Applied Microbiology and Biotechnology

, Volume 61, Issue 5–6, pp 556–561 | Cite as

Elemental compositions and characteristics of aerobic granules cultivated at different substrate N/C ratios

  • Y. LiuEmail author
  • S.-F. Yang
  • J.-H. Tay
Original Paper


The effects of the substrate N/C ratios on the formation, elemental compositions and characteristics of aerobic granules were investigated in four sequencing batch reactors. Results showed that aerobic granules could form at substrate N/C ratios ranging from 5/100 to 30/100 and the substrate N/C ratio had a direct and profound effect on the elemental compositions and characteristics of the aerobic granules. Nitrifying populations in aerobic granules were enriched significantly with the increase in the substrate N/C ratio, while the respective ratio of cell oxygen, nitrogen and calcium to cell carbon were also determined by the substrate N/C ratio. It was found that cell hydrophobicity of aerobic granules was inversely related to the ratio of cell oxygen normalized to cell carbon. Since the cell calcium content in aerobic granules developed at different substrate N/C ratios was even lower than that in the seed sludge, it is reasonable to conclude that the cell calcium would not contribute to aerobic granulation. This study probably for the first time demonstrates that the elemental composition, microbial distribution and characteristics of aerobic granules are related to the substrate N/C ratio applied.


Sludge Chemical Oxygen Demand Sequencing Batch Reactor Upflow Anaerobic Sludge Blanket Nitrify Bacterium 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  1. 1.Environmental Engineering Research Centre, School of Civil and Environmental EngineeringNanyang Technological UniversitySingaporeSingapore

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