Pretreatment of poultry manure for efficient biogas production as monosubstrate or co-fermentation with maize silage and corn stover

•Water extraction of raw poultry manure removed a substantial portion of toxic nitrogen compounds.•The treated solid fraction became amenable for AD as monosubstrate without acclimation.•Co-digestion with either maize silage or corn stover facilitated AD.•Sustainable biological methane production was achieved in continuous co-fermentation.

Water extraction of raw chicken manure elevated the carbon-to-nitrogen ratio 2.7-fold, i.e. from 7.48 to 19.81. The treated chicken manure (T-CM) thus became suitable for biogas fermentation as monosubstrate. Improved methane production was achieved in co-fermentations with either maize silage (24% more methane) or corn stover (19% more methane) relative to T-CM monosubstrate. The standardized biogas potential assay indicated that the methane yields varied with the organic loading rate between 160 and 250 mL CH4/g organic total solid (oTS). Co-fermentation with maize silage was sustainable in continuous anaerobic digestion for at least 4 months.

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