Mfc fundaments and possibilities

Introduction

The high energy requirement of conventional sewage treatment systems are
demanding for the alternative treatment technology which will be cost effective and
require less energy forits efficient operation. In this alternative, MFC can play an important role..

Microbial fuel cells are not new – The idea of using microbial cells in order to attempt to produce electricity wasfirst found at the end of the nineteenth century. However, it is only recently that microbial fuel cells with an enhanced power output have been developed providing possible opportunities for practicalapplications.


How does a microbial fuel cell work? 

A microbial fuel cell is a device that converts chemical energy to electrical energy by the catalytic reaction of microorganisms. There aremany types of microbial fuel cells reactors throughout the world, however, all reactors share the same operating principles. A typical microbial fuel cell consists of anode and cathode compartmentsseparated by a membrane. When bacteria are placed in the anode chamber of a cell that is free of oxygen, they attach to an electrode.  Because they don’t have oxygen, they must transfer the electronsthat they obtain from consumption (oxidation) of their food somewhere else – they transfer them to the electrode. Electrons go to the anode, while the counter electrode (the cathode) is exposed tooxygen. The two electrodes are at different potentials (about 0.5 V), electrons are transferred to the cathode compartment through an external electric circuit, while protons are transferred to the cathodecompartment through the membrane. Electrons and protons are consumed in the cathode compartment, combining with oxygen to form water.

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Figure 1. The working principle of a microbial fuelcell. Source: “Trends in Biotechnology” vol.23 no.6 June 2005

Applications of microbial fuel cell technology

Microbial fuel cells provide new opportunities for the sustainable production of...