Coagulation and Flocculation

Abstract Coagulants and flocculants are commonly used in the destabilization and aggregation of suspended solids during water and wastewater treatment. Both inorganic salts and organic polymers may be used as coagulants, and various synthetic and natural organic polymers are applied as flocculants. Organic matter is quite well removed during coagulation, although it often requires a higher coagulant dosage. Other factors that influence the effectiveness of coagulants and flocculants are pH, temperature, mixing conditions and other ions present in the water. In order to maximize efficiency of contaminant removal while minimizing residuals, careful coagulant or flocculant dose selection and control are essential.