WATER TREATMENT OIT TEST QUESTIONS WITH 100%
ACCURATE SOLUTIONS
1) Trihalomethanes are produced when chlorine reacts with:
a) inorganic materials
b) chlorine dioxide
c) organic materials
d) ultra violet light -- Correct Answer ✔✔ c) organic materials
2) What is the chlorine residual in water?
a) the amount of chlorine applied to the water daily
b) low concentrations of chlorine gas
c) chlorine salt which is left after water evaporates
d) amount of chlorine that remains in water after disinfection -- Correct
Answer ✔✔ d) amount of chlorine that remains in water after disinfection
3) The chlorine dosage of a town's water source is 4.0 mg/L. The chlorine demand for
the water is 3.7 mg/L. What is the chlorine residual?
a) 0 mg/L
b) 0.3 mg/L
, c) 3.7 mg/L
d) 4.3 mg/L -- Correct Answer ✔✔ b) 0.3 mg/L
4) Which of the following is the correct order of processes within a cognitional surface
water treatment plant?
a) screens, coagulation, flocculation, filters, chlorination
b) screens, flocculation, coagulation, chlorination, filters
c) chlorination, screens, filtration, coagulation, flocculation
d) screens, filters, flocculation, coagulation, chlorination -- Correct Answer
✔✔ a) screens, coagulation, flocculation, filters, chlorination
5) What does the term 'contact time' mean?
a) it is the amount of time a person is exposed to chlorine
b) it is the amount of time allowed for chlorine to react in water to provide
disinfection
c) it is the amount of time a coagulant is exposed to water before flocculation
occurs
d) it is the amount of time it takes for chlorine to sterilize water -- Correct
Answer ✔✔ b) it is the amount of time allowed for chlorine to react in
water to provide disinfection
6) Backflow siphonage is caused by:
a) positive pressure in the water main
b) unprotected connections
c) unprotected openings
ACCURATE SOLUTIONS
1) Trihalomethanes are produced when chlorine reacts with:
a) inorganic materials
b) chlorine dioxide
c) organic materials
d) ultra violet light -- Correct Answer ✔✔ c) organic materials
2) What is the chlorine residual in water?
a) the amount of chlorine applied to the water daily
b) low concentrations of chlorine gas
c) chlorine salt which is left after water evaporates
d) amount of chlorine that remains in water after disinfection -- Correct
Answer ✔✔ d) amount of chlorine that remains in water after disinfection
3) The chlorine dosage of a town's water source is 4.0 mg/L. The chlorine demand for
the water is 3.7 mg/L. What is the chlorine residual?
a) 0 mg/L
b) 0.3 mg/L
, c) 3.7 mg/L
d) 4.3 mg/L -- Correct Answer ✔✔ b) 0.3 mg/L
4) Which of the following is the correct order of processes within a cognitional surface
water treatment plant?
a) screens, coagulation, flocculation, filters, chlorination
b) screens, flocculation, coagulation, chlorination, filters
c) chlorination, screens, filtration, coagulation, flocculation
d) screens, filters, flocculation, coagulation, chlorination -- Correct Answer
✔✔ a) screens, coagulation, flocculation, filters, chlorination
5) What does the term 'contact time' mean?
a) it is the amount of time a person is exposed to chlorine
b) it is the amount of time allowed for chlorine to react in water to provide
disinfection
c) it is the amount of time a coagulant is exposed to water before flocculation
occurs
d) it is the amount of time it takes for chlorine to sterilize water -- Correct
Answer ✔✔ b) it is the amount of time allowed for chlorine to react in
water to provide disinfection
6) Backflow siphonage is caused by:
a) positive pressure in the water main
b) unprotected connections
c) unprotected openings
