INTEC   05402
INSTITUTO DE DESARROLLO TECNOLOGICO PARA LA INDUSTRIA QUIMICA
Unidad Ejecutora - UE
artículos
Título:
Effect of the Radiation Flux on the Photocatalytic Inactivation of Spores of Bacillus Subtilis
Autor/es:
ALFANO, O.M.; IRAZOQUI, H.A.; IMOBERDORF, G.E.
Revista:
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
Editorial:
ELSEVIER SCIENCE SA
Referencias:
Año: 2010 vol. 214 p. 171 - 180
ISSN:
1010-6030
Resumen:
In this
paper, the photocatalytic inactivation of dry spores of Bacillus subtilis
dispersed on TiO2 films and irradiated with UV-A radiation (2.440.29mWcm−2)
was studied. Experimental results indicate a minor reduction in the number of
viable spores (69% of inactivation after 48 h of irradiation) when they were irradiated
with UV-A radiation on borosilicate glass plates (without TiO2), confirming the
resistance of spores to UV-A radiation. However, the number of viable spores
significantly decreased when they were irradiated with UV-A under similar
conditions but on plates coated with TiO2 (99.88% of inactivation after 24 h of
irradiation), showing that dry spores of B. subtilis are vulnerable to
photocatalytic inactivation. A simplified scheme was proposed to model the
photocatalytic inactivation of B. subtilis, from which a kinetic expression was
derived. Since the rate of photocatalytic inactivation is strongly dependent on
the flux of the UV radiation on the TiO2 films, the radiation field was modeled
by means of CFD software. Experimental results of spore inactivation were
fitted with the derived kinetic expression, showing the inactivation rate has a
square root dependence on the radiation flux reaching the photocatalyst film.