| 摘要: |
| 利用自制的厌氧发酵装置模拟田间厌氧发酵产生物甲烷的条件，通过添加不同量的尿素，研究C/N对水稻秸秆厌氧发酵产生物甲烷和秸秆降解的影响。设置了C/N为15∶1、20∶1、25∶1、30∶1和对照（53∶1）等五个处理，测定各处理的产气量、甲烷含量和秸秆木质纤维素含量。结果表明C/N对厌氧发酵产气进程有一定影响，峰值出现的时间、峰值的大小在不同处理之间均有差异:以C/N为25∶1的处理峰值出现的最早，较对照早5 d出现;以C/N为20∶1的峰值最高，较对照提高了27.55%。C/N对厌氧发酵累积产气量和累积甲烷产量有显著影响，以C/N为20∶1的处理累积产气量（4 235.00 mL）和累积甲烷产量（1526.34mL）最高，相比对照组的累积产气量和累积甲烷产量分别提高了30.78%和51.31%。C/N对水稻秸秆降解也有显著影响。以20∶1和25∶1处理对秸秆降解的效果最好，其中20∶1处理的总降解率、纤维素降解率和半纤维素降解率分别达到了51.33%、55.31%和53.05%，25∶1处理分别为50.00%、53.08%和49.42%。上述结果表明通过添加尿素调节C/N能够提高水稻秸秆厌氧发酵的产生物甲烷效率和促进秸秆降解，以C/N为(20~25)∶1处理的促进效果最好。 |
| 关键词: 厌氧发酵 碳氮比 秸秆降解 水稻秸秆 生物甲烷 |
| DOI：10.14188/j.ajsh.2020.03.012 |
| 分类号:Q815 |
| 基金项目:湖北省科技创新专项重点项目（2016AHB014） |
|
| Effects of carbon nitrogen ratio on methane production and straw degradation in a simulated field anaerobic fermentation system of rice straw |
|
QIN Kai1, CHEN Fangqing1, ZHANG Hang1, HUANG Yongwen2, LIU Yangyun2
|
|
1.Hubei International Scientific and Technological Cooperation Center of Ecological Conservation and Management in Three Gorges Area, China Three Gorges University, Yichang 443002, Hubei, China;2.Hubei Zhengjiang Environmental Science & Technology Co., Ltd, Yichang 443002, Hubei, China
|
| Abstract: |
| In order to uncover the effects of C/N on methane production and straw degradation, an anaerobic fermentation experiment with rice straw and different amounts of urea was carried out using a self-made anaerobic fermentation device to simulate field anaerobic fermentation conditions. Five C/N ratio treatments, including 15∶1, 20∶1, 25∶1, 30∶1 and the control (53∶1), were set up. The gas production, methane content and straw degradation rate were determined. C/N influenced the process of anaerobic fermentation to a certain extent. The time and value of reaction peak differed among treatments. The reaction peak of the 25∶1 treatment appeared earliest, 5 days earlier than that the control. The reaction peak value of the 20∶1 treatment was the highest, which was 27.55% higher than that of the control. C/N had a significant effect on the cumulative gas production and the cumulative methane production in anaerobic fermentation. The cumulative gas production (4 235.00 mL) and the cumulative methane production (1526.34 mL) of the 20∶1 treatment reached the highest, which were 30.78% and 51.31% higher than that of the control, respectively. C/N also had a significant impact on the degradation of rice straw. The treatments of 20∶1 and 25∶ 1 significantly promoted straw degradation. The total degradation rate, cellulose and hemicellulose degradation rate of treatment 20∶1 reached 51.33%, 55.31% and 53.05%, respectively，treatment 25∶1 were 50.00%，53.08% and 49.42%. The above results indicate that the regulation of C/N by adding urea can improve the methane production efficiency and promote the degradation of rice straw, and the treatment of C / N within (20-25)∶1 range has the best promoting effect. |
| Key words: anaerobic fermentation C/N straw degradation rice straw biomethane |
