Basics:
The clarification is a process used to water turbidity and suspended solids removal. For that purpose negative charge suspended particles are used to take advantage.

This process may be divided in three steps: coagulation, flocculation and sedimentation.

Coagulation is based on a coagulant addition to neutralize superficial negative charges that turbidity and suspended particles have.

Flocculation binds neutralized little particles to form bigger size particles called floc. This step occurs by chemical products addition (polymers), called flocculant.

Sedimentation consists of suspended flocks placing at the bottom. This process may be done in an usual way by gravity or in an accelerated way by displaying inclined surfaces that make suspended flocks lose energy.