A Study of Bactericidal Effect and Optimization of Pathogenic Bacteria Using TiO₂ Photocatalyst

The photocatalytic degradation of Salmonella choleraesuis subsp. and Vibrio parahaemolyticus in water by TiO₂ catalysts was investigated in a batch reactor. After 30 min of irradiation with UV light in the presence of 1 mg/ml of TiO₂, death ratio of S. choleraesuis subsp. and V. parahaemolyticus was 60% and 83%, respectively. And complete killing of the cells was achieved after 3 h of illumination in the presence of TiO₂. We established the response surface methodology to investigate the effect of principal parameters on the pathogenic bacteria sterilization such as TiO₂ concentration, pH and temperature. By applying response surface analysis to the bactericidal effect of S. almonella choleraesuis subsp. and V. parahaemolyticus, we found that the cell death ratio was influenced significantly by the first order term of TiO₂ concentration.