Zoology · Ch 9 — Microbes in Human Welfare
Microbial Fuel Cell (MFC)
Microbial Fuel Cell (MFC)
A microbial fuel cell (MFC) is a bio-electrochemical device that generates electric current by exploiting the natural respiratory metabolism of bacteria, which is essentially a redox reaction moving electrons from an electron donor to an electron acceptor while mimicking bacterial interactions found in nature (Fig. 9.3). An MFC consists of an anode and a cathode separated by a proton exchange membrane. Bacteria at the anode oxidise an organic substrate (such as material present in wastewater), generating protons that diffuse across the membrane to the cathode, while the released electrons are instead forced to travel through an external circuit to reach the cathode, generating a usable electric current along the way. At the cathode, the arriving electrons and protons combine with oxygen (O2 + 4H+) to form water (2H2O), while carbon dioxide is released at the anode as the organic substrate is oxidised. Because …
What this figure shows. A schematic cross-section of a microbial fuel cell (MFC) showing an anode compartment containing the organic substrate and bacteria that oxidise it (releasing electrons and protons), separated by a proton exchange membrane from a cathode compartment where oxygen (O2 + 4H+) combines with the arriving electrons and protons to form water (2H2O), with CO2 shown being released at the anode as a by-product of substrate oxidation. Arrows trace the electron (e-) flow from anode through an external circuit to the cathode and the proton (H+) flow through the membrane, illustrating how …