Key parameters governing biological hydrogen production from benzoate by Rhodopseudomonas capsulata

摘要

Combination of toxic contaminant degradation with hydrogen production has been regarded as a promising but challenging approach in wastewater treatment. In this work, the effects of benzoate concentration, pH and type of nitrogen source on photo-hydrogen production from benzoate by Rhodopseudomonas capsulata were explored. The experimental results show that both benzoate concentration and pH significantly affected the photo-hydrogen production. Taking into account the specific hydrogen production rate and hydrogen yield simultaneously, a benzoate concentration of 5 mM and pH of 7.0 were favorable for hydrogen production by R. capsulata with 0.2 g L~(-1) glutamate as the nitrogen source. To further improve the economic viability of this process, NH_4Cl could be used to replace the expensive glutamate as nitrogen source, and its desired concentration for hydrogen production was in a range of 0.2-0.4 g L~(-1).