Performance of stacked microbial fuel cells with barley-shochu waste

Abstract

The treatment of barley-shochu waste combined with electricity generation was examined using stacked microbial fuel cells (SMFCs). The maximum chemical oxygen demand (COD_Cr) removal efficiency and maximum power density were achieved at 36.7 ± 1.1% and 4.3 ± 0.2 W m⁻³ (15.7 ± 0.9 mW m^-2). The acetic acid concentration in effluent increased, whereas the citric acid, ethanol and sugar concentrations decreased during the operation. Microbial community analysis of the anode cell suspension and raw barley-shochu waste revealed that Clostridiaceae, Acetobacteraceae, and Enterobacteriaceae became predominant after the operation, implying that microorganisms belonging to these families might be involved in organic waste decomposition and electricity generation in the SMFCs.

Keywords: Acetobacteraceae; Clostridiaceae; Microbial community; Microbial fuel cell; Shochu waste; Wastewater treatment.