Scaling-up of the photocatalytic inactivation of E. coli with TiO2 in suspension

MARUGAN, J.; VAN GRIEKEN, R.; PABLOS, C.; SATUF, M.L.; CASSANO, A.E.; ALFANO, O.M.

Congreso; IWA Specialist Conference 2011 - Water and Industry; 2011

Chlorination processes for disinfection of drinking water supplies have raised public concerns as a consequence of the formation of potentially harmful chloro-organic disinfection by-products (DBPs) coming from the reaction with naturally-occurring organic matter. Among the processes currently in development, semiconductor photocatalysis has emerged as a very attractive, environmentally friendly technology for water disinfection (Malato et al., 2009; Chong et al., 2010). Since the early work of Matsunaga et al. in 1985, many research groups have reported the application of photocatalytic processes for the inactivation of different kinds of pathogenic microorganisms, such as bacteria, viruses, algae, fungi or protozoa. Most of the work in the literature was focused on the study of operational parameters such as light intensity and titanium dioxide concentration, on the use of solar light and the influence of the chemical composition of water. However, only relatively few developments have been achieved from the scaling-up and the photoreactor engineering viewpoints, being most of the research efforts devoted to the investigation of the fundamental mechanisms and phenomenological aspects of the process. In contrast with thermal reactions in which isothermal conditions can be easily achieved to determine the kinetic parameters, the kinetic modelling of the photocatalytic processes with scaling-up purposes requires the evaluation of the radiation profiles inside the photoreactor (Alfano et al. 1997). The aim of this work is the development of a methodology for the design and scaling-up of large slurry photoreactors for the photocatalytic inactivation of bacteria with TiO2 in suspension.