Magnesium ferrite spinels as anode modifier for the treatment of Congo red and energy recovery in a single chambered microbial fuel cell

Nishat Khan; Abdul Hakeem Anwer; Mohammad Danish Khan; Ameer Azam; Alex Ibhadon; Mohammad Zain Khan

doi:10.1016/j.jhazmat.2020.124561

Magnesium ferrite spinels as anode modifier for the treatment of Congo red and energy recovery in a single chambered microbial fuel cell

J Hazard Mater. 2021 May 15:410:124561. doi: 10.1016/j.jhazmat.2020.124561. Epub 2020 Nov 14.

Authors

Nishat Khan¹, Abdul Hakeem Anwer², Mohammad Danish Khan², Ameer Azam³, Alex Ibhadon⁴, Mohammad Zain Khan⁵

Affiliations

¹ Environmental Research Laboratory, Department of Chemistry, Aligarh Muslim University, Aligarh 202 002, UP, India.
² Industrial Chemistry Research Laboratory, Depatment of Chemistry, Aligarh Muslim University, Aligarh 202 002, UP, India.
³ Department of Applied Physics, Zakir Husain College of Engineering and Technology, Aligarh Muslim University, Aligarh 202 002, UP, India.
⁴ Department of Chemical Engineering, Faculty of Science and Engineering, University of Hull, Cottingham Road, Hull HU6 7RX, United Kingdom.
⁵ Environmental Research Laboratory, Department of Chemistry, Aligarh Muslim University, Aligarh 202 002, UP, India; Industrial Chemistry Research Laboratory, Depatment of Chemistry, Aligarh Muslim University, Aligarh 202 002, UP, India. Electronic address: dr_mzain.fa@amu.ac.in.

PMID: 33246812
DOI: 10.1016/j.jhazmat.2020.124561

Abstract

Magnesium Ferrite (MgFe₂O₄) spinel structures prepared by a solid-state reaction was used as an anode modifier in the microbial fuel cell (MFC) treatment of Congo red dye. The performance of the reactors with unmodified stainless-steel mesh anode (CR-1) and MgFe₂O₄ coated stainless steel mesh anode (CR-2) were tested and compared followed by aerobic treatment. The peak power density was observed to be 295.936 (CR-1) and 430.336 mW/m² (CR-2) revealing increased bioenergy output and better electron transfer in the reactor with the MgFe₂O₄ modified anode. The final decolourisation efficiencies were found to be 92.053% for CR-1 and 98.386% for CR-2. The formation of metabolites (diaminonaphthalene-1-sulfonate, 1-(biphenyl-4-yl)-2-(naphthalene-2-yl) diazene, benzidine and phthalic acid, monoethyl ether) during the anaerobic-aerobic biotreatment of azo dye was confirmed using Gas chromatography coupled Mass spectrometry system. Scanning electron microscopy confirmed a uniform coating of MgFe₂O₄ on the anode surface with evidence of biofilm formation in the system. Electrochemical studies confirmed the superior performance of spinel coated anode with enhanced redox activity. In addition, the charge-discharge studies confirmed the high capacitive nature of the modified electrode improving the electrodes charge holding capacity. The study suggested an effective treatment strategy for the treatment of Congo red dye.

Keywords: Activated sludge process; Azo dye; Bioelectrochemistry; Bioenergy; Ferrite spinel; Single chamber MFC.