摘要
通过模拟长期稳定运行的厨余垃圾厌氧消化产甲烷反应器和产酸反应器,研究高含固条件(10%TS)下2种反应器中VFAs的产生和转化途径及其对沼气产生的影响。在启动阶段,由于发酵类型不同,2种反应器中VFAs的组成存在较大差异。产酸反应器中,较高的氢分压和丁酸的积累表明该产酸类型以丁酸型发酵为主,基于此,VFAs产量迅速上升,pH迅速降低至5.3左右,CH4产率降低;当产酸反应器结束运行时,TVFA/SCOD稳定在85%以上。相反,在正常的产甲烷反应器中,前期产酸阶段有机物水解产酸的主要途径为丙酸型发酵,氢分压很低。在此条件下,丙酸和丁酸会被转化为乙酸,随之被嗜乙酸产甲烷菌利用,同时,VFAs浓度降低,pH迅速恢复至约6.5;长时间稳定运行中,共产生沼气约34 L,CH4体积分数保持在71%~75%。结果表明,丁酸型发酵是厌氧反应器中VFAs积累、pH降低的主要原因,同时,丁酸的形成会对产甲烷菌的代谢造成抑制。
Through the simulation of long-term stable operation of anaerobic digestion methanogenic reactor and acid-producing reactor of kitchen waste,the production and transformation pathways of VFAs,and its effects on methane production in two reactors with high-solid content(10%TS)were studied.At the start-up stage,the composition of VFAs in the two reactors was significantly different due to the different fermentation types.In the acid-producing reactor,the high partial pressure of hydrogen and the accumulation of butyric acid indicated that the acid producing type was mainly butyric fermentation.Based on this,the yield of VFAs increased rapidly,the pH quickly decreased to about 5.3,and the yield of CH4 decreased.When the acid-producing reactor was completed to run,TVFA/SCOD was stable at over 85%.On the contrary,in the normal methanogenic reactor,propionic acid fermentation was the main way of organic hydrolysis to produce acid in the early stage acid production,and the partial pressure of hydrogen was very low.On these conditions,propionic acid and butyric acid were converted to acetic acid,which was then used by aceticlastic methanogens.Meanwhile,the concentration of VFAs decreased and the pH quickly recovered to about 6.5.During the long-term stable operation,a total of 34 L methane was produced,and the volume fraction of CH4 was maintained at 71%~75%.The results showed that the fermentation of butyric acid was the main reason for the accumulation of VFAs and the decrease of pH in the anaerobic reactor,and the formation of butyric acid could inhibit the metabolism of methanogens.
作者
Zafiry Defemur
李明凯
孔鑫
岳秀萍
Zafiry Defemur;Li Mingkai;Kong Xin;Yue Xiuping(College of Environmental Science and Technology,Taiyuan University of Technology,Taiyuan Shanxi 030024)
出处
《环境卫生工程》
2020年第2期59-65,共7页
Environmental Sanitation Engineering
基金
山西省应用基础研究项目(201801D221338)。
关键词
高含固厌氧消化
产酸
产甲烷
丙酸型发酵
丁酸型发酵
high-solid content anaerobic digestion
acid production
methanogenesis
propionic fermentation
butyric fermentation
