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Integrated air cathode microbial fuel cell-aerobic bioreactor set-up for enhanced bioelectrodegradation of azo dye Acid Blue 29

Lookup NU author(s): Dr Da Li, Shamas Tabraiz, Dr Burhan ShamuradORCiD, Emeritus Professor Keith Scott, Professor Eileen Yu



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


In this study, an azo dye (Acid Blue 29 or AB29) was efficiently degraded with acetate as co-substrate into less contaminated biodegraded products using an integrated single chamber microbial fuel cell (SMFC)-aerobic bioreactor set-up. The decolorization efficiencies were varied from 91 ± 2% to 94 ± 1.9% and more than 85% of chemical oxygen demand (COD) removal was achieved for all dye concentrations after different operating time. The highest coulombic efficiency (CE) and cell potential were 3.18 ± 0.45% and 287.2 mV, respectively, for SMFC treating 100 mg L−1 of AB29. Electrochemical impedance spectroscopy (EIS) revealed that the anode resistance was 0.3 Ω representing an entirely grown biofilm on the anode surface resulted in higher electron transfer rate. Gas chromatography coupled mass spectrometry (GC–MS) investigation demonstrated that initially biodegradation of AB29 started with the cleavage of the azo bond (-N=N-), resulted the biotransformation into aromatic amines. In successive aerobic treatment stage, these amines were biodegraded into lower molecular weight compounds. The 16S rRNA microbial community analysis indicated that at phylum level, both inoculum and dye acclimated cultures were mainly consisting of Proteobacteria which was 27.9, 53.6 and 68.9% in inoculum, suspension and anodic biofilm, respectively. At genus level, both suspension and biofilm contained decolorization as well as electrochemically active bacteria. The outcomes exhibited that the AB29 decolorization would contest with electrogenic bacteria for electrons.

Publication metadata

Author(s): Khan M, Li D, Tabraiz S, Shamurad B, Scott K, Khan MZ, Yu EH

Publication type: Article

Publication status: Published

Journal: Science of Total Environment

Year: 2021

Volume: 756

Print publication date: 20/02/2021

Online publication date: 26/11/2020

Acceptance date: 03/11/2020

Date deposited: 13/08/2021

ISSN (print): 0048-9697

ISSN (electronic): 1879-1026

Publisher: Elsiver


DOI: 10.1016/j.scitotenv.2020.143752


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Funder referenceFunder name
NE/ L01422X/1