Electricity Generation and Biofilm Formation in Microbial Fuel Cells Using Plate Anodes Constructed from Various Grades of Graphite

Abstract

Construction materials as well as the electrode configuration are major factors affecting electricity generation in microbial fuel cells (MFCs). Three graphite plate electrodes (HK06, G347 and POCO3) with different characteristics (specific resistance, grain size and specific gravity) were used to evaluate electricity generation and biofilm formation in MFCs. The electrodes were assessed by operating duplicate MFCs under the same conditions. Electrochemical impedance spectroscopy, cyclic voltammetry and linear sweep voltammetry were used to evaluate the performance of the electrodes. The data indicated the grade of electrode played a critical role in the MFCs performance. Higher power density was observed for the graphite electrode designated as POCO3. The trend for increasing electricity generation was as follows: POCO3 > G347 > HK06. Distinct microbial populations were detected in the biofilm community when comparing the different electrodes. Selecting electrodes for optimum electricity generation is important in the development of laboratory scale and full-scale MFCs.