This study assessed the spatial distribution of biofilm conductivity (Kbio) across a multi-centimetre long anodic biofilm grown on an eight-electrode anode array at different growth conditions. A strong correlation was found between the spatial distribution of Kbio and the anodic biofilm thickness (Lf). The Kbio for different electrode pairs ranged between 0.6 and 0.7 mS/cm for Lf of 17–22 µm and increased to 1.15–1.64 mS/cm upon Lf growth to 38–53 µm. This increase in Kbio was accompanied by increase in current density from 1.15 ± 0.12 A/m2 to 2.1 ± 0.02 A/m2. Low half saturation potential was consistently found for electrode pairs having high values of Kbio and Lf. Microbial community revealed the dominance of Geobacter (>85%) on all electrode pairs. Acetate concentration significantly influenced the spatial distribution of Kbio. Long-term acetate starvation (3 days) resulted in up to 83% drop in Kbio along with decrease in current density to marginal values (<0.3 A/m2). However, the Kbio and current density rapidly recovered on restoring the acetate feed.

Biofilm conductivity, Biofilm thickness, Extracellular electron transfer, Geobacter, Microbial electrochemical technologies
Chemical Engineering Journal
Department of Civil and Environmental Engineering

Hussain, A. (Abid), Lee, J. (Jangho), Ren, H. (Hao), & Lee, H.-S. (Hyung-Sool). (2021). Spatial distribution of biofilm conductivity in a Geobacter enriched anodic biofilm. Chemical Engineering Journal, 404. doi:10.1016/j.cej.2020.126544