Studying Performance of Microbial Fuel Cell Inoculated with Shewanella Oneidensis MR-1 for Copper Recovery

Conventional methods of extracting metals involve fragmentation and processing of ores through toxic chemicals. Along with the high cost and energy for processing low grade ores, dealing with immense amount of waste rock is a formidable challenge for the mining industry. Copper at high concentrations becomes anthropogenic and can be particualarly be found in acid mine drainage (AMD). Bio-electrochemical systems provide low operating costs and are a sustainable alternative for many industrial applications. Microbial fuel cells (MFC) have advanced from electricity production to wastewater treatment. Species of bacteria known as exoelectrogen can transfer electrons from their extracellular structures such as pili and flavins. These bacteria have a very well-defined metabolic pathways leading to terminal electron acceptors. Shewanella Oneidensis MR-1 has been one of the most widely studied exoelectrogen. As part of my undergraduate thesis, I am studying the kinetics of electron transport in a two-chamber microbial fuel cell inoculated with Shewanella Oneidensis MR-1 under lactate substrate and copper sulphate solution at cathode. The study also explores recovery of copper at carbon neutral cathode. The maximum power density achieved by the cell was 13 mW/m² with 40% removal of copper from catholyte. Furthermore, I am working on genetically engineering the strain by overexpressing genes encoding for proteins playing pivotal role in electron transfer to boost extracellular electron transfer, thereby generating higher voltage and increasing rate of copper recovery. I look forward to more development on applications of MFCs and inspire research in scaling up bio-electrochemical systems to meet industry demands.