生物处理对稻草秸秆厌氧发酵产甲烷的影响及动力学分析

Effect of Biological Treatment on Methane Production by Anaerobic Digestion of Rice Straw and Its Kinetic Analysis

厌氧发酵制沼气是农作物秸秆能源化利用的有效途径,但产气效率低是其规模化应用的制约因素之一。本实验通过外源添加微生物的方式对稻草秸秆进行处理,研究其对厌氧发酵产甲烷的影响,并采用Gompertz模型对发酵过程进行拟合分析。结果表明:生物处理可有效促进稻草秸秆厌氧发酵产甲烷,且复合菌种具有协同促进作用。单种添加纤维素降解菌后,稻秆单位挥发性固体(VS)甲烷产量达203.52~213.52 mL/g,比未添加菌种的对照组提升了0.42%~5.35%;添加复合菌种的甲烷产量达217.33~245.52 mL/g,比对照组提升5.90%~19.64%。动力学分析表明Gompertz模型对稻秆厌氧发酵产甲烷过程拟合效果佳,模型相关系数R2达0.9999,产气预测值与实测值的绝对百分偏差小。研究表明,生物处理是提高稻草秸秆厌氧发酵产气率的有效手段。

Production of biogas by anaerobic digestion is an effective way for the energy utilization of crop straw,but the low efficiency of biogas production is one of the limiting factors for its large-scale application.In this experiment,rice straw was treated by adding microorganisms to study its effect on methane production by anaerobic fermentation,and Gompertz model was used to fit and analyze the fermentation process.The results showed that the biological treatment could effectively promote the anaerobic digestion of rice straw to produce methane,and the composite strains had a synergistic effect.After adding cellulose-degrading bacteria,the methane production of rice straw anaerobic fermentation reached 203.52-213.52 mL/g,which was 0.42%-5.35%higher than that of the control group without adding bacteria.The methane production of the compound bacteria added reached 217.33-245.52 mL/g,5.90%-19.64%higher than that of the control group.The kinetic analysis showed that the Gompertz model had a good fitting effect on the methane production process of rice straw anaerobic fermentation,the correlation coefficient R2 of the model reached 0.9999,and the absolute percentage deviation between the predicted value of methane production and the measured value was small.The research shows that biological treatment is an effective means to improve the gas production rate of straw anaerobic fermentation.