Effect of biofilm formation on the performance of microbial fuel cell for the treatment of palm oil mill effluent

Abstract

Anode biofilm is a crucial component in microbial fuel cells (MFCs) for electrogenesis. Better knowledge about the biofilm development process on electrode surface is believed to improve MFC performance. In this study, double-chamber microbial fuel cell was operated with diluted POME (initial COD = 1,000 mg L(-1)) and polyacrylonitrile carbon felt was used as electrode. The maximum power density, COD removal efficiency and Coulombic efficiency were found as 22 mW m(-2), 70 and 24 %, respectively. FTIR and TGA analysis confirmed the formation of biofilm on the electrode surface during MFC operation. The impact of anode biofilm on anodic polarization resistance was investigated using electrochemical impedance spectroscopy (EIS) and microbial community changes during MFC operation using denaturing gradient gel electrophoresis (DGGE). The EIS-simulated results showed the reduction of charge transfer resistance (R ct) by 16.9 % after 14 days of operation of the cell, which confirms that the development of the microbial biofilm on the anode decreases the R ct and therefore improves power generation. DGGE analysis showed the variation in the biofilm composition during the biofilm growth until it forms an initial stable microbial community, thereafter the change in the diversity would be less. The power density showed was directly dependent on the biofilm development and increased significantly during the initial biofilm development period. Furthermore, DGGE patterns obtained from 7th and 14th day suggest the presence of less diversity and probable functional redundancy within the anodic communities possibly responsible for the stable MFC performance in changing environmental conditions.

Fast Biofilm Formation and Its Role on Power Generation in Palm Oil Mill Effluent Fed Microbial Fuel Cell

“…It is interesting to note that the anode charge transfer resistance (R ct ) after 14 days of continuous microbial growth was more or less same as that on day 7. Our previous results [20] showed that stable biofilm can be formed within even 7 days of MFC operation and these results support the same. A biofilm formed on the electrode surface during the MFC operation with anaerobic sludge, was usually enriched with electrochemically active bacteria [13] which might reduce the charge transfer resistance.…”

“…A biofilm formed on the electrode surface during the MFC operation with anaerobic sludge, was usually enriched with electrochemically active bacteria [13] which might reduce the charge transfer resistance. As a result, the development of the microbial biofilm on the anode was found to be decreased the polarization resistance and facilitates the kinetics of the electrochemical reactions [20]. This investigation confirmed the fact that the anode charge transfer resistance is strongly influenced by the microbes growing on the anode surface.…”

“…The biofilm development was fast between days 3 and 7 point out a significant enhancement in the cell performance. This improvement may be caused by the effect of microorganisms on the electrode surface amid efficient biofilm formation [20]. The maximum performance was observed on the 7th day of biofilm growth on the anode as shown in Figure 1b.…”

“…The voltage and current across an external 1 kΩ resistor was measured every 15 min by using digital multimeter with data logger (Fluke 289) which recorded and stored the data [20]. Later, it was retrieved from the multimeter using computer with fluke view forms software [21].…”

Effect of Composting Parameters on the Power Performance of Solid Microbial Fuel Cells

“…The chamber material was made from an acrylic sheet, and carbon felt was selected as the electrode material. As carbon felt has a high porosity and large surface area, and is conducive to microbial growth [13], adhesion, and reduction of activation impedance [14], it was considered the best choice. The carbon felt was pretreated before the study by being soaked and heated at a condition of 90°C with a volume of 10% hydrogen peroxide solution for 3 h, and then air-dried so as to increase the adhesion and proliferation of microbes [15].The different chambers of the SMFCs were manufactured for particular experimental requirements.…”