Characteristics of biofilm attaching to carriers in moving bed biofilm reactor used to treat vitamin C wastewater

Authors

  • Xiao-bing Hu,

    1. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, People's Republic of China
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  • Ke Xu,

    1. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, People's Republic of China
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  • Zhao Wang,

    1. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, People's Republic of China
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  • Li-li Ding,

    1. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, People's Republic of China
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  • Hong-qiang Ren

    Corresponding author
    1. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu, People's Republic of China
    • Address for reprints: Hong-Qiang Ren, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, Jiangsu, People's Republic of China E-mail: hqren@mail.nju.edu.cn, hxb1612@yahoo.cn

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  • This article was published online on 20 November 2012. Subsequently, it was determined that the funding information was incorrect, and the corrected article was published online on 7 December 2012.

  • Contract grant sponsor: National High-tech R&D Program of China (863 Program); Contract grant number: 2012AA063407.

Summary

In order to investigate characteristics of biofilm attaching firmly to carriers in the moving bed biofilm reactor (MBBR) used for vitamin C wastewater treatment, experiments were undertaken with instrumental analysis methods. Scanning electron microscopy (SEM) micrographs of MBBR biofilms revealed that there were rod-shaped microbes and cocci in the biofilm, and microbes were embedded within medium substances and the biofilm matrix adhered firmly to carriers, leading to the formation of a smooth compacted surface at the base of the biofilm. Transmission electron microscopy (TEM) analysis revealed that extracellular polymeric substances (EPS) layer surrounded cell, sequestered inorganics to form a mixed structure, which ensured firm attachment of the biofilm to the carrier. X-ray diffraction (XRD) experiments and thermogravimetry analysis revealed that (i) the biofilm contained many inorganic substances, about 70.5%, and the inorganic substances contained multiple classes of inorganic with a high boiling point; (ii) inorganic elements such as calcium and phosphorous were selectively absorbed and accumulated in the biofilm as insoluble compounds with amorphous phases, rendering the biofilm highly resistant to detachment. Fourier-transform infrared (FTIR) spectroscopy showed carbohydrates were the main EPS. SCANNING 35:283-291, 2013. © 2012 Wiley Periodicals, Inc.

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