Microbial inactivation associated with ozone treatment depends on several environmental factors. Temperature affects the solubility, stability and reactivity of ozone. Relative humidity, pH, the presence of certain additives, contact time, type of organism, dosage, turbidity, the presence of organic material and demand for ozone all affect its activity and efficiency (Roy et al. 1982; Fisher et al. 2000; Voidarou et al. 2007). It is therefore necessary to precisely determine the required dosage in each case