【作者】 李思蓓；

【导师】 冯炘；

【作者基本信息】 天津理工大学 ， 环境科学， 2011， 硕士

【摘要】 本研究利用化学试剂对玉米秸秆进行预处理,以脱除木质素,提高组分内纤维素含量,从而更好的利用纤维素降解菌群对秸秆纤维素进行生物降解。通过化学预处理试验发现稀NaOH溶液比稀H₂SO₄溶液有更好的秸秆预处理效果。浓度3%的稀NaOH溶液,固液比1:20,温度108¹15℃条件下处理40目玉米秸秆1h,纤维素含量达到69.2%,纤维素提升率为105.71%,木质素脱除率为94.7%。浓度4%的稀NaOH溶液,固液比1:20,温度115¹21℃下处理处理60目玉米秸秆1h,纤维素含量为64.71% ,纤维素提升率为109.08%,木质素脱除率为83.66%。化学预处理试验筛选出的纤维素含量提升率最高试验组预处理后秸秆进入接下来的秸秆纤维素菌群降解试验。通过菌群降解秸秆纤维素产糖试验得出结论:对于40目预处理后秸秆,在25ml-6%体系中接入5#菌群于30℃下降解到第四天,体系内还原性葡萄糖量有最高值,此时产糖率为22.690 mg·g^-1;同温度同体系下,接入6#菌群,到第四天时体系内糖量有最高值,此时产糖率为26.563 mg·g^-1。对于60目预处理后秸秆,在25ml-6%体系中接入5#菌群于30℃下降解到第六天,体系内还原性葡萄糖量有最高值,此时产糖率为30. 935 mg·g^-1;同温度25ml-6%体系下,接入6#菌群,到第二天时体系内糖量有最高值,此时产糖率为30.028 mg·g^-1。在40目秸秆纤维素降解产糖试验中6#菌群降解活性强于5#菌群,而在60目降解试验时情况相反,但两菌群的最适降解温度均为30℃。更多还原

【Abstract】 This research is about the chemical pretreatment of the crop straw and the microbial degradation of straw cellulose, the chemical pretreatment can make lignin remove and improve the cellulose content that in favor of the microbial degradation of the straw cellulose .It’s discovered that the dilute NaOH solution have better pretreatment effect than the dilute H₂SO₄ solution through the chemical pretreatment experiment.The cellulose content of 40 mesh straw can get up to 69.2%, the upgrade rate of cellulose is 105.71% and the lignin removal rate is 94.7% under the pretreatment conditions of the concentration of 3% NaOH solution, the solid-to-liquid ratio of 1:20, the temperature of 108¹15℃and 1 hour.The cellulose content of 60 mesh straw can get up to 64.71%, the upgrade rate of cellulose is 109.08% and the lignin removal rate is 83.66% under the pretreatment conditions of the concentration of 4% NaOH solution, the solid-to-liquid ratio of 1:20, the temperature of 115¹21℃and 1 hour.The straw that there is more cellulose content after chemical pretreatment by the experiment screening is used to the cellulosic flora degradation experiment.The conclusion is produced by the experiment of microbial flora degradation and sugar test.The glucose content of the degradate system have the highest value until the fourth day when the 5# microbial flora inoculated into the 25ml-6% system at 30℃for pretreated straw in 40 mesh, then the sugar yield is 22.690 mg·g^-1.However, the glucose content of the degradate system have the highest value until the fourth day when the 6# microbial flora inoculated under the same conditions for pretreated straw in 40 mesh, then the sugar yield is 26.563 mg·g^-1.The glucose content of the degradate system have the highest value until the sixth day when the 5# microbial flora inoculated into the 25ml-6% system at 30℃for pretreated straw in 60 mesh, then the sugar yield is 30.935 mg·g^-1.However, the glucose content of the degradate system have the highest value until the second day when the 6# microbial flora inoculated under the same conditions for pretreated straw in 60 mesh, then the sugar yield is 30.028 mg·g^-1.The degradability of 6# microbial flora is better than 5# in the 40 mesh straw degradation experiment and sugar test,but the situation is opposite in the 60 mesh straw degradation experiment,however the optimal degradation temperature of two kind of microbial flora is both 30℃.更多还原