Publication Abstract

Disinfection of feline calicivirus (a surrogate for Norovirus) in wastewaters

J.A. Tree, M.R. Adams and D.N. Lees

To compare the inactivation of feline calicivirus (FCV) (a surrogate for Norovirus, NV) with the reduction of a bacterial water quality indicator (Escherichia coli), a human enteric virus (poliovirus) and a viral indicator (MS2, FRNA bacteriophage), following the disinfection of wastewaters.

Bench-scale disinfection experiments used wastewater (sterilized by gamma-irradiation) seeded with laboratory-cultured organisms. Seeded primary effluent was treated with different doses of applied free chlorine (8, 16 and 30 mg l^-1). FCV and E. coli were easily inactivated by >4 log₁₀, within 5 min with a dose of 30 mg l^-1 of applied chlorine. Poliovirus was more resistant and a reduction of 2·85 log₁₀ was seen after 30 min, MS2 was the most resistant organism (1 log₁₀ inactivation). In further experiments seeded secondary effluent was treated with different doses of u.v. irradiation. To achieve a 4-log₁₀ reduction of E. coli, FCV, poliovirus and MS2 doses of 5·32, 19·04, 27·51 and 62·50 mW s cm^-2, respectively, were required.

Feline calicivirus and E. coli seeded in primary wastewater were very susceptible to chlorination compared with poliovirus and MS2. In contrast, FCV seeded in secondary wastewater was more resistant to u.v. irradiation than E. coli but more sensitive than poliovirus and MS2. Significance and Impact of the

FRNA phage was more resistant to inactivation than all the viruses tested. This suggests FRNA phage would be a useful and conservative indicator of virus inactivation following disinfection of wastewaters with chlorination or u.v. irradiation.

Reference:

J.A. Tree, M.R. Adams and D.N. Lees (2005). Disinfection of feline calicivirus (a surrogate for Norovirus) in wastewaters. Journal of Applied Microbiology, 98(1): 155-162