Hydrogen and methane production by co-digesting liquid swine manure and brewery wastewater in a two-phase system

Co-digesting liquid swine manure and brewery wastewater for hydrogen and methane production was studied using an integrated, two-phase system with different organic loading rates (OLR) under mesophilic conditions. The highest volumetric hydrogen and methane production rates achieved were 294.06 ± 3.06 mL H₂ L^-1 d^-1 and 497.94 ± 10.01 mL CH₄ L^-1 d^-1, respectively, at the OLR of 8613.6 mg COD L^-1 d^-1, together with the highest hydrogen-COD and -TVS yields (34.14 ± 0.36 mL g^-1 COD and 45.46 ± 0.71 mL g^-1 TVS) and the maximum methane-TVS yield (261.42 ± 8.41 mL g^-1 TVS). The highest hydrogen and methane concentrations in the biogas (31.86 ± 0.68% and 82.66 ± 0.33%, respectively) were also obtained at this OLR. The maximum methane-COD yield (270.3 ± 3.93 mL g^-1 COD), however, was from the lowest OLR (1148.6 mg COD L^-1 d^-1). The two-phase system removed 75.54 ± 0.19% of COD from the influent.