Two-phase anaerobic digestion of municipal solid wastes enhanced by hydrothermal pretreatment: Viability, performance and microbial community evaluation

摘要: Abstract The viability of hydrothermal pretreatment (HTP) to improve the efficiency biogas production from municipal solid wastes (MSWs) is uncertain because there always a trade-off between organic matters hydrolysis and recalcitrant melanoidins formation when applying HTP on different wastes. In this study, MSWs including waste activated sludge, fruit vegetable residues, kitchen wastes, with without were digested in one phase two-phase anaerobic digesters, respectively. Although specific digestion was significantly enhanced by HTP, no benefit could be found one-phase formation. hydrothermally pretreated much higher (0.71 L biogas/g VSadded) than that or (0.53 L 0.55 L biogas/g VSadded) butyric acid type fermentation dominated acidogenic phase. These findings indicated formed process probably removed digester. Differing previous mixed-acid fermentation, rather ethanol observed digester fed feedstock pH adjusted range 4.0–4.5 high oxidation reduction potential values 49–97 mV. succeeding only 0.59 L biogas/g VSadded, which lower feedstock. Microbial community structure independent substrate-specific digesters. substrate, phylum Firmicutes Bacteroidetes increased, thereby possibly resulting increased content soluble sugar proteins Energy balance estimation four defined scenarios combined AD treatment can achieve net energy output 50.5–97.4% compared other three scenarios. This enables promising alternative way rich protein sugar.