A Comparative Study of Bacteria and Virus Removal by the Coagulation Process

Contamination of water sources used for consumption especially, with pathogenic virus raises concern among consumer, and use of Escherichia coli or E. coli as an indicator for assessing the performance of pathogenic virus removal in water treatment process may not be reliable due to characteristic differences. Thus, an indicator that is similar to pathogenic viruses may be more suitable. In this study, bacteriophage MS– 2 and E. coli IFO3301 were used to investigate removal efficiencies of the coagulation process as viral and bacterial indicator, respectively with poly aluminum chloride, alum and ferric chloride at pH 5 7 and 9. It revealed that removal efficiencies of both bacteriophage MS–2 and E. coli increased when higher coagulant concentration, and highest at 50 mg/L with poly aluminum chloride followed by alum and ferric chloride, respectively. Additionally, pH value also affected removal efficiencies in which the highest removal efficiency was achieved at 5. Reduction of Bacteriophage MS–2 in the coagulation process was higher than E. coli at all pH and concentration of the three coagulants. Based on the results, it can conclude that virus and bacteria removal efficiencies in the coagulation process are difference and the use of bacteriophage MS–2 can accurately estimate virus removal efficiency in the coagulation process than the conventional indicator, E. coli.