Issue 3, 2017

Inactivation of E. coli using a novel TiO2 nanotube electrode

Abstract

The performance of electrochemical processes highly depends on the properties of electrodes and development of cost-effective anode materials plays an important role in supporting future adoption of electrochemical technologies for environmental applications. In this study, novel TiO2 nanotube anodes were fabricated via a simple electrochemical method and tested for inactivation of a model microbial contaminant E. coli, using a filter-press type cell with stainless steel as the cathodes. Effects of current density applied (0.66–2.63 mA cm−2), electrolyte concentration (0.3–3 mM NaCl), and different electrolytes (NaCl, Na2SO4, Na2HPO4, NaNO3, and NaHCO3) on E. coli inactivation were investigated. Electrochemically generated oxidizing species were measured as free chlorine and production of reactive oxygen species (ROS) were examined using probe compounds. Reactive chlorine species were formed mainly via a ˙OH-mediated pathway and found to be the dominant species responsible for E. coli inactivation in the presence of Cl. Higher E. coli reduction efficiency was obtained in inert electrolytes using TiO2 nanotube anodes compared with other electrodes reported in the literature, which can be ascribed to the formation of ROS such as ˙OH and H2O2 and possibly electrolyte-specific oxidants such as sulfate and phosphate radicals. Furthermore, it has been demonstrated that the novel TiO2 nanotube anode can effectively achieve 5–7.5 log reduction of E. coli with low byproduct formation (e.g. ClO3, THMs) and energy consumption (0.1–0.19 kW h m−3 for 4 log reduction) in real water matrices.

Graphical abstract: Inactivation of E. coli using a novel TiO2 nanotube electrode

Supplementary files

Article information

Article type
Paper
Submitted
12 Nov 2016
Accepted
14 Feb 2017
First published
15 Feb 2017

Environ. Sci.: Water Res. Technol., 2017,3, 534-545

Inactivation of E. coli using a novel TiO2 nanotube electrode

A. Ahmadi and T. Wu, Environ. Sci.: Water Res. Technol., 2017, 3, 534 DOI: 10.1039/C6EW00319B

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