Microbiological disinfection of water and air by photocatalysis

Abstract

This article is aimed at presenting (<i>i</i>) a fundamental research on the efficiency of photocatalysis in water disinfection and (<i>ii</i>) the efficiency of a photocatalytic prototype, developed by Buxair firm, to remove avian influenza virus in air. In water disinfection, two model strains of <i>Escherichia coli</i> (K12 PHL849 and K12 PHL1273) were selected and a comparison of the efficiencies of TiO₂ Degussa P-25 <i>versus</i> TiO₂ Millennium PC500 were estimated. A more important inactivation of <i>E. coli</i> PHL1273 was obtained on TiO₂ Millennium PC500, in line with its better adherence on this solid. An experimental study was performed using a dialysis membrane to investigate the impact of the contact between the microorganisms and the photocatalyst and to determine the role of H₂O₂ generated <i>in situ</i>. In air disinfection, a total inactivation of virus A/H5N2, close to avian influenza virus A/H5N2, was obtained in a single pass in the Buxair^® gas phase dynamic photoreactor using a contaminated air flow rate of 40 m³/h.