Enhanced hydrogen production from corn starch wastewater as nitrogen source by mixed cultures

•Production of hydrogen by mixed-culture fermentation using corn starch wastewaters (CSW) as substrate was investigated.•Carbon-to-nitrogen ratios (C/N), initial substrate loadings and different nitrogen sources were studied.•The optimum initial C/N ratio and total sugar concentration was 9.1 and 10.0 g/L when using CSW as substrate.•The maximum hydrogen yield of 1.88 mol H2/mol glucose consumed was obtained.

The feasibility of hydrogen production from mixed corn starch wastewaters was investigated to recover energy from the treatment of corn starch wastewater. Effects on hydrogen production using peptone, NH4Cl and a mixture of CSL and CGW as nitrogen sources were evaluated with supplement of GW. Experimental results showed that the optimum initial C/N ratio and total sugar concentration was 9.1 and 10.0 g/L respectively with the maximum hydrogen yield of 1.88 mol H2/mol glucose consumed by mixed culture of Bacillus sp. A1 and Brevumdimonas sp. B1. A modified Gompertz equation is able to describe the batch production of hydrogen from wastewater. The maximum hydrogen production rate (Rm) of 165.89 mL/L/h calculated by modified Gompertz equation was obtained using CSL/CGW as nitrogen source, which was 20.8 times higher than that using peptone as nitrogen source. The results revealed an excellent potential for hydrogen production using a mixture of CSL/CGW as a nitrogen source.