对比分析HRT对ACR乙醇型和丁酸型发酵制氢系统的影响

Comparison of the influence of HRT on biohydrogen production from ethanoltype fermentation and butyric-type fermentation in ACR system

以糖蜜废水为基质,采用两套厌氧接触式发酵制氢反应器（ACR）分别在p H为4.5-5.0、5.5-6.0下的启动和运行,以分别考察乙醇型和丁酸型发酵系统在不同水力停留时间（HRT）下的运行特性.结果显示,当进水COD=5000 mg·L-1,HRT从12 h缩短至4 h时,乙醇型发酵制氢系统中的产氢微生物菌属得到不断富集,在HRT=4 h时,系统的产氢速率和污泥比产氢速率分别达到30.1 L·d-1和13.5 mmol·g-1·d-1;而HRT的缩短使得丁酸型发酵系统内生物量减小,导致底物的转化率下降,反应器在HRT为8 h时,系统获得最大产氢速率,为9.3 L·d-1.研究结果也表明,在HRT为4-12 h的运行中,ACR乙醇型发酵系统的产氢效能始终优于丁酸型发酵制氢系统,其单位基质的氢气转化率约为丁酸型发酵的1.5-2.2倍.

The influence of HRT on the performance of hydrogen production with ethanol-type fermentation and butyric-type fermentation in anaerobic contact reactor（ ACR） was compared in this present study. The ethanol-type fermentation and butyric-type fermentation was established by controlled the p H at 4. 5 - 5. 0、5. 5 - 6. 0,respectively. The results showed that hydrogen producing microflor was enriched in ethanol-type fermentation as the HRT was shorted from 12 h to 4 h under constant influent chemical oxygen demand（ COD） 5000 mg·L-（-1）,and the hydrogen production rate and the specific hydrogen production rate of sludge was peaked at 30. 1 L·d-（-1）,13. 5 mmol·g-（-1）·d-（-1）under HRT of 4 h,respectively. Whereas in the butyric-type fermentation system,the biomass concentration was decreased as the HRT was shorted,which induced the substrate degrading efficiency declined,and the hydrogen production rate was climaxed at only 9. 3 L·d-（-1）under HRT of 8 h. This study showed that the hydrogen production capability of ethanol-type fermentation was advantaged over butyric-type fermentation as the HRT of ACR ranged from 4 h to 12 h,and the hydrogen yield of ethanol-type fermentation was 1. 5 - 2. 2 times as that of butyric-type fermentation.