Work

Impact of extended starvation conditions on bioelectrocatalytic activity of a methane-producing microbial electrolysis cell

Year: 2024

Type: article

Abstract: • Extended starvation period (90 days) applied to fully biological CH 4 -producing MEC. • Anodic biofilm characterized by redox sites identified with cyclic voltammetry. • Complete recovery of anodic electrocatalytic activity after two starvation periods. • Starvation preserved redox sites with a formal potential lower than −0.18 V vs SHE. The performance of a methane-producing microbial electrolysis cell (MEC) markedly relies on the activity and resilience of its electroactive anodic biofilm. Here, the capability of an MEC anodic biofilm to recover following extended starvation periods (90 days) and to function under different applied anode potentials (i.e., +0.20 and −0.10 V, vs. Standard Hydrogen Electrode-SHE) was investigated. Cyclic voltammetry proved to be an insightful means to characterize the biofilm electrocatalytic activity and to track the dynamics of biofilm reactivation. Under all tested conditions the anodic biofilm rapidly and completely recovered from starvation in less than 144 h. However, starvation reduced the electron transfer redundancy of the biofilm causing the disappearance of redox sites operating at the more positive potentials (around 0.0 V vs. SHE) and retaining those having a formal potential lower than −0.18 V vs. SHE. This study presents compelling evidence for the resilience and efficiency of methane-producing MEC.

Source: Bioresource Technology

DOI: 10.1016/j.biortech.2024.131491