| ClarificationThe suspended matter can consist of large solid, settleable by gravity alone without any external aids, and non settleable material, often colloidal in nature. Steps of Clarification Coagulation Reduction of the surface charge of suspended solids and, reduction of forces of mutual repulsion results in the agglomeration of the particles. Flocculation The addition of a relatively small quantity of flocculating agent, consist of polymer of long chain containing active groups results in the agglomeration of the individual particles. Floc formation Impurities suspended and dissolved in the water can be converted to forms suitable for sedimentation, floatation or filtration by addition of appropriate additives. PrecipitationPrecipitation is effected by the additional precipitations that react with substances contained in the water to form precipitates of low solubility. | 
