Photoreactor for airborne microorganism inactivation employing UV radiation

MARÍA EUGENIA MARTÍNEZ RETAMAR; MARISOL DANIELA LABAS; RODOLFO JUAN BRANDI

Rio de Janeiro

Encuentro; VI Encontro sobre Aplicações Ambientais de Processos Oxidativos Avançados; 2011

Programa de Engenharia Quimica - COPPE/UFRJ

Indoor air pollution is one of the top five environmental risks to public health according to the U.S.EPA Science Advisory Board. Currently, there is great interest in the engineering of air pollution control to reduce indoor infectious diseases. Germicidal UV systems are one of the most promising technologies to inactivate pathogenic microorganisms. The goal of present work is to study the inactivation of airborne microorganisms, using an UV photoreactor. In fact, an experimental device was designed and constructed in order to obtain experimental data on inactivation UV airborne microorganisms. The experimental device consists basically of three parts: a generation system of feed stream, an annular photoreactor, and a bioaerosol capture system. The system is irradiated by an UV lamp emitting at 253.7 nm wavelength. A nebulizer was designed and built to generate bioaerosol. A strain of E. coli was selected as test organism. An impinger collects bioaerosols in a capture liquid which can then be plated out for microbial counts. From data obtained in preliminary experimental runs it was possible to determine the level of reduction in bacterial concentration between input and output of the reactor, for different operating conditions. The use of germicidal UV radiation was found to be effective in inactivating E. coli under laboratory conditions studied.