Question

36. Arrange the process in sequence for the purification of drinking water

(1) lime feeder, alum feeder

(2) filtration

(3) mechanical mixing

(4) chlorination

• A. 1324
• B. 1243
• C. 2345
• D. 2341

Answer 1

The correct option is A

1324

1. Lime feeder, alum feeder: In this process, lime and alum are added to the water chamber.
2. Mechanical mixing: Alum and lime are stirred using massive mechanical blades. This water is then poured into a sedimentation tank where the processes of suspended impurities are accelerated by alum. Some bacteria are caught and eliminated during this precipitation process.
3. Filtration: The resulting pure water is then pumped through a sand and gravel filter to get rid of any leftover contaminants in the suspension.
4. Chlorination: The addition of bleaching powder produces chlorine, which kills harmful bacteria, and results in pure water that is stored in storage tanks.

The water obtained at the end of the purification process is free from suspended impurities and harmful bacteria.

Hence (A) will be the correct option.