Decomposition of Microcystis aeruginosa and Microcystin-LR by TiO2 Oxidation Using Artificial UV Light or Natural Sunlight

Abstract

In this study, it is reported the destruction of Microcystis aeruginosa and the toxin microcystin-LR (MC-LR) by photolysis and TiO2 photocatalysis in a lab-scale prototype using artificial UV light and at pilot-scale plant using natural solar radiation, as UV photon source. TiO2 photocatalysis showed to be effective in the destruction of M. aeruginosa (similar to 5-log order decrease) and in the degradation of the MC-LR released into the aqueous solutions, in the short reaction period of 5-15 min, even at extremely high concentrations. The photocatalytic process can be considered as a viable alternative for disinfection of contaminated water by cyanobacteria, especially in countries with high solar insolation. However, the use of UV light or sunlight alone, as well as TiO2 in dark is not sufficient to achieve complete elimination of cells and degradation of MC-LR in full-scale water treatment.