COMPARISON OF INACTIVATION OF POLIOVIRUS IN WATER BY OZONE, CHLORINE AND CHLORINE DIOXIDE

Poliovirus I in the simulated water made up of distilled water and fulvic acid was disinfected by desired concentrations of various disinfectants. Aliquots of water volume were withdrawn at 1, 3, 10 and 30 minutes and quantified with a plaque assay. When COD concentration was 20 mg/L and initial virus n (PFU)≈1×10 5 mL -1 in water, the exposure of poliovirus particles to 16.0 mg/L of chlorine, 8.0 mg/L of chlorine dioxide, and a combination of equal doses of 5.0 mg/L chlorine and 5.0 mg/L chlorine dioxide for 30 minutes respectively and to 1.22 mg/L of ozone for 10 minutes could result in complete inactivation of these viruses. The values of ρ × t for 99.99 percent inactivation of poliovirus by the above mentioned disinfectants were 662.5, 129.5, 200.0 and 3.2 mg/L min, respectively. Four disinfectants had the following order of inactivation of the virus: O 3ClO 2Cl+ClO 2Cl. On the basis of ρ × t values, single chlorine was less effective than the combination of chlorine and chlorine dioxide by factor of about 3.3 fold for poliovirus, indicating that the combined disinfectant which could also reduce by products formation was superior to the single chlorine widely used in water disinfection.