An established leader in Water & Wastewater treatment

Ozone disinfection

Ozone is a very powerful disinfectant. Table 1 compares Ct-values (concentration * time) of various disinfectants for the deactivation of viruses.
Allthough chlorine is very suitable for the deactivation of bacteria and viruses, it cannot be used to deactivate protozoa.
Table 2 shows the disinfection rate for the Giardia cyst. In this table you can see that chlorine and chloramines have lower Ct-values. This means that ozone is a more powerful disinfectant to deactivate this microorganism.
The protozoa Cryptosporidium is hardly deactivated by chlorine and chloramines [30,31]. The Ct-value for deactivation by chlorine varies between 3000 and 4000 mg min/L for 1-log deactivation (= 90% deactivation). Both tables are derived from the Enviromental Protection Agency (EPA) [30].