Inactivation of Microorganisms on the Photocatalytic Surfaces in Air
Titel:
Inactivation of Microorganisms on the Photocatalytic Surfaces in Air
Auteur:
Lin, Chia-Yu Li, Chih-Shan
Verschenen in:
Aerosol science and technology
Paginering:
Jaargang 37 (2003) nr. 12 pagina's 939-946
Jaar:
2003-12
Inhoud:
Photocatalysis by TiO 2 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 TiO 2 filter and immobilized TiO 2 slide were used as photocatalytic surfaces. The light intensity levels included 240, 740, 1400, and 2100 μW/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 TiO 2 filter were found to be smaller than those of the TiO 2 slide for both B. subtilis and P. citrinum . At a light intensity of 740 μW/cm 2 , the calculated 50% survival inactivation time of the TiO 2 filter for B. subtilis and P. citrinum were 0.99 h and 2.55 h, respectively. The calculated 50% survival inactivation time of the TiO 2 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 .
Tijdschrift beschrijving