外源氮元素添加对醋糟厌氧发酵产氢的影响

Effects of nitrogen sources addition on anaerobic digestion process of vinegar residue

在中温条件下,采用批式发酵方式,探讨外源氮元素添加对醋糟厌氧发酵产氢的影响。以尿素、氯化铵和硝酸钾分别代表有机氮、氨基氮和硝基氮,在确定最佳C/N的条件下,主要研究了氢气产率、厌氧发酵类型以及发酵前后发酵液中氮形态的变化。结果表明,醋糟厌氧发酵产氢的最佳C/N为40,尿素、氯化铵和硝酸钾添加使得氢气产率从54 m L/g-VS提高到65、85和78 m L/g-VS,分别提高了46%、57%和21%。加入氯化铵和尿素可以将发酵类型从丁酸型转化为乙醇型;发酵液中氮的形态以氨态氮为主,外源氮元素添加,使得厌氧发酵后总氮含量均显著增加,硝基氮含量均显著下降。

Effects of nitrogen sources addition on mesophilic anaerobic fermentation of vinegar residue were investigated in batch tests. Urea,NH4 Cl and KNO3 were used as organic,ammonium and nitrate nitrogen respectively.Under the optimum C / N ratio,the variation of hydrogen yield,fermentation style and nitrogen form were studied. Results indicated that the optimum C / N ratio was 40 for vinegar residue fermentation. The hydrogen yield increased from54 m L / g-VS to 65,85 and 78 m L / g-VS by addition of urea,NH4 Cl and KNO3,corresponding to 46%,57% and21%,respectively. The fermentation type was changed from butyrate-type to ethanol-type as a result of NH4 Cl and urea addition. Ammonium was the main form of nitrogen in the fermentation liquid. The total nitrogen increased at the end of fermentation,while the nitrate nitrogen decreased significantly.