Question

Arrange the following process in order with context to water purification:

a- Disinfection

b- Filtration

c- Coagulation

d- Sedimentation

e- Flocculation

1. c, e, d, b, a
2. e, c, d, b, a
3. a, b, c, d, e
4. c, e, b, d, a

Answer 1

Correct Answer - Option 1 : c, e, d, b, a

Concepts:

The correct sequence is :

Coagulation, Flocculation, Sedimentation, Filtration, Disinfection

Coagulation is the destabilization of colloids by addition of chemicals that neutralize the negative charges by rapid mixing. The chemicals are known as coagulants; usually have higher valence cationic salts (Al³⁺, Fe³⁺ etc.). Coagulation is a chemical process.

Flocculation is the agglomeration of destabilized particles into large size particles known as floc by slow mixing which can be effectively removed by sedimentation or flotation.

Filtration is done to remove the remaining inorganic particles which cannot be removed by coagulation aided sedimentation and after that disinfection is done by addition of Chlorine to kill pathogens.