Photocatalytic disinfection of natural well water contaminated by Fusarium solani using TiO2 slurry in solar CPC photo-reactors

Phytopathogenic infection of food crops with fungi such as Fusarium spp. is a major problem faced by the farming industry and it has a major economic impact through the reduction in crop yields and through the need to use chemical pesticides to control the problem. As fungi are resistant to many disinfecting agents, which may also be phytotoxic or create environmental problems, more and more effort is being invested in the development of new control techniques for phytopathogenic fungi. It has recently been demonstrated on a small scale that the Fusarium, and within it, Fusarium solani, a plant and human pathogen, is susceptible to solar photocatalytic disinfection with TiO2 in distilled water. We report on disinfection of water contaminated by F. solani spores using a solar bottle reactor and a 14-L CPC solar photoreactor with distilled and also with natural well water. It was possible to reach high disinfection yields with different TiO2 concentrations (from 10 to 500 mg L-1) and state flow conditions (20 L/min), at these Volumes, not only in distilled, but also in natural well water. We also give the inactivation rate constant for the first stage of photocatalysis under the various experimental conditions, for selection of the best parameters for disinfecting water with phytopathogenic fungi in a future pilot treatment plant. (C) 2009 Elsevier B.V. All rights reserved.