Water Treatment MCQ – Environmental Engineering

21. Treatment required for raw water containing only carbon dioxide and odorous gases is

  1. Plain sedimentation and chlorination
  2. Chlorination only
  3. Aeration followed by disinfection
  4. Softening and chlorination
Answer
Answer. c

22. The dose of copper sulphate in water treatment varies from

  1. 0.3 p.p.m. to 0.6 p.p.m.
  2. 1 p.p.m. to 1.5 p.p.m.
  3. 2 p.p.m. to 2.5 p.p.m
  4. 3 p.p.m. to 4 p.p.m.
Answer
Answer. a

23. The disinfection efficiency of chlorine in water treatment

  1. is not dependent on pH value
  2. is increased by increased pH value
  3. remains constant at all pH value
  4. is reduced by increased pH value
Answer
Answer. d

24. The potable water is prepared from turbid surface water by adopting which of the following treatment sequences?

  1. Turbid surface water, coagulation, flocculation, sedimentation, filtration, disinfection, storage, and supply
  2. Turbid surface water, disinfection, flocculation, sedimentation, filtration, coagulation, storage, and supply
  3. Turbid surface water, filtration, sedimentation, disinfection, flocculation, coagulation, storage, and supply
  4. Turbid surface water, sedimentation, flocculation, coagulation, disinfection, filtration, storage, and supply
Answer
Answer. a

25. The water treatment required for water obtained from a deep tube well is

  1. Coagulation and flocculation only
  2. Filtration only
  3. Disinfection only
  4. Coagulation, flocculation and filtration
Answer
Answer. c

26. Select the correct sequence of the treatments or methods which are generally given to treat raw water supplies.

  1. Screening, sedimentation, coagulation, filtration, disinfection
  2. Screening, sedimentation, disinfection, aeration, coagulation
  3. Filtration, sedimentation, coagulation, disinfection
  4. Sedimentation, screening, disinfection, filtration, coagulation
Answer
Answer. a

27. An impounding reservoir is used in water supply system to

  1. evenly distribute water amongst the consumers
  2. maintain a uniform rate of supply to the township
  3. maintain an equitable pressure in the distribution system
  4. obtain a uniform quality of water
Answer
Answer. b

28. Coagulants, used for water treatment, function better when the raw water is

  1. acidic
  2. alkaline
  3. neutral
  4. none of the above
Answer
Answer. b

29. Methemoglobinemia is caused due to

  1. Nitrites
  2. Fluorides
  3. Nitrates
  4. Chlorides
Answer
Answer. c

30. The treatment of water with only chlorine is known as

  1. de-chlorination
  2. pre chlorination
  3. post chlorination
  4. plain chlorination
Answer
Answer. d