Start up of biohydrogen production system and effect of metal ions on hydrogen production

Fermentative hydrogen production is a promising biochemical route to produce renewable H-2. The effect of organic loading rate on the biohydrogen production during the start-up phase and effect of Fe2+ and Mg2+ concentration on biohydrogen production of a continuous stirred tank reactor using molasses wastewater as substrate were investigated. It was found that an initial biomass of 14.07gVSS/L and an organic loading rate of 6.0kgCOD/m(3).d, an equilibrial microbial community in the butyric-type fermentation could be established with in 30 days. It was demonstrated that both Fe2+ and Mg2+ were able to enhance the hydrogen production capacity of microorganism flora. Different concentration of Fe2+ was added to the biohydrogen producing system(50mg/L, 100 mg/L, 200 mg/L and 500 mg/L), the maximum biogas production yield of 6.78L/d and the maximum specific hydrogen production rate of 10.1ml/gVSS.h were obtained at Fe2+ concentration of 500mg/L and 200mg/L, respectively. The maximum biogas production yield of 6.84L/d and the maximum specific hydrogen production rate of 10.2ml/gVSS. h were obtained at Mg2+ concentration of 100mg/L and 50mg/L, respectively.