Water Operator NC B Certification Exam with verified answers.

Water Operator NC B Certification Exam
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with verified answers
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Presedimentation |- |CORRECT |ANSWER✔✔-Reduce |silt |in |water

Settling |zone |- |CORRECT |ANSWER✔✔-Calm |area |in |settling |basin |where |suspended |materials |settle

Coagulation |- |CORRECT |ANSWER✔✔-Occurs |in |Seconds

Flocculation |- |CORRECT |ANSWER✔✔-Occurs |in |Minutes |(optimum |velocity |0.5 |fps)
Floc |should |be |popcorn |sized

Sedimentation |- |CORRECT |ANSWER✔✔-Occurs |in |Hours |(4 |hour |detention |time)

Typical |Coagulants |- |CORRECT |ANSWER✔✔-Aluminum |Sulfate |Al2(SO4)3
Ferrix |Fe2(SO4)3

pH |Increasing |Chemicals |- |CORRECT |ANSWER✔✔-Lime |(Ca(OH)2), |Caustic |soda, |Soda |ash, |
Bicarbonate

pH |Lowering |- |CORRECT |ANSWER✔✔-Carbon |dioxide

Jar |tests |- |CORRECT |ANSWER✔✔-Establish |optimum |coagulant |dosage

MCL/SMCL |Fluoride |- |CORRECT |ANSWER✔✔-4 |ppm/2 |ppm

Fluoridation |chemicals |- |CORRECT |ANSWER✔✔-Sodium |fluoride, |sodium |silicofluoride, |
hydrofluosilicic |acid

Fluoride |saturators |- |CORRECT |ANSWER✔✔-Volumetric |(sclew |or |roll |type), |gravimetric |(belt-
type), |saturator, |upflow, |and |downflow

Saturator |- |CORRECT |ANSWER✔✔-75 |mg/L |of |hardness |and |above, |softened |water |required

Sodium |Fluoride |(NaF) |- |CORRECT |ANSWER✔✔-Powder, |higher |solubility |with |higher |
temperature
Purity: |0.98
AFI: |0.452

Sodium |Silicofluoride |(Na2SiF6) |- |CORRECT |ANSWER✔✔-Powder, |higher |solubility |with |higher |
temperature
Purity: |0.985
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, AFI: |0.606

Hydrofluosilicic |acid |(H2SiF6) |- |CORRECT |ANSWER✔✔-Infinite |at |all |temperatures, |23% |acid |= |
9.938 |lbs/gal
Purity: |0.23
AFI: |0.792

Scaling |- |CORRECT |ANSWER✔✔-Can |be |caused |by |hard |water |in |systems |using |saturators

Closed-loop |feeding |- |CORRECT |ANSWER✔✔-used |for |large |hydofluosilicic |acid |sistems

What |dosage |of |fluoride |will |cause |a |minimum |degree |of |fluorosis? |- |CORRECT |ANSWER✔✔-1 |
ppm

Supernatant |- |CORRECT |ANSWER✔✔-The |liquid |that |stands |above |a |sediment |or |precipitate

System |issuing |permit |to |discharge |process |wastes |- |CORRECT |ANSWER✔✔-National |Pollutant |
Discharge |Elimination |System

Methods |of |sludge |disposal |- |CORRECT |ANSWER✔✔-Land |application, |discharge |to |sanitary |
sewers, |disposal |into |sanitary |landfills |and |lagoons

Vacuum |trucks |are |used |for |removing |sludge |because |they |- |CORRECT |ANSWER✔✔-Develop |the |
fewest |problems |with |clogging

fahrenheit |to |celsius |- |CORRECT |ANSWER✔✔-1.8*C |= |F-32

Air |binding |- |CORRECT |ANSWER✔✔-caused |by |the |reduction |of |pressure |resulting |from |operating |
under |a |negative |head

Sand |filters |- |CORRECT |ANSWER✔✔-designed |to |remove |suspended |solids

Formation |of |mud |balls |in |a |filter |can |be |overcome |by |- |CORRECT |ANSWER✔✔-changing |the |dose |
of |the |coagulant |or |coagulant |aid

All |routine |coliform |test |results |must |be |reported |to |the |state |by |which |day |of |the |following |month? |- |
CORRECT |ANSWER✔✔-10th

Coliform |bacteria |- |CORRECT |ANSWER✔✔-aerobic |and |facultative |anaerobic, |gram |negative, |non |
spore |forming, |rod-shaped |bacilli, |which |ferment |lactose |with |the |formation |of |gas |within |48 |hours |at |
35 |degrees

BGB |- |CORRECT |ANSWER✔✔-media |used |in |the |confirmed |test |for |total |coliform |bacteria

Violations |for |microbiological |MCLs |must |be |reported |to |the |state |by |- |CORRECT |ANSWER✔✔-end
|of |the |next |business |day

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