Which of the following is a chemical treatment process in context to water treatment?

Coagulation is a chemical treatment step, as it adds chemicals that make fine particles clump together.

Sedimentation is a physical step where particles settle by gravity.

Filtration is a physical step that strains particles through a bed of media.

A grit chamber is a physical unit that settles out sand and grit.

Coagulants like alum neutralise particle charges so they bind into larger flocs.

These flocs then settle and are removed, clearing turbid water.