Advances in anode configurations for a microbial fuel cell via a computational fluid dynamics electrochemistry and its experimental validation

Abstract

BACKGROUNDThe experimental process for optimizing microbial fuel cell (MFC) design under different electrode geometries is restricted. An MFC can be defined as a bio‐electrochemical system (BES) that facilitates the direct conversion of the chemical energy stored in organic matter into electrical energy by harnessing the metabolic activity of microorganisms. Computational fluid dynamics (CFD) tools allow the simulation and evaluation of electro‐analysis phenomena such as cyclic voltammetry and chemical reactions, which can help the optimization of the BESs. In this study, MFC is designed to provide the maximum peak current and efficiency for the applied voltage on various working (or anode) electrode geometries (i.e. hexagonal, square, pentagonal, circular, triangular, rectangular, and rhombus).RESULTSThe CFD simulation results demonstrate that a configuration with a larger perimeter value and surface area (i.e. hexagonal design) of the working electrode shows a higher peak current (2422.75 mA) than other configurations. The experimental findings supported the simulation result and reveal that a hexagonal electrode containing a MFC setup produces a maximum power density of 22.41 ± 0.32 mW m−3 and a current density of 41.58 ± 0.35 mA m−2. The MFC operation demonstrated adequate bioelectricity generation of 540 ± 03 mV on Day 4 of operation at 1000 Ω. Additionally, maximum reduction in chemical oxygen demand (76.13 ± 0.5%) and coulombic efficiency (76.03 ± 0.4%) was achieved for synthetic wastewater using a hexagonal MFC.CONCLUSIONBased on these fundamental discoveries, the CFD simulation and its experimental validation considerably drag focus toward the possibility of employing COMSOL Multiphysics software for system improvement of different MFC system applications. © 2023 Society of Chemical Industry (SCI).