The Use of Accumulated Charge Density of a Bioanode to Estimate Maximum Current in a Bioelectrochemical System

Abstract

The maximum current density (jmax) is of importance to the modeling of current produced in a bioelectrochemical system (BES). This study explores an alternative to biomass and biofilm thickness, the accumulated charge density (τ) of electroactive bacteria on the bioanode, to estimate the jmax value. The τ values of five carbon‐based bioanodes are chronoamperometrically determined in a substrate‐depleted solution. The graphite felt bioanode acclimated for 1, 2, 4, and 6 batches exhibits τ values of 6.14, 11.80, 22.23, and 30.24 C m−2, respectively, and jmax values of 5.31, 6.69, 14.01, and 19.62 A m−2, respectively. A linear correlation between τ and jmax is achieved and can be expressed as jmax=0.64τ. The τ and jmax values of four other carbon‐based bioanodes also follow a linear relationship, with coefficients of approximately 0.64. These results imply that τ is a key parameter for estimating jmax in the BES without the need to determine biomass and biofilm thickness.