活性碳对甘蔗糖蜜酒精废水加铁厌氧消化的影响

Effect of Activated Carbon on Iron Added Anaerobic Digestion of Molasses Vinasse

为探究不同铁碳比对糖蜜酒精废水厌氧处理效果的影响,本实验设计了四种添加方式(对照组、Fe、Fe/C=1∶1和Fe/C=1∶2)进行厌氧发酵。结果表明,Fe/C的添加对反应器的甲烷产量和COD去除率并无影响,但显著降低了H_(2)S和H_(2)含量,提高了挥发性脂肪酸含量以及乙酸占比。当Fe∶C添加比为1∶1时,其反应器中挥发性脂肪酸含量由第4 d的1048.98 mg/L上升到第36 d的6477.63 mg/L。细菌群落分析发现,Fe/C的添加导致水解优势菌群出现了由Bacteroidetes-Synergistetes类群转化为Firmicutes-Chloroflexi类群的趋势,适量碳的添加有利于提高菌群的抗逆性。Fe的添加富集了古菌群落Methanobacterium和Methanosarcina;Fe/C的添加也促进了Methanobacterium的富集,但相应的降低了Methanosarcina和Methanosaeta这类甲烷菌的相对丰度。这些菌群的改变使得甲烷菌群由甲基途径转向为乙酸型和氢营养型途径。

To investigate the effect of different Fe/C ratios on the anaerobic digestion of molasses vinasse,four types of additions(control group,Fe,Fe/C=1:1 and Fe/C=1:2)were performed for continuous anaerobic digestion.The results showed that the addition of Fe/C had no significant effect on the methane yield and COD removal rate,but significantly reduced the H_(2)S and H_(2) contents,and increased the volatile fatty acid content and the percentage of acetic acid.When the Fe/C addition ratio was 1:1,the volatile fatty acid increased from 1048.98 mg/L at 4 d to 6477.63 mg/L at 36 d.Bacterial community analysis demonstrated that the addition of Fe/C led to a trend of conversion for the dominant hydrolytic flora from Bacteroidetes-Synergistetes taxa to Firmicutes-Chloroflexi taxa,which improved the reactor resistance.The addition of Fe enriched Archaeal Methanobacterium and Methanosarcina;the addition of Fe/C promoted the abundance of Methanobacterium,but reduced Methanosarcina and Methanosaeta.These changes in the methanogens resulted in a shift from the methyl pathway to the acetate and hydrotropic types.