The Effect of Immobilized Anatase Photocatalyst Nanopowder in the UV-A Mediated Killing of Escherichia coli B23

Abstract

Solar water disinfection (SODIS) is a method using ultraviolet-A radiation and heat for inactivating microbial activity in water. Adding suspended anatase (TiO ) greatly improves 2 the disinfection efficiency. It is thought that the mechanism of microbial killing by UV-A and anatase may be mediated through the generation of reactive oxygen species (ROS) that damage the microbial lipid membranes. This experiment tested the effects of UV-A radiation with an immobilized anatase photocatalyst on the viability of Escherichia coli B23 ( E.coli B23) in sterile distilled water. The extent of ROS formation was measured through the formation of the lipid peroxidation product malondialdehyde (MDA). Our experiments demonstrated the effectiveness of immobilized anatase on the formation of the lipid peroxidation product MDA, however the formation of MDA did not correlate to decreased viability of E. coli B23.