底物浓度对产甲烷菌群产气性能的影响

试验设置6种不同TS浓度(2%、4%、6%、8%、10%、12%)的牛粪发酵液,在保持相同的恒温条件下,对比各处理在发酵过程中的产气量,沼气中CH4含量,pH变化情况。结果表明:发酵浓度不同,甲烷的产量也不同,以TS 6%、8%最高,10%、12%次之,4%、2%和CK较低,但是各处理产气高峰出现的时期相同。在相同的发酵温度条件下,沼气中的CH4含量与发酵浓度有关,牛粪料液浓度越高沼气中的CH4含量越高,试验的6种发酵浓度,以TS 12%的处理CH4含量最高,平均可达50%以上。发酵浓度不同的牛粪发酵料液在启动发酵初期,pH均下降,然后上升,后期又趋于稳定,发酵浓度越大,越易发生酸化。

Effect of Fermentation Concentrations on the Efficiency of Methanogenic Bacteria

Six different fermentation concentrations （TS concentration of 2% ,4% ,6% ,8% ,10% ,12%） of cow dung were tested in this study under the same temperature condition. Changes of the pH, CH4 content in the biogas gas under different concentrations were compared. It showed that： biogas production was different because of different fermentation concentration, with the highest of TS 6 %, 8%;10 %, 12 % were second; 4%, 2% ,CK were the lowest. However, the all treatments of the highest gas production present at the same peri- od. The content of CH4 concentration was associated with fermentation concentration under the same temperature condition. The higher concentration of cow dung the higher content of CH4, the highest is TS 12% which reach more than 50%. In all treatments, pH was decreased in different levels at very starting period and then increased gradually and then went stable, the more fermentation concentration the easier acidification.