Inactivation of Escherichia coli and somatic coliphage ΦX174 by oxidation of electrochemically produced Fe2+

Journal article (2022)

Authors

Bruno Bicudo Sanitary Engineering - CEG
Gert Jan Medema KWR Water Research Institute, Sanitary Engineering - CEG , Michigan State University
G.J. Medema KWR Water Research Institute, Sanitary Engineering - CEG , Michigan State University
Gertjan Medema KWR Water Research Institute, Sanitary Engineering - CEG , Michigan State University
D. van Halem Sanitary Engineering - CEG
Research Group
Sanitary Engineering (CEG) (TU Delft)
Copyright: © 2022 Bruno Bicudo, G.J. Medema, D. van Halem
DOI: https://doi.org/10.1016/j.jwpe.2022.102683
More Info
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Published Date

2022

Language

English

Faculty

Civil Engineering & Geosciences

Department

Water Management

Research Group

Sanitary Engineering

Abstract

Electrochemical ferrous iron (Fe2+) wastewater treatment is gaining momentum for treating municipal wastewater due to its decreasing costs, environmental friendliness and capacity for removal of a wide range of contaminants. Disinfection by iron electrocoagulation (Fe-EC) has been occasionally reported in full scale industrial applications, yet controversy remains regarding its underlying elimination mechanisms and kinetics. In this study, it was demonstrated that substantial inactivation can be achieved for Escherichia coli WR1 (5 log10) and somatic coliphage ΦX174 (2–3 log10). Electrochemically produced Fe2+ yielded similar inactivation as chemical Fe2+. Reactive oxygen species (ROS)-quenching experiments with TEMPOL confirmed that E. coli inactivation was related to the production of Fenton-like intermediates during Fe2+ oxidation. The observed E. coli disinfection kinetics could be mathematically related to Fe-EC current intensity using a Chick-Watson-like expression, in which the amperage is surrogate for the disinfectant's concentration. We hereby show that it is possible to mathematically predict disinfection based on applied Fe dosage and dosage speed. Phage ΦX174 inactivation could not be described in a similar way because at higher Fe dosages (>20 mg/l), little additional inactivation was observed. Also, ROS-quencher TEMPOL did not completely inhibit phage ΦX174 removal, suggesting that additional pathways are relevant for its elimination.