In which process does coagulation typically occur?

Coagulation is the process in water treatment where destabilized particles in the water aggregate to form larger particles, known as floc. This is a critical step that helps improve the efficiency of subsequent treatment processes. The correct placement of coagulation typically occurs before filtration.

Before filtration, coagulation treats the water to ensure that suspended solids and other small particulates clump together. This makes them easier to remove during filtration. By having larger particles, the filter media can more effectively capture and remove impurities, leading to clearer and cleaner water.

While sedimentation is a subsequent process where these larger flocs settle out of the water, it is not where coagulation occurs. Flocculation follows coagulation and involves gentle mixing to encourage further particle aggregation. Softening, which is primarily aimed at reducing hardness in water, is also a separate stage that does not involve coagulation directly. Understanding the sequence of these processes is crucial for effective water treatment.