INACTIVATION OF POLIOVIRUS WITH CHLORINE DIOXIDE

The inactivation rate of poliovirus (Lsc, 2ab strain) suspended in a c ell maintenance medium (MEM) and in phosphate buffer salt solution (PB S) with chlorine dioxide (CLO2), and chlorite ion (ClO2-), of 0.4, 1.0 and 2.0 mg/l as available chlorine were studied at pH 7 and 20-degree s-C. The residual ClO2 and ClO2- formed in the test solution were dete rmined. The decrease of residual ClO2 and the formation of ClO2- in ME M virus suspension were greater than those in PBS virus suspension. In the lower concentration of CLO2 (0.4 mg/l), the decrease of ClO2 in M EM virus suspension resulted in a slower inactivation. With 2.0 mg/l o f ClO2, 99% of the virus was inactivated in about 2 min in both virus suspensions. Chlorite ion (2.0 mg/l) had little effect on the inactiva tion of the virus in 15 min contact. the inactivation rate with 2.0 mg /l of ClO2 was almost the same with that with 0.4 mg/l of HOCl reporte d in a previous paper. The similar inactivation efficiency may be due to almost the same redox potentials (E0(V)) of ClO2 and HOCl, and due to the equal oxidizing capacities of 2.0 mg/l of ClO2 and 0.4 mg/l of HOCl in the test solution in the neutral pH range.