WATER TREATMENT OPERATOR LEVEL 1 SAMPLE QUESTIONS (WATER OPERATOR CERTIFICATION STUDY GUIDE) CORRECT ANSWERS

WATER TREATMENT OPERATOR
LEVEL 1 SAMPLE QUESTIONS
(WATER OPERATOR CERTIFICATION
STUDY GUIDE) CORRECT ANSWERS

What are the two important factors impacting the effectiveness of chlorination? - ans-
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Concentration of chlorine and contact time ws ws ws ws ws



The treatment process that controls corrosion or scaling is known as what? - ans-
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Stabilization
Permanganate reactions are highly dependent on what factor? - ans-pH ws ws ws ws ws ws ws ws wsws



It is hardest to kill the organism that causes what illness? - ans-Cryptosporidiosis
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Disinfection of water wells with free chlorine requires exposure for how long and at wha
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t concentration? - ans-12 to 24 hours; 50mg/L
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Flocculation basins are usually designed to provide for detention times of how long? -
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ans-15 to 45 minutes
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Alum works best in a pH range of what? - ans-5.8 to 7.5
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What has little effect on colloidal particles because of their small size? - ans-Gravity
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What natural electrical force keeps colloidal particles apart in water treatment? - ans-
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Zeta potential ws



What does the zeta potential measure? - ans-
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The number of excess electrons found on the surface of all particulate matter
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What device collects the settled water as it leaves the sedimentation basin? - ans-
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The effluent launder
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In solid-
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contact basins with fairly constant water quality parameters, how often should the solid
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s concentration be determined? - ans-At least twice per day
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What is the definition of decant? - ans-
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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
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drained and inspected? - ans-Once a year
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What is the most important reason to reduce turbidity? - ans-To remove pathogens
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What is the filtration flow rate through a manganese greensand pressure filter at 10 de
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grees C? - ans-2 to 3 gpm/sq ft
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When is a filter ripening? - ans-When it becomes more efficient in particle removal
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Virgin greensand can be regenerated by soaking the filter bed for several hours in a chl
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orine solution of what? - ans-100 mg/L
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What precipitates can foul a cation exchange resin? - ans-Iron and manganese
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What process works best for sequestering manganese? - ans-
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Polyphosphates and chlorine ws ws



Adding CO2 to water is known as what? - ans-Recarbonation
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