Performance of magnetic iron nanoparticle decorated electrodes single chambered MEC fed with combined leachate and dairy industry wastewater

Abstract

Increased human activity and consumption of natural energy resources have led to decline in the stock of fossil fuels. The current technologies used for energy generation are not environment friendly. Microbial electrolysis cell (MEC) represents a new approach for harnessing the energy contained in the organic matter of wastewater. It is a type of bioelectrochemical systems in which chemical energy stored in organic compounds are converted to biogas such as hydrogen through biocatalytic oxidation by microorganisms. But it still suffers from the lack of efficiency in terms of hydrogen production and current generation. Previous studies have demonstrated that the electrodes coated with nanoparticles such as Fe, Au, Pd, and Ni nanoparticles have the potential to enhance energy recovery in MEC. Hence, the present study aims to use single chambered membrane-less microbial electrolysis cell with magnetic iron nanoparticle coated electrodes for treating combined leachate and dairy industry wastewater. The performance of the MEC was assessed through COD removal, current and biogas generation at an applied voltage of 0.8 V and HRT of 48 hours. Results demonstrated that the maximum current density achieved by nanoparticles decorated electrodes was 3.86 times higher than iv generated by plain electrodes. The highest COD removal efficiency of 96.5% was achieved at OLR equal to 17.14 gCOD/L/d. The maximum coulombic efficiency of 155% represents the conversion of maximum chemical energy stored in the combined wastewater into electrical energy. The hydrogen production rate of 3.192 L/L/d was achieved in this study. The results shows that magnetic iron nanoparticle coated electrodes enhance the current generation and COD removal in single chambered MEC operated with combined leachate and dairy wastewater treatment.