Study on removal efficiency of blended coagulants on different types of wastewater

Abstract

The conventional methods of water treatment involve various water clarification processes which include coagulation, flocculation, sedimentation and disinfection. Coagulation is a critical step in water treatment because it involves removing the colloidal particles as well as pathogens that are often attached to the particles. These methods are often not suitable because of the high cost and low availability of chemical coagulants and disinfectants. Synthetic coagulants are not always available at a reasonable price and can leave undesirable residues in treated water. In the present study, the removal efficiency of Moringa oleifera and alum were compared using different types of wastewater. The efficacy of two coagulants has been tested based on some critical parameters including dosages of coagulant, pH, EC, TDS, hardness, DO and COD of turbid water and change in values of these parameters in finished water. These coagulants obviously possessed positive coagulation abilities. There are about nine treatments with one control been used for the study. From the observed results, the blended coagulant MO: (Al2(SO4)3 treatments T7(25:25) and T8(50:50) dosage ratio gives better removal efficiencies with respect to pH, EC, TDS, hardness, DO, COD, Na and K, and appears to be suitable for treatment of wastewater, when compared with other dosages.