Microbial Fuel Cell: Harnessing Bioenergy from Yamuna Water

Microbial Fuel Cells (MFCs) hold a great potential in generation of electricity and has proved as an alternative source of renewable energy. In the present research work, a mediator-less MFC with an anaerobic anode & aerobic cathode chamber linked with a salt bridge for the exchange of generated protons is constructed. Yamuna water from four different locations in Delhi viz., Palla, ITO, Nizamuddin Bridge and Okhla Barrage were collected to study the generation of electricity and pure culture of Escherichia coli & Bacillus subtilis were taken as controls. Glucose is used as substrate, which is considered as an instantaneous source of energy for biological systems. The pure cultures of E. coli and B. subtilis generated electric current varying from 326 - 522 mV and 260 - 580 mV respectively at different cellular concentrations. An increasing trend is observed when the cell counts were doubled. A variable increase in generation of electricity is obtained ie., 80 - 360 mV (Palla), 400 - 620 mV (ITO), 280 - 360 mV (Nizamuddin Bridge) and 320-480 mV (Okhla Barrage) respectively. This is higher as compared to the pure cultures used. The Yamuna water samples are deemed to contain a consortium of bacteria namely E. coli, Bacillus subtilis, Lactobacillus plantarum, L. casei, Streptococcus lactis, Rhodopseudomonas palustris, Rhodobacter sphaeroides, S. cerevisiae, Candida utilis, Streptomyces albus, S. griseus, Aspergillus and Mucor hiemalis. Thus implying that, in consortium the other microbes enhance the performance of the MFC. Secondly, chemical compounds (Fe+++, NO2--, SO4 -- ) present in the Yamuna water may act as mediators of the electrons transporter to the anode and hence increasing the potential difference.