Modeling phage induced bacterial disinfection rates and the resulting design implications

The phage induced disinfection rates of Escherichia coli K-12 MG1655 in the presence of coliphage Ec2 were determined under a wide range of phage and bacterial concentrations. These rates were elucidated to determine if phages could be used in water and wastewater treatment systems as a biological based disinfectant. Disinfection rates ranging from 0.13 ± 0.1 to 2.03 ± 0.1 h⁻¹ were observed for E. coli K12. A multiple linear regression model was used to explain the variance in the disinfection rates, and this model demonstrated an interaction effect between the initial phage and bacterial concentrations. Furthermore, the results were modeled with particle aggregation theory, which over predicted the disinfection rates at higher phage and bacterial concentrations, suggesting additional interactions. Finally, the observed and predicted disinfection rates were used to determine additional design parameters. The results suggested that a phage based disinfection process may be suitable for the inactivation of specific pathogens in plug flow reactors, such as the pathogens in hospital wastewater effluents and the bacteria responsible for foaming and sludge bulking in activated sludge processes.