Patel Ajay, Nakhla George, Zhu Jingxu
Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Ontario, Canada.
Biotechnol Bioeng. 2005 Nov 20;92(4):427-37. doi: 10.1002/bit.20603.
In this study, the detachment rates of various microbial species from the aerobic and anoxic biofilms in a circulating fluidized bed bioreactor (CFBB) with two entirely separate aerobic and anoxic beds were investigated. Overall detachment rate coefficients for biomass, determined on the basis of volatile suspended solids (VSS), glucose and protein as well as for specific microbial groups, i.e., for nitrifiers, denitrifiers, and phosphorous accumulating organisms (PAOs), were established. Biomass detachment rates were found to increase with biomass attachment on carrier media in both beds. The detachment rate coefficients based on VSS were significantly affected by shear stress, whereas for protein, glucose and specific microbial groups, no significant effect of shear stress was observed. High detachment rates were observed for the more porous biofilm structure. The presence of nitrifiers in the anoxic biofilm and denitrifiers in the aerobic biofilm was established by the specific activity measurements. Detachment rates of PAOs in aerobic and anoxic biofilms were evaluated.
在本研究中，对具有两个完全独立的好氧床和缺氧床的循环流化床生物反应器（CFBB）中，各种微生物从好氧和缺氧生物膜上的脱落率进行了研究。基于挥发性悬浮固体（VSS）、葡萄糖和蛋白质确定了生物量的总体脱落率系数，以及特定微生物群体（即硝化菌、反硝化菌和聚磷菌（PAO））的脱落率系数。发现两个床层中生物量的脱落率均随载体介质上生物量的附着而增加。基于VSS的脱落率系数受剪切应力的显著影响，而对于蛋白质、葡萄糖和特定微生物群体，未观察到剪切应力的显著影响。对于多孔性更高的生物膜结构，观察到较高的脱落率。通过比活性测量确定了缺氧生物膜中硝化菌的存在以及好氧生物膜中反硝化菌的存在。评估了好氧和缺氧生物膜中PAO的脱落率。
