Influence of iron species on integrated microbial fuel cell and electro-Fenton process treating landfill leachate

MFC-based bioelectro-Fenton (BEF) system was examined in duplicate to deal with recalcitrant organics of mature landfill leachate pre-treated with partial nitritation-anammox process. The system performance was evaluated at various iron species (iron (II) sulfate and iron (III) chloride) and iron dosages (150, 300 and 500 mg L⁻¹) as Fenton catalyst. A simultaneous anolyte and catholyte COD removal efficiency of 71–76% and 77–81% occurred respectively, having glucose substrate (anolyte) and leachate (catholyte). Upon switching the system to 80% and then 100% real leachate as anolyte substrate affected the COD removal efficiency and CE, but no significant effect was noticed in terms of current density. A maximum current density of 1.7 A m⁻² was obtained throughout the experiment. Iron concentration of 300 mg L⁻¹ proved to be optimum dose; whereas, iron (II) catalyst showed slightly better efficiency than iron (III). The results demonstrated the potential of an MFC based BEF oxidation as sustainable and efficient route for simultaneous anodic and cathodic pollutant removal coupled with power production.