不同配比牛粪与农村生活废弃物混合发酵的产气潜力研究

Biogas Production Potential of Cow Dung and Domestic Waste Mixed Fermentation with Different Mixing Ratio

在恒温35℃和发酵液TS为8%的条件下,研究了不同配比(TS质量比分别为1∶9,3∶7,5∶5,7∶3和9∶1)奶牛粪和果蔬废弃物、奶牛粪和餐厨垃圾以及肉牛粪和果蔬废弃物混合发酵的产气效果。结果表明,累计产气量和TS产气量最高的是配比为5∶5的奶牛粪和餐厨垃圾,分别达20702 mL和259 m L·g^(-1),最低的则是配比为3∶7的奶牛粪和餐厨垃圾,分别仅为1173 m L和15 m L·g^(-1)。发酵过程中牛粪与生活废弃物以5∶5,7∶3和9∶1配比混合发酵的pH值均维持在6.0~7.5之间,厌氧发酵累计产气量均较高;而配比为1∶9和3∶7时,发酵过程中pH值几乎均低于5.5,厌氧发酵受到明显抑制。因此,在牛粪与生活废弃物混合发酵时,增加牛粪比例可提高厌氧发酵的累计产气量和发酵液中pH值的稳定性。

Anaerobic co-digestion of cow dung and domestic waste were conducted with 5 mass mixing ratios（ including1∶ 9,3∶ 7,5∶ 5,7∶ 3 and 9∶ 1） under the condition of 35 ℃ and total solid mass fraction（ TS） of 8%. The results indicated that the mixing ratio of 5∶ 5（ cow dung ∶ kitchen waste） obtained the maximum cumulative biogas yield of 20702 m L and maximum TS biogas yield of 259 m L·g-1,while the mixing ratio of 3∶ 7（ cow dung ∶ kitchen waste） obtained the minimum cumulative biogas yield of 1173 m L and minimum TS biogas yield of 15 m L·g-1. The p H were maintained 6. 0 ~ 7. 5 under the cow dung and domestic waste mixing ratios of 5 ∶ 5,7 ∶ 3 and 9 ∶ 1,and their cumulative biogas yields were higher than those of other ratios. The p H were below 5. 5 under the mixing ratios of 1∶ 9 and 3∶ 7 during almost all the fermentation process,and so the anaerobic fermentation was significantly inhibited. These results showed that increasing the proportion of cow dung could improve the anaerobic process when cow dung and domestic waste were digested together.