Effect of urea and cellulose on anaerobic fermentation | 尿素和纤维素酶对厌氧发酵的影响

Chinese. 研究尿素和纤维素酶对厌氧发酵产气效果的影响，为解决沼气发酵原料利用率低、实际沼气转化率和沼气产气量低等问题提供科学依据。以鸡粪和玉米秸秆（干物质（TS）质量比为2∶1）为原料，采用自行设计的可控性恒温厌氧发酵装置，控制TS质量分数为8%，温度为（30±1）℃，在厌氧发酵的前期（装料时）、中期（正常发酵15 d时）和末期（正常发酵30 d时）,分别添加尿素和纤维素酶，添加水平均设5，10，15，20 g/kg 4个水平，进行为期46 d的厌氧发酵，研究尿素和纤维素酶不同添加时期及不同添加水平对厌氧发酵产气特性的影响。尿素和纤维素酶的3个不同添加时期对产气量均没有显著影响，各个时期添加均可促进厌氧发酵的进行，提高累积产气量。尿素的最佳添加量为20 g/kg，前期、中期、末期添加20 g/kg尿素可使产气量较未加尿素的对照分别提高23.3%，18.3%和12.4%。纤维素酶的添加量对产气量没有显著影响，较好的添加方法为末期添加10 g/kg，该法可使累积产气量较未加纤维素酶的对照提高16.8%。添加尿素和纤维素酶均可促进厌氧发酵的进行，提高产气速率，添加尿素的效果更明显。

English. The research studies the effect of urea and cellulose on biogas yields, which provides a scientific basis for solvting inadequate utilization of raw material in the methane fermentation the actual low rate of mathane conversion and low mathane biogas production, ect. A batch of experiments under the condition of 8% mass fraction of total solid were conducted in a self-manufactured anaerobic fermentation reactor at the temperature of （30±1）℃, with chicken feces and corn stalks (dry mass ratio of 2∶1) as raw materials, adding 5, 10, 15 and 20 g/kg urea and cellulose in early (when loading), medium (normal fermentation by adding 15 days) and late period (30 days to join the normal fermentation); anaerobic fermentation was condusted for 46 days to study the effect of different adding time and levels of area and cellulose on the anaerobic fermentation. The impact of urea and cellulose on biogas gas production showed no significant difference between different periods. Adding urea in the three different periods can promote the anaerobic fermentation, increase biogas production. The best amount of urea is 20 g/kg, in the early, middle, late period, compared with control, the biogas production can increase 23.3%, 18.3% and 12.4% respectively. There is no significant impact of cellulose on biogas production. The better cellulose condition is to add 10 g/kg in the late period. The cumulative biogas production volume is increased by 16.8% compared with control. Added urea and cellulose all can promote anaerobic fermentation, increase biogas production. Add urea is better than cellulose on promoting biogas pruduction, and a reasonable amount can increase gas production.