INACTIVATION OF MICROORGANISMS ON THE PHOTOCATALYTIC SURFACES IN AIR
Resource
AEROSOL SCIENCE AND TECHNOLOGY v.37 n.12 pp.939-946
Journal
AEROSOL SCIENCE AND TECHNOLOGY
Journal Volume
v.37
Journal Issue
n.12
Pages
939-946
Date Issued
2003
Date
2003
Author(s)
LIN, YI-CHANG
LI, CHIH-SHAN
Abstract
Photocatalysis by TiO2 is a new technology that can generate strong oxidant radicals to react with organic pollutants and sterilize water. In this research, the disinfections of two microorganisms such as Bacillus subtilis (B. subtilis ) and Penicillium citrinum (P. citrinum ) were investigated. The commercial TiO2 filter and immobilized TiO2 slide were used as photocatalytic surfaces . The light intensity levels included 240, 740, 1400, and 2100 muW/cm(2). Our results indicated that higher black light intensity resulted in higher microorganism inactivation rates. It was demonstrated that not only photocatalysis but also photolysis had germicidal effects on P. citrinum in both kinds of surface matrixes. For B. subtilis, photolysis was more significant than photocatalysis. In addition, microorganism inactivation rates of the TiO2 filter were found to be smaller than those of the TiO2 slide for both B. subtilis and P. citrinum . At a light intensity of 740 muW/cm(2), the calculated 50% survival inactivation time of the TiO2 filter for B. subtilis and P. citrinum were 0.99 h and 2.55 h, respectively. The calculated 50% survival inactivation time of the TiO2 slide for B. subtilis and P. citrinum were 0.61 h and 1.64 h, respectively. Furthermore, the inactivation rate of P. citrinum was smaller than B. subtilis on both filter and slide. This might be related to the fact that P. citrinum was more resistant than B. subtilis.
Subjects
POWDERED SEMICONDUCTOR TIO2
HETEROGENEOUS PHOTOCATALYSIS
SAMPLING PERFORMANCE
ESCHERICHIA-COLI
FUNGAL SPORES
Type
journal article