Effects of light intensity and titanium dioxide concentration on photocatalytic sterilization rates of microbial cells
- Osaka Univ., Toyonaka, Osaka (Japan)
Photocatalytic sterilization of Escherichia coli (bacterium) or Saccharomyces serevisiae (yeast) was conducted with a rectangular bubble-column photoreactor (40 mm in width, 40 mm in breadth, and 250 mm in height) containing slurried TiO{sub 2} semiconductor particles. The profiles of cell deactivation with sterilization time could be expressed in fair agreement with experimental data, based on a series-event model and a second-order kinetics with respect to the concentrations of microbial cells and oxidative radicals generated by photoexcitation of TiO{sub 2} particles. Sterilization rate constants for the microbes were determined under various conditions of TiO{sub 2} concentrations (0--5 {times} 0{sup {minus}1} kg/m{sup 3}) and average light intensities (0--223 W/m{sup 2}) in the photoreactor. Linear relationships were obtained between the rate constants and average light intensity at TiO{sub 2} concentration of 1 {times} 10{sup {minus}2} kg/m{sup 3}. When incident light intensity was kept constant (27 W/m{sup 2} for E. coli or 238 W/m{sup 2} for S. cerevisiae), the correlations between the rate constants and TiO{sub 2} concentration were interpreted considering a fraction of TiO{sub 2} particles adhered to the cells in slurry.
- OSTI ID:
- 404547
- Journal Information:
- Industrial and Engineering Chemistry Research, Vol. 35, Issue 11; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Bactericidal activity of TiO[sub 2] photocatalyst in aqueous media. Toward a solar-assisted water disinfection system
Continuous-sterilization system that uses photosemiconductor powders. [Escherichia coli]