提高沼气产量的外源添加物筛选研究

目前,大部分农村沼气池存在着沼气产量不高的问题,而一些外源添加物可以通过加速厌氧发酵的水解速率或刺激产甲烷菌的新陈代谢过程提高沼气产量.该文分别以猪粪和产甲烷培养基为底物进行厌氧发酵,筛选出能提高沼气产量的外源添加物,并将其进行优化组合,得出最佳用量.试验结果表明:以猪粪为底物进行发酵时,添加啤酒糟能促进底物水解、提高产气量,前4 d的池容产气率比对照高23.17%;以产甲烷培养基为底物时,蛋白胨氨基酸等混合物(物质M)和微量元素液Ⅱ均可刺激产甲烷菌代谢、促进产气,发酵第23 d的累计产气量分别比对照高51.02%和13.37%;随后将筛选出的三种外源添加物进行以猪粪为底物的正交及验证试验,综合考虑促气效果及经济性得出最优组合为微量元素液Ⅱ 10 mL/L,啤酒糟2.5 g/L,物质M 0.05 g/L,该组合在沼气池试验中能提高28.46%的产气量.该试验结果为一种沼气促进剂的研制奠定基础.

Selection of combined additives for enhancing biogas production in anaerobic digestion

In China, the problem of low biogas production exists in many digesters. But some additives could enhance the biogas production by accelerating the process of hydrolysis or methanogenesis in anaerobic digestion. In this research, different kinds of these additives were selected, and then the selected additives were combined optimally to gain a positive impact on the gas production. Swine manure and methanogenic medium were used as the selective substrates, respectively. The results showed that, beer lees could activate the hydrolysis and the gas production rate was 23.17% higher than the control in the first four days, furthermore, in methanogenic medium experiment, both substrate M and trace elements two could promote the metabolism of methanogenic bacteria, which increased by 51.02% and 13.37% in biogas production over the control in 23 days digestion, respectively. Last, the the optimal combinations obtained in orthogonal experiment were trace elements two 10 mL/L, beer lees 2.5 g/L and substrate M 0.05 g/L, which led to 28.46% increase in biogas production in the household digester experiment. This research has provided a useful reference for developing a new type of biogas accelerator.