低温沼气功能菌群的选育与试验

通过低温定向培养,从高纬、高寒野外厌氧环境样品和冬季沼气池底泥样品中分别选育出野生低温功能菌群和沼气池低温菌群。在13℃和10℃低温条件下,野生低温菌群产气率达到0.14 m3/d.m3和0.10 m3/d.m3,但所产沼气的甲烷含量较低,只有51.0%和48.0%。同样温度下,沼气池低温菌群的产气率只有0.06 m3/d.m3和0.04 m3/d.m3,但所产沼气的甲烷含量较高,达到62%和56%。两类菌群混合发酵可显著改善产气性能,相同温度下,产气率可达到0.15 m3/d.m3和0.11 m3/d.m3,高于两类菌群单独发酵,是常温菌群的3倍以上;混合低温菌群所产沼气的甲烷含量为57.0%和52.0%,介于野生低温菌群和沼气池低温菌群之间,比常温菌群提高19.0%和16.0%。研究结果表明,混合低温菌群具有较好的低温产气性能和广阔的应用前景。

Breeding and Testing of Hypothermic Biogas Functional Microflora

Two groups of hypothermic biogas functional microflora were bred from anaerobic environmental and digester samples collected in high latitude and high altitude areas by hypothermic oriented selection.At 13℃ and 10℃,the biogas production rates of the wild low-temperature microflora bred from anaerobic environmental samples were 0.14 m3/d·m3 and 0.10m3/d·m3 respectively,with methane contents of 51% and 48% correspondingly.However,at the same temperatures,the digester low-temperature microflora bred from household biogas digester samples had lower biogas production rates of 0.06 m3/d·m3 and 0.04 m3/d·m3 but higher methane contents of 62.0% and 56.0%.By mixing the two microflora,biogas fermentation was significantly improved with a gas production rate up to 0.15 m3/d·m3(13℃) or 0.11 m3/d·m3(10℃),which was much higher than that in the fermentation by either of the microflora and three times as high as that in the fermentation driven by normal temperature microflora.Biogas produced by mixed microflora contained 57.0%(13℃) or 52.0%(10℃) methane,with methane content higher than the biogas from wild low-temperature microflora,lower than that from digester low-temperature microflora,and 19.0%(13℃) or 16.0%(10℃) higher than that generated by normal temperature microflora.The results show that the mixed low-temperature biogas functional microflora is provided with excellent hypothermic biogas-producing properties and a good application prospect.