Biotechnology-Microbial Fuel Cells - Lab Report Example

This project, therefore, aimed at establishing the voltage generated from three microbial species Shewanella oneidensis, Pseudomonas trivialis and Escherichia coli using H-type microbial fuel cells using synthetic wastewater as the substrate. E. coli generated the highest voltage and yielded a power density of 192.887 mW/m2 followed by S. oneidensis with 134.429 mW/m2 and least of all P. trivialis with 89.098 mW/m2. P. trivialis recorded the highest levels of COD removal (140%) followed by E. coli (133%) and finally S.

oneidensis (44.08%). However, the coulombic efficiencies were lower than the literature values. These results meant that of the three microorganisms, E. coli was the best in voltage generation and that further studies were necessary to improve further the overall efficacy of microbial fuel cells. Energy is the most important constituent in the growth of any economy. The most commonly used sources of energy in most energy-requiring processes are fossil fuels (Devasahayam & Masih 2012). However, the use of such fuels poses several challenges such as their undependability as they are not renewable and the vast environmental pollution that accompanies their use.

These challenges have seen the quest for renewable energy substitutes that do not cause environmental contamination. Microbial fuel cells provide an option of the production of environmentally sustainable energy through the process of treating organic waste and obtaining energy concurrently (Kim et al. 2007). Microbial fuel cells are electrochemical gadgets that employ electrochemically active bacteria to produce electric currents from organic wastes (Ghangrekar & Shinde 2003; Cao et al. 2009; Wei et al. 2012). The electrochemically active bacteria consume the organic substrates by oxidation leading to the movement of electrons to the anode, which accepts the electrons.

The bacteria obtain energy for metabolism by conveying electrons from an electron donor such as sucrose to an electron acceptor for instance oxygen (Devasahayam & Masih 2012). This transfer causes electrical conductivity and forms water as a product. The energy produced can be used to operate machines that are not heavy power consumers such as remote sensors (Ringeisen et al. 2006).