Magnetite as a means to enhance anaerobic digestion of furfural

Conductive materials may boost the anaerobic digestion of thermal pretreated biomass by overcoming the inhibition effect from by-products generated during the thermochemical pretreatments . The purpose of this study was to explore the influence of magnetite on the anaerobic digestion of furfural, which is found in most biomass hydrolysates . When adding 10 g/l magnetite , the methane yield was enhanced by 125% in comparison to the control. Cyclic voltammetry analysis suggested that the electroactive aggregates were formed after magnetite was added. The microbial community results showed that the Sedimentibacter was significantly enriched (0.2%–18.8%) in the magnetite addition trails; meanwhile, the relative abundance of Methanosaeta was increased by 22.9% compared with the control. Magnetite-amended group of 10 g/l had the lowest hydrogenotrophic methanogens abundance (5.6%) but the highest electrotrophic methanogens abundance (85.3%) than other groups. The energy production efficiency in 10 g/l magnetite addition was 2.3 times higher than that of the control. These evidences indicated that the direct interspecies electron transfer pathway in furfural digestion may be established between Sedimentibacter and Methanosaeta in the presence of magnetite.