Ozone and cavitation for water disinfection

Abstract

Ozone is a powerful oxidant, which is used extensively for water disinfection. Although it is claimed to produce less toxic byproducts than chlorine, the mutagenicity of the aldehydes and other compounds produced as byproducts during ozonation cannot be ruled out. Due to this there is a need for additional disinfection processes, which can reduce or eliminate these toxic byproducts by reducing the usage of ozone. Moreover, higher cost of these biocides necessitates its optimum usage. Synergistic processes reduces to half or one-third the required concentration of ozone for disinfection as found in this study. Due to these factors, synergistic processes appear to be promising for water disinfection. In this study, we investigate the viability of ozonation and cavitation (hydrodynamic cavitation and ultrasonication) for the disinfection of the heterotropic plate count (HPC) bacteria and indicator microorganisms (total coliforms, faecal coliforms and faecal streptococci) in bore well water.