Magnetic chicken bone biochar mediated anaerobic co-digestion of lignocellulosic biomass for energy enhancement and microbial synergism.

[Display omitted] • The maximum biogas generation (54.33 %) was attained at 4 g/L magnetic bone biochar. • Volatile solids removal (89.02 %) was achieved at 4 g/L magnetic bone biochar. • Ruminofilibacter abundance was increased in all biochar treated reactors. • Methanosarcina was abundant archaea in magnetic biochar added digesters. This study showed the effects of prepared chicken bone-derived biochar (CB) and magnetic chicken bone-derived biochar (MCB) at various ratio (2–12 g/L) on anaerobic co-digestion (AcoD) of corn straw (CS) and cow dung (CD). The physiochemical characterization of CB, MCB, and lignocellulosic biomass (including CS and CD) was analyzed. Biogas production, kinetics, total solid (TS), volatile solid (VS) removal, and microbial communities were studied. Addition of 4 g/L MCB enhanced the biogas production by 54.33 % along with 75.82 % TS and 89.02 % VS removal. Ruminiclostridium was enhanced by 81.25 % in MCB 4 g/L treated reactor, which degrade cellulose and hemi-cellulose fibers. Methanosarcina involved in the biogas production through hydrogenotrophic and acetoclastic pathways was enriched by 43–61 % in the MCB treated reactors compared to control group. The improvement of biogas production from the lignocellulosic biomass can be improved by the addition of MCB due to facilitation of direct interspecies electron transfer among the microbes in anaerobic digestion. [ABSTRACT FROM AUTHOR]