Issue 6, 2023

Low-irradiance inactivation kinetics of Escherichia coli during prolonged exposure to ultraviolet-C radiation

Abstract

There is growing interest in using continuous, low-irradiance germicidal ultraviolet (UV) radiation to prevent bacterial attachment, growth, and biofilm formation on surfaces through water distribution pipes, appliances, and point-of-use plumbing. This study explored the low irradiance dose response of surface-bound Escherichia coli (E. coli). A linear model was used to calculate the pseudo-first-order inactivation rate constant (k′), and a minimum irradiance (μW cm−2) was established to achieve inactivation of surface-bound organisms in a nutrient-rich environment. The k′ for irradiance above 0.21 μW cm−2 was calculated to be 1.06 ± 0.05 cm2 mJ−1. The kinetic model reveals that UV irradiance above 0.21 μW cm−2 can result in up to 6 log inactivation at a dose of <6.0 mJ cm−2. The minimum UV irradiance required for complete inactivation of surface-bound E. coli during prolonged exposure was averaged to be 0.38 ± 0.11 μW cm−2 and 0.18 ± 0.02 μW cm−2 for 265 nm and 280 nm wavelength, respectively. This study provides new knowledge and guidance to design technologies for disinfecting surfaces and a control strategy for biofilm prevention with very low UV irradiance (μW cm−2).

Graphical abstract: Low-irradiance inactivation kinetics of Escherichia coli during prolonged exposure to ultraviolet-C radiation

Article information

Article type
Paper
Submitted
21 Nov 2022
Accepted
28 Mar 2023
First published
21 Apr 2023
This article is Open Access
Creative Commons BY license

Environ. Sci.: Water Res. Technol., 2023,9, 1654-1662

Low-irradiance inactivation kinetics of Escherichia coli during prolonged exposure to ultraviolet-C radiation

M. S. Mohsin, K. Fitzpatrick, M. Avdic, J. Fiorentino and M. Lanzarini-Lopes, Environ. Sci.: Water Res. Technol., 2023, 9, 1654 DOI: 10.1039/D2EW00886F

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements