Investigating microbial fuel cell aided bio-remediation of mixed phenolic contaminants under oxic and anoxic environments

Abstract

The work focuses on the bioelectrochemical treatment of wastewater containing phenol and trichlorophenol in microbial fuel cells (MFC) with non-coated and PANI/SnO2 modified anodes respectively. The SnO2 and PANI/SnO2 nanocomposite synthesised were characterised using XRD and FTIR techniques. The results reflected that the efficiency of the system performing oxic treatment was better than the system performing anoxic treatment. The anoxic treatment of mixed phenolic contaminant using non-coated and coated electrodes yielded the highest power densities of 375.36 and 454.81 mW/m2 respectively while the maximum power densities under oxic treatment were 464.81 and 522.77 mW/m2 respectively. The consistently higher performance of oxic MFCs in terms of power generation and treatment efficiencies infers its higher potential in treating toxic phenolic contaminants. UV/Vis spectrophotometry and cyclic voltammetry (CV) also confirm better oxic treatment. Moreover, the electrochemical impedance spectroscopy (EIS) data further justified the higher oxic performance with reduced charge transfer and ohmic resistances. The study advocates MFC as a practically feasible alternative in treating recalcitrant chemical wastes with lower energy requirements.