Question

Which of the following substance is added during water treatment?

• A. Baking soda
• B. Washing soda
• C. Washing powder
• D. Bleaching powder

Answer 1

The correct option is D

Bleaching powder

Water treatment follows six steps: Aeration, coagulation, clariflocculation, filtration, chlorination, and storage.

• Aeration- Oxygen is added to water.
• Coagulation- Alum is added due to which sedimentation of solid waste occurs. Then lime is added which regulates the pH by increasing it.
• Clariflocculation- Water is fed into filters.
• Filtration- Impurities are filtered out.
• Chlorination- Water is sterilised by adding chlorine tablets or bleaching powder.
• Storage- Purified water is stored.

Hence bleaching powder is the correct answer as it is added at the chlorination stage.