二相UASB工艺微生物生态学的研究

A STUDY ON MICROBIAL ECOLOGY OF TWOPHASE PROCESS FOR UASB REACTOR

采用Hungate严格厌氧操作技术,以人工葡萄糖配水为基质,对二相UASB,工艺的微生物生态学特性进行了初步研究。产酸相中,发酵细菌占优势,达10~7个/ml,比产氢产乙酸细菌和产甲烷细菌高2～3个数量级。产甲烷相中,发酵细菌,产氢产乙酸细菌和产甲烷细菌含量相差不大(约10~8个/ml),因此,产甲烷相的建立依赖于三大类微生物类群的良好代谢平衡。与对照的单相UASB反应器相比,二相UASB工艺的产甲烷相反应器产氢产乙酸细菌量较高,发酵细菌量较低,产甲烷细菌量则非常接近。这种细菌生态分布的差异,可能是导致反应器运行稳定性不同的原因之一。

Using Hungate obligate anaerobic technipue, the characteristics on microbial ecology of twophase anaerobic digestion process for UASB reactors have been investigated with synthetic wastewater of crude glucose as substrate. In acid phase, fermentative bacteria are Predominant, which reach 10~7 cells/ml, 2—3 orders of magnitude greater than H_2—producing acetogenic bacteria and methanogenic bacteria. In methanogenic phase, the numbers of three groups bacteria above are nearly the same (approximately 10~8 cells/ml), which imply that the establishment of methanogenic phase depends on the growth and metabolic balance among fermentative bacteria. H_2—producing acetogenic bactera and methanogenic bacteria. Compared with the bacterial population existed in single phase process of UASB reactor as reference, the H_2—Producing acetogenic bacteria in methanogenic phase of two phase system are more than the former, which is opposite for fermentative bacteria, and the methanogens between the both reactors exhibit no significant change. This difference of microbial ecology may be one of the factor causing the both reactors to have the different operational stability to shocks of organic loading.