Inactivation of Enteric Adenovirus and Feline Calicivirus by Chlorine Dioxide

Authors

Jeanette A. Thurston-Enriquez, University of Nebraska-Lincoln
Charles N. Haas, Drexel UniversityFollow
Joseph Jacangelo, Montgomery Watson Harza, Lovettsville, Virginia
Charles P. Gerba, University of ArizonaFollow

Date of this Version

6-1-2005

Comments

Published in APPLIED AND ENVIRONMENTAL MICROBIOLOGY, June 2005, p. 3100–3105.

Abstract

Chlorine dioxide (ClO₂) inactivation experiments were conducted with adenovirus type 40 (AD40) and feline calicivirus (FCV). Experiments were carried out in buffered, disinfectant demand-free water under high- and low-pH and -temperature conditions. Ct values (the concentration of ClO₂ multiplied by contact time with the virus) were calculated directly from bench-scale experiments and from application of the efficiency factor Hom (EFH) model. AD40 Ct ranges for 4-log inactivation (Ct_99.99%) at 5°C were >0.77 to 0.80 to 0.49 to Ct_99.99% ranges were observed for pH 6 and 8, respectively. FCV Ct_99.99% ranges for 5°C experiments were >20.20 to 0.68 mg/liter x min for pH 6 and 8, respectively. For 15°C FCV experiments, Ct_99.99% ranges were >4.20 to Ct values and inactivation curves demonstrated that the EFH model described bench-scale experiment data very well. Observed bench-scale Ct_99.99% ranges and EFH model Ct_99.99%values demonstrated that FCV is more resistant to ClO2 than AD40 for the conditions studied. U.S. Environmental Protection Agency guidance manual Ct_99.99% values are higher than Ct_99.99% values calculated from bench-scale experiments and from EFH model application.