Effect of bluff body embedded in flow channel on power performance of microbial fuel cell

Abstract

The microbial fuel cell (MFC) has emerged as an eco-friendly method for generating clean energy from wastewater. However, its current power performance falls short of meeting commercial application requirements, highlighting the urgent need for power enhancement. To address this, the implementation of bluff bodies within the MFC channel is a proof of concept to enhance nutrient mass transport without the need for external energy input. In this study, fluid simulation was first conducted to analyze the impact of different bluff body designs on flow regimes. The results showing bluff body having spread-out six circles arrays with a height of 0.5 mm (6C_H5) led to a wide velocity distribution within the flow channel, high velocity, and no solute accumulation on the electrode surface, thereby facilitating increased nutrient coverage during transport. Through experimental confirmation, MFC with 6C_H5 achieved an impressive 154 % increase in maximum power density compared to without a bluff body. The outcome can be attributed to sufficient nutrient acquisition for the bacteria to generate more power due to better nutrient transport and a shear environment. The significant finding of the bluff body’s impact on the fluid dynamic aspect has proven the feasibility of enhancing MFC power performance.