Competence of blended coagulants for surface water treatment

Owing to the advantages of the natural coagulants under study, the present objective is to study the efficiency of blended coagulants: alum and chitin; alum and sago; and alum + chitin + sago. In this attempt, we have reduced the quantity of alum dose and added increasing quantities of the natural coagulants. The surface water samples collected from nearby sources were analyzed for the following parameters pre- and post-treatment with the coagulants. Coagulation and flocculation experiments were carried out using conventional jar test apparatus. Turbidity removal was observed to be nearly 99.29% at all pH ranges and doses. Removal of conductivity, solids and hardness was 58.83%, 32.03% and 33.33%, respectively. From the results obtained, it can be observed that the efficiency of blended coagulants in removal of various physicochemical parameters from the waters was better when compared to individual coagulants. The floc size in blend coagulants was larger than that of single coagulants. The data obtained in this study indicated the coagulation efficiency could be enhanced by using the blend coagulant.