Identification of predominant bacterial species involved in microbial fuel cell assisted electricity generation using fish market wastewater

Abstract

Microbial Fuel Cells (MFCs) are a rapidly expanding area of sustainable technology that treats wastewater and generates energy from biodegradable wastes at the same time. However, the power generation from MFC is strongly restricted by the biofilm (microorganism) electron transfer rate which improves electrical power density. The current study provides insight into the effectiveness in electricity production, and wastewater treatment using MFC technique by identifying microbial electricigens on various electrodes using raw fish market wastewater effluent as a substrate. Galvanised iron, aluminium, brass, stainless steel (metal-based electrodes), and graphite rod (carbon-based electrode) were used for the study. MALDI-TOF MS tests were performed to identify the predominant bacterial species from each electrode containing reactors. Raoultella ornithinolytica, Comamonas testosteroni, and Klebsiella pneumonia were among the microbes that were identified and isolated from the anodic biofilm of different MFC reactors. In the current study, four out of the five reactors contained R. ornithinolytica, which was found to be effective at generating electricity. The fuel cell produced maximum current density of 325.13 mA/m2, and power density of 87.78 mW/m2. The COD removal efficiency was found to be 86 %. This study demonstrates the significance of bacterial community characterization and identification in MFC-assisted current generation in fish market wastewater.