Meiling Chi, Huanhuan He, Hongyu Wang, Minghua Zhou and Tingyue Gu
Microbial Fuel Cells (MFCs) have emerged as a potential technology for direct bioelectricity production from organic matters in wastewater streams that are otherwise unutilized. The graphite felt anode modification by nanopolypyrrole (nano-PPy) was carried out via electropolymerization reaction using cyclic voltammetry (CV). The electropolymerization trials designated PPy-1, PPy-2 and PPy-3 used 5, 10 and 20 CV cycles, respectively with a scanning voltage ranged from 0 to 0.9 V at a rate of 50 mV/s. The influences of reaction time (reflected by the number of cycles of CV) on the morphology of the polypyrrole films on the anodes and the MFC performance were investigated. The polypyrrole film thickness and particle diameter increased with reaction time. Using the PPy-2 anode, the maximum power density was 430 mW/m2, a 15% increase compared with that of the control (i.e., MFC with an unmodified anode). Furthermore, the Coulombic efficiency and Chemical Oxygen Demand (COD) removal also increased after the anode modification.