发酵生物制氢反应器的产氢菌生物强化作用研究

Bioaugmentation of Hydrogen Producing Bacteria on Operation of Bio-hydrogen Producing Reactor

将发酵产氢菌Ethanoligenens sp．B49投加到连续流搅拌槽式反应器（CSTR）的活性污泥中，以糖蜜废水为底物，进行强化活性污泥产氢效能的研究．对生物强化前和生物强化后反应系统的产氢能力、发酵产物组成和pH值进行了对比分析．结果表明，在COD容积负荷为12kg／（m^3·d）条件下，投加产氢菌可显著提高反应系统的产氢能力并改善发酵产物组成．反应系统的比产氢速率从强化前的3．6mmol／（kg·d）提高到强化后的5．7mmol／（kg·d），是生物强化前的1．5倍．生物强化前，反应系统液相发酵产物乙醇、乙酸和丙酸的平均浓度分别为6．8、5．3和4．8mmol／L，生物强化后乙醇、乙酸和丙酸的平均浓度分别为10．5、7．5和1．7mmol／L，其中乙醇型发酵目的产物乙醇和乙酸在总发酵产物中的比例从生物强化前的72．0％提高为强化后的86．8％．生物强化作用使出水pH值从4．5～4．7下降为4．3．产氢菌的生物强化作用有助于反应器在低负荷运行期迅速形成产氢能力较高的乙醇型发酵．

Hydrogen producing strain Ethanoligenens sp. B49 was inoculated into activated sludge of continuous stirred tank reactor（CSTR） to bioaugment hydrogen production. Hydrogen production capacities, compositions of fermentation products and pH value before and after bioaugmentation were investigated. When organic loading rate was 12 kg/（m^3·d）, bioaugmentation of hydrogen producing strain enhanced hydrogen production rate and improved the composition of fermentation products significantly. After bioaugmentation, hydrogen production rate increased from 3.6 mmol/（ kg· d） to 5.7 mmol/（ kg·d）, which was 1.5 times as that before bioaugmentation. Before bioaugmentation, average concentration of ethanol, acetic acid and propionic acid were 6.8 mmol/L, 5.3 mmol/L, 4.8 mmol/L respectively, while after bioaugmentation, those were 10.5 mmol/L,7.5 mmol/L and 1.7 mmol/L respectively. Ethanol and acetic acid accounted for 86.8% in total fermentative products after bioaugmentation, while only 72 % before bioaugmentation, pH value of effluent dropped from 4.5 - 4.7 to 4.3. Bioaugmentation of hydrogen producing strain is helpful to promote the formation of ethanol-type fermentation in low organic loading rate.