氮磷复合肥投加量对厌氧生物制氢发酵类型的影响

采用连续流厌氧产氢发酵反应器研究了氮磷复合肥对厌氧生物制氢产酸发酵类型的影响。试验过程中有机负荷保持不变(21.8 kgCOD/m3.d),复合氮磷肥投加量从高到低先后为40、20、10和0 mg/L进行变化,试验开始20 d后反应器的发酵类型就从原先的丁酸型转变为乙醇型,在此期间气体的总产量变化不大,但氢气含量和产量明显上升。结果表明,营养元素是厌氧发酵法生物制氢反应器运行过程中影响产酸发酵类型的重要因素,投加氮磷复合肥达到10 mg/L就足以影响发酵类型稳定性,高于10 mg/L时易于形成丁酸型发酵,低于10 mg/L时易于形成乙醇型发酵;营养物质的投加量对于系统的pH和ORP值没有明显影响;在生物制氢反应器中,尽管特定微生物群落是形成特殊产酸发酵类型如丁酸型或乙醇型的前提条件,但其它生态因子如营养元素等对于发酵类型的最终形成也具有重要的影响。

Effect of Compund Fertilizer on Anaerobic Fermentation Types in Hydrogen Bio production Reactor

Effect of compund fertilizer (nitrogen, phosphor) on anaerobic fermentation types in hydrogen bioproduction (HBP) from CST reactor was studied. The organic load rate (OLD) was maintained at 21.8 kg COD/m3·d during the experiments. The compound fertilizer of N/P dosing were 40, 20, 10 and 0 mg/L,respectively. After 20 days operation, the fermentation type was converted from butyric type to ethanol type. During the period, the biogas production kept steady, while hydrogen yield was increased. The results indicated that nutrition was one of the most important factors which affected the fermentation types. In the experiments, adding N,P-compound fertilizer more than 10 mg/L conduce to the establishment of butyric type fermentation, lower than 10 mg/L, the ethanol type fermentation would come into being. The ORP and pH was not affected obviously by the nutrition dosage. In the HBP reactor, special microbe was the precondition of the fermentation type, but the other factors such as nutrition also have significant effects on the formation of ethanol type fermentation.