Abstract:

In order to study the effect of fulvic acid on peat biomethanation and produce more methane from peat， different contents of fulvic acid were added into the fermentation system of peat biomethanation， including 0 （CK）， 5 （T5）， 10 （T10）， 50 （T50） and 100 mg·L^-1 （T100）. The total gas production， daily gas production， reducing sugar content， volatile fatty acid （VFA） content and pH were determined during the 43 d fermentation process. The results showed that the total methane production of CK was 16.57 mL·g^-1， and the total gas productions of T5， T10， T50 and T100 treatment groups were 21.23、15.55、15.30、11.45 mL·g^-1， respectively. Among them， the total methane production of T5 treatment group was the highest， which was 1.28 times of CK. On the 8^th and 9^th day， the gas production of different fermentation groups reached the peak， and the T5 group reached the peak gas production of 1.81 mL·g^-1 on the 9 th day， which was 1.70 times that of the CK group. The addition of fulvic acid could promote the degradation of reducing sugar and VFA， and at the same time， the pH of the fermentation system should be suitable for the survival of methanogens. These results showed that the water-soluble fulvic acid in peat’s own component humic acid had a significant promoting effect on peat methane production.

Key words: peat, biomethane, fulvic acid, reducing sugar, volatile fatty acid

摘要：

为研究泥炭自有成分黄腐植酸对泥炭产甲烷的影响，提升甲烷产量，在草本泥炭产甲烷发酵反应系统中分别加入0（CK）、5（T5）、10（T10）、50（T50）和100 mg·L^-1（T100）黄腐植酸，分析为期43 d发酵反应过程中的总产气量、日产气量、还原糖含量、挥发性脂肪酸（volatile fatty acids，VFA）含量和pH的变化规律。结果表明，CK处理的甲烷总产量为16.57 mL·g^-1，T5、T10、T50、T100处理的总产气量分别为21.23、15.55、15.30、11.45 mL·g^-1，其中T5处理的甲烷总产量最高，为CK的1.28倍。各发酵组均于第8或第9天达到产气峰值，其中T5处理在第9天达到1.81 mL·g^-1的产气量最高峰，是CK处理的1.70倍。且添加黄腐植酸可促进还原糖和VFA降解，同时使发酵系统的pH更适于产甲烷菌生存。综上所述，泥炭自有成分腐植酸中可溶于水的黄腐植酸对泥炭产甲烷具有显著促进作用。

关键词: 泥炭, 生物甲烷, 黄腐植酸, 还原糖, 挥发性脂肪酸