Photocatalytic inactivation of microorganisms in water under ultraviolet C irradiation and TiO2

Abstract

Microbial contamination is one of the most important problems in the preparation of many herbal products. This study aimed to use nanoparticles and UVC radiation, which were considered in some previous laboratory studies. The contaminated water was entered into a photocatalytic reactor, and microbial removal efficiency of TiO2 alone and in the presence of UV was evaluated under different retention times (0–90 min) and concentrations of TiO2 nanoparticles (0.1, 0.2, 0.4, 0.8, 1 and 2 mg/ml). Efficiency of the reactor increased with increase in the retention time in the presence of UV. Simultaneous treatment of the contaminated water with both UV and TiO2 nanoparticles had a similar outcome. However, only a slight reduction in the concentration of microbes was noted in the presence of TiO2 in high concentrations. Considering the significant antimicrobial effects of nanoparticles, it is suggested to conduct similar studies on the effect of these compounds using animal models. By obtaining further information on other antimicrobial properties of such compounds, they could be utilized for removal of microbial surface contamination, especially in clinical settings.