Biofilm Community Dynamics in Bench-Scale Annular Reactors Simulating Arrestment of Chloraminated Drinking Water Nitrification

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• 作者：Vicente Gomez-Alvarez ; Karen A. Schrantz ; Jonathan G. Pressman ; David G. Wahman
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：May 20, 2014
• 年：2014
• 卷：48
• 期：10
• 页码：5448-5457
• 全文大小：509K
• 年卷期：v.48,no.10(May 20, 2014)
• ISSN：1520-5851

文摘

Annular reactors (ARs) were used to study biofilm community succession and provide ecological insight during nitrification arrestment through simultaneously increasing monochloramine (NH₂Cl) and chlorine to nitrogen mass ratios, resulting in four operational periods (I鈥揑V). Analysis of 16S rRNA-encoding gene sequence reads (454-pyrosequencing) examined viable and total biofilm communities and found total samples were representative of the underlying viable community. Bacterial community structure showed dynamic changes corresponding with AR operational parameters. Period I (complete nitrification and no NH₂Cl residual) was dominated by Bradyrhizobium (total cumulative distribution: 38%), while environmental Legionella-like phylotypes peaked (19%) during Period II (complete nitrification and minimal NH₂Cl residual). Nitrospira moscoviensis (nitrite-oxidizing bacteria) was detected in early periods (2%) but decreased to <0.02% in later periods, corresponding to nitrite accumulation. Methylobacterium (19%) and members of Nitrosomonadaceae (42%) dominated Period III (complete ammonia and partial nitrite oxidation and low NH₂Cl residual). An increase in Afipia (haloacetic acid-degrading bacteria) relative abundance (<2% to 42%) occurred during Period IV (minimal nitrification and moderate to high NH₂Cl residual). Microbial community and operational data provided no evidence of taxa-time relationship, but rapid community transitions indicated that the system had experienced ecological regime shifts to alternative stable states.