Investigating the role of different materials supplementation in anaerobic digestion of kitchen waste: Performance and microbial community dynamics

Anaerobic digestion (AD) is a promising strategy to achieve both carbon emission reduction and sustainable development. In this work, the performance and microbial community dynamics were investigated in an anaerobic digestion system using four different type of materials. The results obtained indicated that, in the presence of bentonite with the properties of high grease adsorption and alkaline, the improved performances involved in biogas production rate (996.0 mL/g-VSFW) and organic removal efficiencies (84.38%) were higher than that in the presence of biochar. However, activated carbon and zero-valent iron inhibited kitchen waste AD's biogas production rate. Microbial community analysis revealed that the hydrogenotrophic mathanogenesis significantly increased when the additive was fed with kitchen waste digester. Bentonite increased the compo-sition and diversity of archaea and bacteria and enriched Methanolinea and Bathyarchaeia which in turn improved AD performance. Biochar enriched Lentimicrobium capable of electron transfer to conductive material. Together with the increased abundance of Methanobacterium that could proceed direct interspecies electron transfer (DIET), AD was likely improved due to the processing of DIET with adding biochar. In this way, this study was expected to obtain a research basis for evaluating the influence of exogenous additives on kitchen waste AD.

Automated summary

“This study investigated the performance and microbial community dynamics in an anaerobic digestion system using different materials. The results showed that bentonite with high grease adsorption and alkaline properties improved biogas production and organic removal efficiencies. However, activated carbon and zero-valent iron inhibited biogas production from kitchen waste. Microbial community analysis revealed increased hydrogenotrophic methanogenesis with the addition of an additive. Bentonite increased the composition and diversity of archaea and bacteria, while biochar enriched bacteria capable of electron transfer. These findings provide a research basis for evaluating the influence of exogenous additives on kitchen waste anaerobic digestion.”