首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Stability in a Denitrifying Fluidized Bed Reactor
Authors:M Gentile  T Yan  S M Tiquia  M W Fields  J Nyman  J Zhou  C S Criddle
Institution:(1) Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA;(2) Environmental Science Division, Oak Ridge National Lab, Oak Ridge, TN, USA;(3) Department of Natural Sciences, The University of Michigan, Dearborn, MI, USA;(4) Department of Microbiology, Miami University, Oxford, OH, USA;(5) Department of Civil and Environmental Engineering, M11 Terman Engineering, 380 Panama Mall, Stanford, CA 94305-4020, USA
Abstract:This study evaluates changes in the microbial community structure and function of a pilot-scale denitrifying fluidized bed reactor during periods of constant operating conditions and periods of perturbation. The perturbations consisted of a shutdown period without feed, two disturbances in which biofilms were mechanically sheared from carrier particles, and a twofold step increase in feed nitrate concentration. In the absence of perturbations, nitrate removal was stable and consistently greater than 99%. The structure and dynamics of the microbial community were studied using cloning and sequencing techniques and terminal restriction fragment length polymorphism (T-RFLP) of the SSU rRNA gene. Under unperturbed operating conditions, stable function was accompanied by high constancy and low variability of community structure with the majority of terminal restriction fragments (T-RFs) appearing throughout operation at consistent relative abundances. Several of the consistently present T-RFs correlated with clone sequences closely related to Acidovorax (98% similarity), Dechloromonas (99% similarity), and Zoogloea (98% similarity), genera recently identified by molecular analyses of similar systems. Significant changes in community structure and function were not observed after the shutdown period. In contrast, following the increase in loading rate and the mechanical disturbances, new T-RFs appeared. After both mechanical disturbances, function and community structure recovered. However, function was much more resilient than community structure. The similarity of response to the mechanical disturbances despite differences in community structure and operating conditions suggests that flexible community structure and potentially the activity of minor members under nonperturbation conditions promotes system recovery.
Keywords:
本文献已被 PubMed SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号