在5L厌氧发酵罐内,控制温度为30℃,pH值为6.5,进行为期10d的厌氧发酵产氢实验,对实验过程中液相的pH值、VFA(挥发性脂肪酸)摩尔浓度和COD值进行实时监控分析,并进行纤维素酶活性和氢化酶活性的检测.结果表明,氢气最大体积分数可达到52.3%,氢气最终产率为13.7mL/g.pH值一直下降,最低降至5.46;VFA摩尔浓度基本呈上升趋势,与pH值变化相对应,发酵类型属于丁酸型发酵.COD值呈现先上升后下降的趋势,最高值为4 368mg/L,且最终COD降解率为51.10%.纤维素酶活性在反应第4天出现最高值0.016 9mg/(mL·h),氢化酶活性最高值出现在反应第6天,为0.568mmol H2/(min·mg).
An experiment of hydrogen production through anaerobic fermentation was carried out under the condition of pH 6. 5 lasting for 10 days, with temperature controlled at 30 ℃ in a 5 L anaerobic fermentation tank. The pH value, VFA molar concentration and COD value of the liquid phase during the experiment process were real-time monitored; meanwhile, cellulase activity and hydrogenase activity were monitored. The results show that the maximum volume fraction of hydrogen can reach 52.3% and the final production of hydrogen is 13.7 mL/g; pH value keeps dropping until it reaches the minimum value 5. 46; VFA molar concentration basically tends to increase corresponding to the change of pH value, it belongs to butyric acid- type fermentation; COD value increases first then decreases, with maximum value 4 368 mg/L and the final COD degradation rate is 51.10% ; the highest value 0. 016 9 mg/(mL · h) appears in the fourth day for the active reaction of cellulase while the highest value 0. 568 mmolH2/(min · mg) for the hydrogenase activity appears in the sixth day.