The effect of substrate concentration on biohydrogen production by using kinetic models

The effect of substrate concentration ranging from 0 to 300 g/L on fermentative hydrogen production by mixed cultures was investigated in batch tests using glucose as substrate. The experimental results showed that, at 35 and initial pH 7.0, during the fermentative hydrogen production, the hydrogen °C production potential and hydrogen production rate increased with increasing substrate concentration from 0 to 25 g/L. The maximal hydrogen production potential of 426.8 mL and maximal hydrogen production rate of 15.1 mL/h were obtained at the substrate concentration of 25 g/L. The maximal hydrogen yield and the maximal substrate degradation efficiency were respectively 384.3 mL/g glucose and 97.6%, at the substrate concentration of 2 g/L. The modified Logistic model could be used to describe the progress of cumulative hydrogen production in this study successfully. The Han-Levenspiel model could be used to describe the effect of substrate concentration on fermentative hydrogen production rate. Supported by the National Natural Science Foundation of China (Grant No. 50325824)