Question

Potable water is obtained from river water by the process of

• A. Sedimentation only
• B. Sedimentation and filtration only
• C. Sedimentation, filtration and chlorination only
• D. None of these

Answer 1

The correct option is C

Sedimentation, filtration and chlorination only

The explanation for the correct option:

(c)Sedimentation, filtration, and chlorination only:

• The potable water is obtained from all the above processes.
• Sedimentation: River water is pumped into a series of large settling tanks and allowed to stay still for a day when very heavy particles of clay, etc. settle at the bottom of the settling tank.
• Filtration through sand and gravel: The clear water is pumped into a sand and gravel filter which completely removes suspended impurities.
• Chlorination of water: The clear water is chlorinated to remove any harmful bacteria present in it. it is then collected in storage tanks. from where it is distributed.

The explanation for the incorrect option:

(a)Sedimentation only:

• Only sedimentation of water is not possible to filter water.

(b)Sedimentation and filtration only:

• sedimentation and filtration, as well as chlorination, are required to potable water which is fit for drinking.

Therefore, Option (c) i.e Sedimentation, filtration, and chlorination only is the correct answer.