Applied biochemistry and biotechnology

Influence of Organic Load on Biohydrogen Production in an AnSBBR Treating Glucose-Based Wastewater.

PMID 25900436


An anaerobic sequencing batch reactor with immobilized biomass (AnSBBR) was applied to the production of biohydrogen treating a glucose-based wastewater. The influence of the applied volumetric organic load was studied by varying the concentration of influent at 3600 and 5250xa0mg chemical oxygen demand (COD) L(-1) and cycle lengths of 4, 3, and 2xa0h resulting in volumetric organic loads of 10.5 to 31.1xa0g CODxa0L(-1). The results revealed system stability in the production of biohydrogen and substrate consumption. The best performance was an organic removal (COD) of 24xa0% and carbohydrate removal (glucose) of 99xa0%. Volumetric and specific molar productivity were 60.9xa0molxa0H2 m(-3)xa0day(-1) and 5.8xa0molxa0H2 kg SVT(-1)xa0day(-1) (biogas containing 40xa0% H2 and no CH4) at 20.0xa0g CODxa0L(-1)xa0day(-1) (5250xa0mg CODxa0L(-1) and 3xa0h). The yield between produced hydrogen and removed organic matter in terms of carbohydrates was 0.94xa0molxa0H2 Mol GLU(-1) (biogas containing 52xa0% H2 and no CH4) at 10.5xa0g CODxa0L(-1)xa0day(-1) (3600xa0mg CODxa0L(-1) and 4xa0h), corresponding to 23 and 47xa0% of the theoretical values of the acetic and butyric acid metabolic routes, respectively. Metabolites present at significant amounts were ethanol, acetic acid, and butyric acid. The conditions with higher influent concentration and intermediate cycle length, and the condition with lower influent concentration and longer cycle showed the best results in terms of productivity and yield, respectively. This indicates that the best productivity tends to occur at higher organic loads, as this parameter involves the biogas production, and the best yield tends to occur at lower and/or intermediate organic loads, as this parameter also involves substrate consumption.