Usually, large quantities of waste water are generated in bio-hydrogen production process because of using low concentration substrate. In order to reduce the discharge of waste water, the effects of substrate concentration on bio-hydrogen production from corn straw were investigated in this paper. The result showed that with the increasing substrate concentration from 20 g ? L-1 to 60 g ? L-1, the hydrogen produced decreased from 104. 0 ml ? (g TS)-1 to 49. 6 ml ? (g TS)-1. While the VFAs (volatile fatty acid) concentration increased sharply from 4705. 23 mg ? L-1 to 9374. 01 mg ? L-1, and the pH of fermentation liquid after hydrogen production decreased from 4. 8 to 4. 2. So, it can be seen that high substrate concentration affected significantly the hydrogen yield of solid state fermentation of corn stalk. To improve potential hydrogen production at higher substrate concentration, the key parameters for bio-hydrogen production at 60 g ? L-1 of corn straw was optimized in a batch fermentation process by investigating effects of the ambient temperature, initial pH and Na2CO3 on the hydrogen yield. The maximum hydrogen yield and rate of hydrogen production were 78. 7 ml ? (g TS)-1 and 2. 3 ml H2 ? (g TS ? H)-1 at initial pH of 8. 0±0.1, temperature of (37±1)℃ and adding Na2CO3 0. 06 g ? (g corn stalk)-1, respectively. The content of H2 was 44. 3%-51. 2 % (vol) and there was no significant methane in the biogas gas.%在发酵生物制氢研究中,通常采用低的底物浓度(≤2.0％),由此产生的大量废水造成严重的二次环境污染问题.为了减少发酵生物产氢过程中废水的产生,以秸秆废弃物为底物,研究了高底物浓度对发酵产氢的影响.结果表明:当底物浓度从20g· L-1上升到60g· L-1时,累积产氢量却从104.0 ml·(g TS)-下降至49.6ml·(g TS)-1.相应地,副产物中挥发性脂肪酸(VFAs)的含量从4705.23mg·L-1快速增加到9374.01mg·L-1,反应后的pH也从4.8下降至4.2.为了提高较高浓度下底物(60 g·L-1)的产氢能力,进一步对发酵产氢的关键过程参数进行了优化,包括发酵温度、初始pH和碳酸钠添加量.优化后的氢产量与最大产氢速率分别达到了78.7 ml·(g TS)-1和2.3ml H2·(gTS·h)-1.
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