Separate production of hydrogen and methane from cassava wastewater with added cassava residue under a thermophilic temperature in relation to digestibility

摘要: Abstract In this research, the separate production of hydrogen (H2) and methane (CH4) from cassava wastewater with added residue was investigated using a two-stage upflow anaerobic sludge blanket (UASB) system under thermophilic temperature (55 °C) in continuous mode operation steady state condition. The UASB operated an optimum chemical oxygen demand (COD) loading rate 10.29 kg/m3d (based on total volume both bioreactors) different concentrations residue. recycle ratio effluent second bioreactor to feed flow fixed at 1:1 (v/v). addition, solution pH first controlled 5.5, while that not controlled. Under concentration 1200 mg/L, produced gas contained 42.3% H2, 55% carbon dioxide (CO2) 2.70% CH4, 70.5% 28% CO2 1.5% H2. Apart high H2 CH4 performance (45.2 150% improvement, respectively, as compared without residue) (1200 mg/L) COD (10.29 kg/m3d) wastewater, degradation cellulose hemicellulose were 41% 22%, for 23% 11%, bioreactor. digestibility higher than mesophilic temperature.