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WATER TREATMENT OPERATOR LEVEL 1
CERTIFICATION STUDY GUIDE EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS | ALREADY A
GRADED
What has little effect on colloidal particles because of their small size? -
ANSWER- Gravity
What natural electrical force keeps colloidal particles apart in water
treatment? - ANSWER- Zeta potential
What does the zeta potential measure? - ANSWER- The number of
excess electrons found on the surface of all particulate matter
What device collects the settled water as it leaves the sedimentation
basin? - ANSWER- The effluent launder
In solid-contact basins with fairly constant water quality parameters,
how often should the solids concentration be determined? - ANSWER-
At least twice per day
What is the definition of decant? - ANSWER- To draw off the liquid
from a vessel of any size without stirring up bottom sedimentation
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How often should sedimentation basins with mechanical sludge removal
equipment be drained and inspected? - ANSWER- Once a year
What is the most important reason to reduce turbidity? - ANSWER- To
remove pathogens
What is the filtration flow rate through a manganese greensand pressure
filter at 10 degrees C? - ANSWER- 2 to 3 gpm/sq ft
When is a filter ripening? - ANSWER- When it becomes more efficient
in particle removal
Virgin greensand can be regenerated by soaking the filter bed for several
hours in a chlorine solution of what? - ANSWER- 100 mg/L
What precipitates can foul a cation exchange resin? - ANSWER- Iron
and manganese
What process works best for sequestering manganese? - ANSWER-
Polyphosphates and chlorine
Adding CO2 to water is known as what? - ANSWER- Recarbonation
What must be done in the ion-exchange softening process once the resin
can no longer soften water? - ANSWER- Regeneration
WATER TREATMENT OPERATOR LEVEL 1
CERTIFICATION STUDY GUIDE EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS | ALREADY A
GRADED
What has little effect on colloidal particles because of their small size? -
ANSWER- Gravity
What natural electrical force keeps colloidal particles apart in water
treatment? - ANSWER- Zeta potential
What does the zeta potential measure? - ANSWER- The number of
excess electrons found on the surface of all particulate matter
What device collects the settled water as it leaves the sedimentation
basin? - ANSWER- The effluent launder
In solid-contact basins with fairly constant water quality parameters,
how often should the solids concentration be determined? - ANSWER-
At least twice per day
What is the definition of decant? - ANSWER- To draw off the liquid
from a vessel of any size without stirring up bottom sedimentation
, 2|Page
How often should sedimentation basins with mechanical sludge removal
equipment be drained and inspected? - ANSWER- Once a year
What is the most important reason to reduce turbidity? - ANSWER- To
remove pathogens
What is the filtration flow rate through a manganese greensand pressure
filter at 10 degrees C? - ANSWER- 2 to 3 gpm/sq ft
When is a filter ripening? - ANSWER- When it becomes more efficient
in particle removal
Virgin greensand can be regenerated by soaking the filter bed for several
hours in a chlorine solution of what? - ANSWER- 100 mg/L
What precipitates can foul a cation exchange resin? - ANSWER- Iron
and manganese
What process works best for sequestering manganese? - ANSWER-
Polyphosphates and chlorine
Adding CO2 to water is known as what? - ANSWER- Recarbonation
What must be done in the ion-exchange softening process once the resin
can no longer soften water? - ANSWER- Regeneration
