Electricity generation during wastewater treatment: An approach using an AFB-MFC for alcohol distillery wastewater

Abstract

Wastewater is not just waste but could also be sources of energy. Along with many biological approaches, the microbial fuel cell (MFC) has been demonstrated its capability for wastewater treatment and electricity generation. However, the factors, wastewater treatment efficiency, capability of electricity generation and the scaled-up capability, have been limited its application at a large scale. In order to improve the application capacity of the MFC, a system combining an anaerobic fluidized bed (AFB) and a MFC was designed in this study. It was used to treat alcohol distillery wastewater and generate electricity simultaneously. In this study, the COD removal efficiency is from 80–90% in stabilization period. A maximum power density of 124.03mW/m2 was achieved under an external resistance of 120Ω and a variety of system operational settings. Furthermore, a longer hydraulic retention time (HRT) leads to a higher COD removal efficiency. Key factors influencing the electricity generation capacity of the AFB-MFC include the external resistance, the conductivity of the influent, anolyte, and catholyte. These results indicate that the AFB-MFC can be used for electricity generation at a large scale while alcohol distillery wastewater can be efficiently treated under appropriate system operational settings.