This paper is dealt with conduct of experiments in Microbial fuel cell to find optimum electrode spacing for enhanced and sustained electricity generation. Besides, cow-dung fed MFCs is not subjected to cyclic-voltametric studies to evaluate their efficiency so far. Therefore, cyclic-voltametric study is also included for the first time in cow dung fed MFC. Two polycarbonate containers (500ml) one with 8cm (MFC-I) and another with 8cm (MFC-II) electrode spacing are fabricated and executed. 2% KMnO4 is used as catholyte and graphite material as electrodes. Experiment is conducted for 30days. Interestingly in a 30 days cycle, MFC-II generated a maximum voltage 1.3V on 18th day. Secondly, the reactor generated a sustained voltage of 1.0V and above for a period of 25 days continuously from 6th day to 29th day and exhibited better performance than MFC-I. On comparing, there was 18% increase in output voltage; 18% and 20% increase in current and current density respectively; 43% and 48% increase in power and power density respectively in MFC-II. Voltagram obtained for both reactors were fitted with US-convention model and analysed. MFC-II exhibited better reduction-oxidation reactions and showed one peak at +0.8V in the reduction phase without any interruption; redox coupling is almost symmetrical. Therefore, it is demonstrated that 4 cm (MFC-II) electrode spacing is ideal for harvesting sustained electricity.
Volume 11 | 01-Special Issue