Inactivation of RNA and DNA viruses in water by copper and silver ions and their synergistic effect

Mona Y M Soliman; Gertjan Medema; Boris Estrada Bonilla; Stan J J Brouns; Doris van Halem

doi:10.1016/j.wroa.2020.100077

Inactivation of RNA and DNA viruses in water by copper and silver ions and their synergistic effect

Water Res X. 2020 Nov 5:9:100077. doi: 10.1016/j.wroa.2020.100077. eCollection 2020 Dec 1.

Authors

Mona Y M Soliman¹, Gertjan Medema^{1

2}, Boris Estrada Bonilla^{3

4}, Stan J J Brouns^{3

4}, Doris van Halem¹

Affiliations

¹ Department of Water Management, Delft University of Technology, Stevinweg 1, 2628, CN Delft, the Netherlands.
² KWR Watercycle Research Institute, P.O. Box 1072, 3430 BB, Nieuwegein, the Netherlands.
³ Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629, HZ Delft, the Netherlands.
⁴ Fagenbank, Van der Maasweg 9, 2629, HZ Delft, the Netherlands.

Abstract

Cu and Ag have been used as bactericidal agents since ancient times, yet their antiviral capacity in water remains poorly understood. This study tested the effect of copper (Cu) and silver (Ag) on model RNA and DNA viruses MS2 and PhiX 174 in solution at pH 6-8. Cu caused MS2 inactivation with similar rates at pH 6 and 7 but was inert towards PhiX 174 regardless of pH. Ag inactivated both viruses, causing denaturation of MS2 and loss of capsid spikes in PhiX 174. Ag inactivation rates were pH dependent and increased with increasing pH. At pH 8, 6.5 logs of PhiX were inactivated after 3 h and 3 logs of MS2 after only 10 min. The combined use of Cu and Ag revealed synergy in disinfecting MS2 at pH ≥ 7. Although metal concentrations used were higher than the desired values for drinking water treatment, the results prove a promising potential of Cu and Ag combinations as efficient viricidal agents.

Keywords: MS2 bacteriophage; Metals; PhiX 174; Synergy; Virus; Water.