other uses. What do you know about water treatment?


Questions and Answers
  • 1. 
    The filter rate and backwash rate of each filter shall be determined and recordedonce each
    • A. 

      Week

    • B. 

      Month

    • C. 

      Quarter

    • D. 

      Year

  • 2. 
    The culture media used in the presumptive test is of
    • A. 

      Agar

    • B. 

      A brilliant green lactose bile broth

    • C. 

      A lactose or lauryl tryptose broth

    • D. 

      A nutrient agar

  • 3. 
    Fish eyes are
    • A. 

      Undissolved clumps in solution

    • B. 

      The primary cause of floc carryover

    • C. 

      Spots of coagulant attaching to the sides of the basin.

    • D. 

      An unavoidable operating problem associated with solution tanks

  • 4. 
    Water may be aerated by several methods, almost all of which involve
    • A. 

      Covering the storage facilities

    • B. 

      Exposing a large surface area to the atmosphere

    • C. 

      Increasing the pressure

    • D. 

      Reducing its temperature

  • 5. 
    All chlorine cylinders are required to contain at least one fusible metal safety device (plug) designed to melt at between _____ Degrees F
    • A. 

      98 - 105

    • B. 

      120 - 150

    • C. 

      158 - 165

    • D. 

      200 - 212

  • 6. 
    What is the amount of chlorine required to treat 5 mil gal of water to provide a 0.8ppm residual and satisfy 2.4 ppm chlorine demand?
    • A. 

      33.33 lb

    • B. 

      66.67 lb

    • C. 

      100.00 lb

    • D. 

      133.33 lb

  • 7. 
    The detention time usually required in a conventional straight-flow sedimentationbasin is _______ h.
    • A. 

      0.5 - 1

    • B. 

      2 - 6

    • C. 

      10 - 12

    • D. 

      24

  • 8. 
    Air binding is a condition that may occur as a result of
    • A. 

      Filter-bed compaction

    • B. 

      Gravel displacement

    • C. 

      Negative head.

    • D. 

      Reaching terminal head loss.

  • 9. 
    A program for the control of algae should be instituted
    • A. 

      On a routine, periodic schedule, but not to exceed two applications per year

    • B. 

      On a seasonal basis

    • C. 

      After trend information has been established and adequate monitoring is practiced.

    • D. 

      During extended periods of warm water temperatures

  • 10. 
    With the coming of winter, the water temperature drops. A likely operational problem at a filtration plant with coagulation is
    • A. 

      Floc carryover from the sedimentation system

    • B. 

      High alkalinity

    • C. 

      High chlorine residual

    • D. 

      Odor.

  • 11. 
    A fluoride saturator
    • A. 

      Can only be used by large treatment facilities

    • B. 

      Eliminates the need for a metering pump

    • C. 

      Eliminates the need for chemical handling.

    • D. 

      Is suitable for small water systems

  • 12. 
    The most desirable place to feed activated carbon in a lime-soda ash softening plant is
    • A. 

      After lime feed.

    • B. 

      In the clearwell

    • C. 

      To raw water at earliest stage possible.

    • D. 

      With lime feed

  • 13. 
    Activated alumina is used effectively for the removal of
    • A. 

      Certain inorganic elements

    • B. 

      Herbicides and pesticides

    • C. 

      Humic substances

    • D. 

      Oxidized precipitates

  • 14. 
    Four milligrams per litre of chlorine is added continuously to a water flow thataverages 5 mgd. How much chlorine will be used in 30 days?
    • A. 

      1500 lb

    • B. 

      3000 lb

    • C. 

      5000 lb

    • D. 

      15,000 lb

  • 15. 
    Harvesting, dewatering, dredging, shading, and lining are all methods for controlling rooted aquatic plants
    • A. 

      Without much effort

    • B. 

      Physically

    • C. 

      Chemically.

    • D. 

      Biologically

  • 16. 
    Sodium hydroxide (NaOH) is often used as the base in acid-base titrations. It has a molecular weight of 40 (23 + 16 + 1 = 40). How many grams of NaOH are in 1 L of a 1N (normal) solution?
    • A. 

      20

    • B. 

      40

    • C. 

      60

    • D. 

      80

  • 17. 
    When using the multiple-tube fermentation test method and coliform organismsoccur in six out of ten of the 10-mL portions of a single standard sample, then
    • A. 

      Customers should be told to boil their water

    • B. 

      The system must collect a set of repeat samples within 24 h.

    • C. 

      The chlorine residual should be increased to 1.0 mg/L

    • D. 

      The water main should be flushed for 24 h.

  • 18. 
    Fire fighting may cause low pressure in an area of a distribution system. The lowpressure might lead to
    • A. 

      Contamination of the system by backsiphonage

    • B. 

      Ice formation in the pipes

    • C. 

      Loss of chlorine residual

    • D. 

      Muddy water.

  • 19. 
    Pinpoint floc is a condition associated with
    • A. 

      Flash mixing

    • B. 

      Low turbidity

    • C. 

      The type of chemical selected.

    • D. 

      Water temperature

  • 20. 
    Sedimentation can be improved by
    • A. 

      Lowering the water temperature after flocculation.

    • B. 

      Maintaining a uniform, horizontal, low-velocity flow across the basin

    • C. 

      Maintaining a uniform sludge blanket

    • D. 

      Reducing the detention time

  • 21. 
    A carbon dosage of 20 mg/L is required for the removal of taste and odors. With aflow of 5560 gpm, how many pounds of carbon should be fed per hour?
    • A. 

      27.8 lb

    • B. 

      49.9 lb

    • C. 

      55.6 lb

    • D. 

      668.0 lb

  • 22. 
    If a filter has been out of service and allowed to go dry, which filter control valveshould be used to refill it with water?
    • A. 

      Effluent valve

    • B. 

      Influent valve

    • C. 

      Rewash valve

    • D. 

      Backwash inlet valve

  • 23. 
    A liquid has a specific gravity of 1.16. How much would 300 gal of this liquid weight?
    • A. 

      158

    • B. 

      348

    • C. 

      2502

    • D. 

      2899

  • 24. 
    Polyelectrolytes are
    • A. 

      Coagulants

    • B. 

      Coagulant aids.

    • C. 

      Used for hardness reduction

    • D. 

      Used for pH adjustment

  • 25. 
    A tank 6 ft in overall length and 18 in. in diameter is in the shape of a cylinder withtwo hemispherical ends. Its capacity is ______ gal.
    • A. 

      7.7

    • B. 

      72.7

    • C. 

      270

    • D. 

      17.20

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