Evaluating the performance of coupled MFC-MEC with graphite felt/MWCNTs polyscale electrode in landfill leachate treatment, and bioelectricity and biogas production.

PURPOSE: A bioelectricity producing system was configured by connecting to a microbial electrolysis cell producing hydrogen, in which both systems were without mediator, to treatment the landfill leachate of the and generate bioelectricity and hydrogen.
METHODS: The anode electrode was made with MWCNTs polyscale coating on graphite felt and the cathode electrode with activated carbon coating on carbon cloth. In the MFC-MEC coupled system, the electrodes were connected in series using copper wire. The system was set up in a fed-batch mode and the landfill synthetic leachate was injected into the anode MFC-MEC chamber as fuel.
RESULTS: In MFC, the highest voltage, current density and power density were 1114 mV, 44.2A/m3 and 49.24 W/m3, respectively. The maximum of the coulombic efficiency system was 94.10%. The highest removed COD, NH4-N and P was 97.38%, 79.56% and 74.61%, respectively. In the MEC, the maximum of voltage input, current density and power density was 1106 mV, 43.88 A/m3and 48.54 W/m3, respectively. The maximum coulombic efficiency system was 125.54%. Also the highest removed COD, NH4-N and P was 97.46%, 78.81% and 76.25%, respectively. The highest biogas production rate and its yield were 39 mL/L.d, and 0.0118 L/g CODrem, respectively.
CONCLUSION: This study found that the MFC-MEC coupled system had promising potential for strong wastewaters treatment, such as the leachate of landfill; and the in-site use of generated electricity and the production of useful fuels such as biogas. © Springer Nature Switzerland AG 2020.