【摘要】 采用半连续试验研究了鸡粪中温干式沼气发酵启动阶段,温度从35℃骤降至15、20、25℃和30℃并再次恢复至35℃过程中,温度变化对产气性能的影响,以期为干式沼气发酵的启动提供科学依据。结果表明:温度变化影响启动阶段沼气产量和甲烷含量,变温期间,15、20、25、30℃和35℃最大容积沼气产率分别为0.017、0.126、0.357、0.442 L·L^-1·d^-1和0.493 L·L^-1·d^-1;最大原料甲烷产率分别为0.011、0.074、0.211、0.261 L CH4·g^-1VS和0.294 L CH4·g^-1VS。对比35℃恒温发酵产气性能,温度骤降至15℃和20℃条件下运行的产气能力明显小于温度骤降至25℃和30℃条件运行的产气能力。温度变化幅度越大,产气性能受影响越大,沼气发酵微生物对一定温度变化范围具有一定的适应性,足够的时间范围内可以顺利恢复。在变温发酵启动过程中,相比脱氢酶,辅酶F₄₂₀浓度变化和甲烷产率之间具有更好的线性相关性。研究表明:鸡粪35℃中温干式沼气发酵可以顺利启动,但温度变化导致厌氧干发酵启动时间延长。辅酶F₄₂₀可以作为反映干式沼气发酵启动阶段污泥活性变化的指标。更多还原

【Abstract】 Semi-continuous experiments were carried out to study the effects of temperature changes on the gas production performance of mesophilic temperature dry biogas fermentation of chicken manure during the start-up phase. The temperature was decreased from 35 ℃ to15, 20, 25 ℃ and 30 ℃, and then returned to 35 ℃ to conduct the start-up test of semi-continuous dry biogas fermentation of chicken manure to provide a scientific basis for the start of dry biogas fermentation. The results showed that the fermentation temperature affected the biogas production yield and methane content at the start-up stage. During the temperature change stage, the maximum biogas production rates at 15, 20, 25, 30 ℃, and 35 ℃ were 0.017, 0.126, 0.357, 0.442 L·L^-1·d^-1, and 0.493 L·L^-1·d^-1, respectively. The maximum methane production rates of raw material were 0.011, 0.074, 0.211, 0.261 L CH4·g^-1 VS, and 0.294 L CH4·g^-1 VS, respectively. Gas production performance of the 25 ℃ and 30 ℃ temperature conditions were more effective than that of the 15 ℃ and 20 ℃ temperature conditions. At startup, gas production yield decreased significantly with temperature changes; the greater the decrease, the greater the impact. The microorganisms used for biogas fermentation had some flexibility regarding temperature changing within a certain range; performance could be successfully restored within enough time, but the time of start-up stage was delayed. Changes in the concentration of dehydrogenase and coenzyme F₄₂₀ reflected the changes in sludge activity during the temperature changes. There was a better linear correlation between coenzyme F₄₂₀ and methane yield. Our results indicated that the dry biogas fermentation of chicken manure at 35 ℃ could be started smoothly, and coenzyme F₄₂₀ could be used as an indicator of sludge activity at the start-up stage of dry biogas fermentation.更多还原