Long-term evaluation of methane production in a bio-electrochemical anaerobic digestion reactor according to the organic loading rate

摘要

In this study, the effects of differing organic loading rates (OLRs) on methane production were evaluated via long-term operation of a bio-electrochemical anaerobic digestion (BEAD) reactor and an anaerobic digestion (AD) reactor. In the AD reactor, the maximum OLR was 4?kg/m3·d whereas the electro-active microbial community in bulk and on the biofilm of the BEAD reactor produced methane even at 10?kg/m3·d. The BEAD reactor rapidly removed volatile fatty acids (VFAs) and reduced H+to H2at high OLRs, thereby preventing VFA accumulation and pH decrease. After the steady state was achieved, both the AD and BEAD reactors exhibited similar organic matter removal and methane production at a low OLR. Thus, a BEAD reactor can stably produce methane under conditions of high OLR and severe OLR fluctuation and can even shorten the stabilization period over the long term.