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Effect of COD/N and COD/P ratios on the PHA transformation and dynamics of microbial community structure in a denitrifying phosphorus removal process

Authors

  • Yayi Wang,

    Corresponding author
    • State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, PR, China
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  • Junjun Geng,

    1. State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, PR, China
    2. Architectural Design & Research Institute of Tongji University (Group) Co., Ltd , Shanghai, 200092, P. R., China
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  • Zhongjia Ren,

    1. State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, PR, China
    2. Shanghai Municipal Engineering Design Institute (Group) Co., Ltd, Shanghai, P. R., China
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  • Gang Guo,

    1. State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, PR, China
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  • Chong Wang,

    1. State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, PR, China
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  • Hong Wang

    1. State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, PR, China
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Correspondence to: Y. Wang, State Key Laboratory of Pollution

Control and Resources Reuse, School of Environmental Science and

Engineering, Tongji University, Siping Road, Shanghai 200092, P. R. China.

E-mail: yayi.wang@tongji.edu.cn

Abstract

Background

A lab-scale anaerobic-anoxic/nitrification (A2N) two-sludge sequencing batch reactor (SBR) system was operated to assess the relationship among intracellular polymer conversions, bacterial population dynamics and nutrient removal performance in response to the varying influent COD/N/P.

Results

Complete nutrient removal was achieved in the A2N-SBR in Run 3 where the COD/P and COD/N were 20.6 and 6.9, respectively. This coincides well with the highest P release/HAc uptake ratio occurring in Run 3, confirming high abundance of denitrifying phosphorus accumulating organisms (DPAOs) in the biomass. Under the stress of N or P limitation, more poly-β-hydroxyalkanoates (PHA) was synthesized, with the increasing proportion of poly-hydroxyvalerate (PHV) in PHA. The population biodiversity decreased with increasing carbon loading when P loads were maintained at constant levels, and recovered to the initial level after P loading decreased.

Conclusions

Increasing COD/P promoted anaerobically synthesized PHA amount and favored P removal. Also, PHB seems to be the crucial internal carbon source relating to P release and uptake, whereas high nitrogen and P removal efficiencies always relate to a high proportion of PHV in PHA. Increasing carbon loading led to a decreased biodiversity of the community structure but favored higher PAO enrichments, if only P loading is not limited.© 2012 Society of Chemical Industry

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