Pulsed ultra-violet inactivation spectrum of Escherichia coli

Wang, T. and MacGregor, S.J. and Anderson, J.G. and Woolsey, G. (2005) Pulsed ultra-violet inactivation spectrum of Escherichia coli. Water Research, 39 (13). pp. 2921-2925. ISSN 0043-1354

Abstract

Inactivation of Escherichia coli is examined using ultra-violet (UV) radiation from a pulsed xenon flashlamp. The light from the discharge has a broadband emission spectrum extending from the UV to the infrared region with a rich UV content. The flashlamp provides high-energy UV output using a small number of short-duration pulses (30 μs). The flashlamp is used with a monochromator to investigate the wavelength sensitivity of E. coli to inactivation by the pulsed UV light. Using 8 nm wide pulses of UV radiation, the most efficient inactivation is found to occur at around 270 nm and no inactivation is observed above 300 nm. A pyroelectric detector allows the energy dose to be determined at each wavelength, and a peak value for E. coli population reduction of 0.43 log per mJ/cm2 is measured at 270 nm. The results are compared with the published data available for continuous UV light sources.

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