Methane production from food waste via mesophilic anaerobic digestion with ethanol pre-fermentation: Methanogenic pathway and microbial community analyses.

Affiliation

Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China; Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: [Email]

Abstract

To investigate the methanogenic pathway and microbial community in a mesophilic anaerobic digestion (AD) system with food waste (FW) ethanol pre-fermentation (EP), two semi-continuous AD systems were operated by feeding FW with (PSR) and without EP (control). In this study, δ13C-ethanol was supplemented as solo substrate for AD sludge when the reactors operation stabilized to analyze the methanogenic pathways. The results suggested that approximately 59.3% of methane was produced from acetotrophic methanogens, while 40.7% was formed by hydrogenotrophic methanogens in the PSR group. On the other hand, compared with control, methane produced via CO2 reduction pathway was increased by 4.70%. Meanwhile, the composition variations of the microbial community in AD supported the above conclusion, since the relative abundances of Clostridium and Methanobacterium were enhanced by 7.6% and 10.2%, respectively in PSR reactor. These results provided a theoretical basis for AD applications and biogas yield improvements with EP process.

Keywords

Food waste,High-throughput sequencing,Methanogenic pathway,Microbial community,Stable isotope,

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