Issue 1, 2017

Impact of environmental conditions on bacterial photoreactivation in wastewater effluents

Abstract

Photoreactivation is a process where ultraviolet (UV)-induced damage to the DNA of microorganisms can be reversed by exposure to near UV and visible light. To date, most photoreactivation experiments have been carried out under laboratory conditions using standard microorganisms that do not reflect the natural conditions of municipal wastewater effluents. Photoreactivation could increase the concentration of pathogens released into natural systems, leading to negative impacts on fish, shellfish, and clams. In addition, pathogen release can increase health risks of downstream activities, such as swimming. This study focused on the photoreactivation of total coliforms in municipal wastewater effluents under natural sunlight conditions. The concept of ‘effective reactivation fluence’ (ERF) is used to evaluate and normalize the results from various light sources for a direct comparison. ERF values higher than 30 J cm−2, in conjunction with lowered nutrient concentrations (dilution of effluents with river water), decreased the photoreactivation of total coliforms. In contrast, higher temperatures (up to 25 °C) and blocking the UV-B portion of natural sunlight using a polyethylene terephthalate (PET) bottle increased their photoreactivation. The results of this research will provide guidance to wastewater plant operators on the potential need to minimize the level of photoreactivation in effluents before the effluents were released into receiving water bodies.

Graphical abstract: Impact of environmental conditions on bacterial photoreactivation in wastewater effluents

Supplementary files

Article information

Article type
Paper
Submitted
12 Sep 2016
Accepted
13 Dec 2016
First published
14 Dec 2016

Environ. Sci.: Processes Impacts, 2017,19, 31-37

Impact of environmental conditions on bacterial photoreactivation in wastewater effluents

S. Shafaei, N. Klamerth, Y. Zhang, K. McPhedran, J. R. Bolton and M. Gamal El-Din, Environ. Sci.: Processes Impacts, 2017, 19, 31 DOI: 10.1039/C6EM00501B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements