Balancing pH for enhanced bacterial community performance in microbial fuel cells: implications for bio-electricity generation and pollutant reduction

Authors

  • Mosammat Mustari Khanaum Civil, Construction and Environmental Engineering, North Dakota State University, Fargo, ND 58102, USA https://orcid.org/0000-0003-3494-909X
  • Shafiqur Rahman Agricultural Research and Development Program (ARDP), Central State University, 1400 Brush Row Road, Wilberforce, OH 45384, USA
  • Md. Saidul Borhan Texas Department of Transportation, Austin, TX 78744, USA
  • Peter Bergholz Department of Microbiological Sciences, North Dakota State University, Fargo, North Dakota, USA

DOI:

https://doi.org/10.17159/wsa/2024.v50.i3.4107

Keywords:

substrate pH, microbiome analysis, pollutant removal, water and cloth samples, exoelectrogens

Abstract

Microbial fuel cells (MFCs) represent a promising technology to generate bio-electricity and synchronously reduce wastewater pollutants. The presence of exoelectrogens in wastewater is critical for bio-electricity and pollutant reduction, but the performance of exoelectrogens at different pH levels remains unknown. This study aims to bridge this gap by offering an integrated approach to understanding the performance of exoelectrogens under varying substrate pH, particularly in bio-electricity generation and pollutant reduction in sugarbeet processing wastewater (SBWW). Three pH levels (ranging from acidic to alkaline) were studied and MFC's electricity output was measured. Later, current density, power density, and coulombic efficiency (CE) were calculated. Both pre- and post-experiment substrate samples were analysed with inductively coupled plasma (ICP). Furthermore, 16S rRNA gene analysis, DNA amplification, sequencing library preparation, and bioinformatics workflows on post-experiment samples of the substrate and anode samples were conducted. A diverse community of microorganisms was identified, especially Alphaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria (Geobacter). Bacteroidetes and Desulfovibrio were the major exoelectrogens responsible for electricity generation. Among the three pH levels tested, the most alkaline pH level (9.5±0.1) outperformed the others, achieving a 54% higher power density, 21% greater current density, and a 40% higher CE compared to the acidic pH level (6.5±0.1). Around 50–99% of pollutants were removed from the SBWW. The study revealed that Gammaproteobacteria thrive and perform better in alkaline environment.

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Published

2024-07-31

Issue

Section

Research paper

How to Cite

Balancing pH for enhanced bacterial community performance in microbial fuel cells: implications for bio-electricity generation and pollutant reduction. (2024). Water SA, 50(3 July). https://doi.org/10.17159/wsa/2024.v50.i3.4107