Abstract：Effects of contact ratio of straw and free fermentation liquid on characteristics of anaerobic fermentation were investigated by batch experiment at (37±1)℃. The fermentation liquid (i.e., total solid was 10%) was used as the reflux daily. The solid and liquid phases of the fermentation materials were separated by arranging porous filter plates at different heights of the reactor bottom, which led to the contact ratios of straw and fermentation liquid were 100% (T1)、50% (T2)and 0% (T3), respectively, during the experiment. Results of biogas yield showed that there was no distinct differences of biogas yield and VS content between the three treatments. This indicated that reduction of contact ratio of straw and fermentation liquid had no impact on biogas yield. Reflux of fermentation liquid for the emerged straw could achieve the same effect of mass transfer as the submerged one. This result provides scientific basis for improving the effective fermentation concentration during the anaerobic digestion of straw. The experiment also found that the contact ratio of fermentation liquid to straw was negatively related with the reaction time. This contact ratio became stable after 6-day anaerobic digestion latter, indicating that the actual free fermentation liquid decreased within the whole system. The major reason is that the straw after 6-day fermentation achieved saturation condition (i.e., 16.42% solid content of straw) and had the effects of adsorption and interception. Thus it is suspicious that the method of devotion to the rate of high solid content and the feasibility of adopts the reflux of fermentation liquid could be benefit to straw anaerobic digestion operation. Other experiment should be conducted to study the effects of water adsorption character, filling height and degree of compaction on the change of water retention property. Furthermore, the analysis of solid content of material is necessary to provide support for the parameter optimization during the dry digestion of straws.
杜静, 陈广银, 叶小梅, 付广青, 常志州. 秸秆与游离发酵液接触比例对产沼气特性的影响[J]. 中国环境科学, 2015, 35(3): 811-816.
DU Jing, CHEN Guang-Yin, YE Xiao-Mei, FU Guang-Qing, CHANG Zhi-Zhou. Effects of contact ratio of straw and free fermentation liquid on characteristics of anaerobic fermentation. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(3): 811-816.
