不同阴离子在生物质发酵产氢中的作用研究

Effect of anions on hydrogen fermentation in a mixed anaerobic culture system

为揭示不同阴离子在生物质发酵产氢中的作用规律,以混合菌群发酵产氢为研究对象,采用正交试验设计的方法考察了6种不同的阴离子及添加尿素对发酵产氢过程的影响.通过对不同阴离子浓度及相互关系对发酵产氢的影响的综合比较,获得以下结论:促进混合菌群发酵产氢的阴离子组成为:SO24-1.5 g.L-1,Cl-0 g.L-1,NO3-0 g.L-1,Mo7O264-0.1 g.L-1,C2O42-1 g.L-1,C6H5O37-5 g.L-1,(H2N)2CO0 g.L-1;以PDB(马铃薯水解液)为基质发酵原料,H2最高含量和平均含量分别比对照组提高了21.4%和24.1%;平均产氢速率由对照组的36.79 mL.L-.1h-1提高到96.25 mL.L-.1h-1;氢气产率由对照组的0.76 mol.mol-1提高到1.17 mol.mol-1.研究同时证明,尿素对H2的产生具有显著的抑制作用,Mo7O624-则可促进混合微生物对原料的利用和转化;阴离子C2O24-和C6H5O37-的交互作用显著,说明两者同时使用可改善发酵产氢.从理论上对上述结果进行了分析探讨.

In the present study, an L27 （313） orthogonal test was performed in order to investigate the individual and interactive effects of six anions and urea on biohydrogen production in a mixed anaerobic cultures system. Certain components were found to promote hydrogen production, including SO4^2- 1. 5 g L^ - 1, Cl^ - 0 g^ - 1, NO3^- 0 g^ - 1, Mo7 O24^6- 0. 1 g^ - 1, C2 O4^2 - 1 g· L^ - 1, C6 H5 O7^3 - 5 g· L^ - 1, and （ H2 N ） 2 COO g· L^ - 1. Verification experiments demonstrated that the maximal and the average hydrogen content in the mixed anaerobic cultures increased by 21.4% and 24.1% in presence of the above components. The average hydrogen generation rate and hydrogen yield increased from 36.79 mL· L^ - 1· h^ - 1 to 96.25 mL· L^ - 1· h^ - 1 and from 0.76 mol· mol^-1 to 1. 17 mol · mol^-1 , respectively. The results also showed that urea significantly inhibited hydrogen generation, while Mo7 064- enhanced the sugar digestibility of the anaerobic microorganisms. Interestingly, the interactive effect of C2 02- and C6 H5 O7^3 - improved hydrogen production. Finally, the possible mechanisms underlying the interactive effects of these anions and urea are discussed.