不同氮源对常中温条件下麦秆厌氧发酵的影响

通过自行设计的厌氧发酵装置,研究不同氮源对常温（20℃）和中温（35℃）条件下麦秆厌氧发酵的影响。结果表明,在常温和中温条件下进行麦秆沼气厌氧发酵时,适量添加外部氮源可加快产气速率,增加产气量,缩短产气停滞时间,其中添加牛粪效果最好,分别在182 d和84 d时发酵完全,总累积产气3 486.80 mL和4 210.70 mL,干物质累积产气量为217.93 mL/g和263.17 mL/g,且在实验期间未出现产气停滞。添加尿素处理次之,分别在累积产气215.70 mL和238.00 mL时进入61 d和20 d的产气停滞期,在196 d和143 d时发酵完全,在实验结束时,累积产气2 784.20 mL和3 454.00 mL,干物质累积产气量为174.01 mL/g和215.88 mL/g。可见,在以秸秆为原料的沼气发酵过程中,可通过添加适量的外部氮源和提高发酵温度来提高沼气产量,而且在条件允许的情况下,应尽量添加畜禽粪便等有机氮源。

Effects of different nitrogen sources on anaerobic fermentation of wheat straw at normal and mesophilic temperatures

Effects of different nitrogen sources on anaerobic fermentation of wheat straw at normal and mesophilic temperatures（20℃ and 35℃） were studied using the ＂system of anaerobic fermentation technology＂ designed by us.The results showed that appropriately added nitrogen sources promotes the rate of biogas production and cumulative biogas yields and shorten stay time of biogas production under anaerobic fermentation of wheat straw at 20℃ and 35℃.The cattle manure was the most effective and cumulative biogas yields were 3 486.80 and 4 210.70 mL,and cumulative biogas yields of dry matter were 217.93 and 263.17 mL / g at 182,84 days,respectively.And the stay phenomenon of biogas production was not appeared during the experiments.The urea was the more effective and stay time of biogas production were 61 and 20 days when cumulative biogas yields were 215.70 and 238.00 mL respectively.And cumulative biogas yields were 2 784.20 and 3 454.00 mL,and cumulative biogas yields of dry matter were 174.01 and 215.88 mL / g at 196,143 days,respectively.Therefore,cumulative biogas yields were enhanced when appropriately added nitrogen sources and raise fermentation temperature during the process of biogas fermentation with wheat straw as raw materials.We should try to add livestock manure and other organic nitrogen sources under the conditions permitting.