Water treatment process

Question 1

Screening

Answer 1

The raw water is first screened to remove large debris like branches, leaves and other large particles.

Question 2

Pre-chlorination

Answer 2

This involves the addition of a small amount of chlorine to disinfect the water of bacteria and viruses.

Question 3

Coagulation/Flocculation

Answer 3

Coagulation involves the addition of certain chemicals like alum or ferric chloride to the water. This helps to bind together fine particles and colloids to form larger particles called flocs.

Question 4

Sedimentation

Answer 4

The flocs settle at the bottom of the sedimentation tank due to gravity.
The clear water is decanted from the top.

Question 5

Filtration

Answer 5

The clear water is then passed through a series of filters to remove any remaining particles or impurities.

Question 6

Disinfection

Answer 6

This involves the addition of chlorine or other disinfectants to remove any remaining bacteria or viruses in the water.

Question 7

pH adjustment

Answer 7

The pH of the water is adjusted to a suitable level using lime or other chemicals

Question 8

Fluoridation

Answer 8

Fluorine is added to the water to prevent tooth decay.

Question 9

Storage

Answer 9

The treated water is then stored in a clear water tank before being distributed to consumers.

Question 10

Distribution

Answer 10

The treated water is distributed through a network of pipes to homes, businesses and other users.