Electrodeposited polyaniline-carbon felt anode promotes electroactive biofilm for the improved energy recovery in microbial fuel cells using phenol containing wastewater

Abstract

In the present study, Polyaniline (PANI)/ Carbon Felt (CF) composite electrodes were developed to be used as an anode in a Microbial Fuel Cell (MFC) for the enrichment of specific electroactive organisms on the anode. Comparative analysis of two approaches of Phenol degradation namely adsorption & biodegradation and for simultaneous generation of bio-electricity. Sulfuric acid-doped PANI was electrochemically synthesized in aqueous medium and deposited in-situ on the carbon felt anode followed by its characterization using SEM, XRD, and CV. To use these in MFC, different concentrations of PANI ranging from 0.25 mg/cm² to 1.25 mg/cm², was deposited onto CF via potentiostatic electrodeposition technique and compared. The morphological analysis using FESEM of the anode revealed homogenous deposition of nanostructured PANI onto the surface of CF. Further characterization of PANI/CF composite shows that PANI has improved the surface area of the anode, thereby, increasing the conductivity of the anode and promoting biofilm attachment to the anode. The PANI/ CF composite anode with loading rate of 1.0 mg/cm² showed the best results with maximum power density of 584.2 mW m^-2 and lowest charge transfer resistance of 49.6 Ω. The reduction of COD and total phenol of wastewater were 73% and 88% respectively. The obtained results from this study show that the power production and efficiency of the MFCs can be improved greatly by using Sulphate containing PANI/ CF composite as an anode material. The CLSM results indicated that PANI facilitates in promoting EAB biofilm which in turn helps in achieving enhanced power output.