Optimization of an Ion-Bridge-Based Microbial Fuel Cell for Treatment of a Municipal Wastewater Sample

This study investigates the effect of types and concentrations of salts and agar concentration that influence the performance of an ion-bridge-based microbial fuel cell (MFC) in terms of open circuit voltage (OCV) and chemical oxygen demand (COD) removal efficiency. When an optimal ion bridge was constructed by mixing 10.0%(w/v) agar with 4.0 M KCl solution and used in the MFC, it exhibited a maximum OCV of 340 mV and a COD removal efficiency of 66.8%(w/w). The MFC fed with a real wastewater (WW) sample performed slightly less, with the maximum OCV and COD removal efficiency decreasing to 315 mV and 56.2%(w/w), respectively, compared to that fed with pure glucose solution. The characteristic properties of the WW sample after the MFC treatment improved substantially and fell within the normal range of the effluent discharge. The OCV of the ion-bridge-based MFCs was not comparable to that of the proton exchange membrane (PEM)-based MFCs; however, it performed comparably in removing various pollutants from the WW sample. Future work may optimize other components and parameters to develop a cheap and simple ion-bridge-based MFC for real-world WW treatment and efficient bioelectricity generation.