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A novel nonwoven hybrid bioreactor (NWHBR) for enhancing simultaneous nitrification and denitrification

Authors

  • Fangang Meng,

    Corresponding author
    1. SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P.R. China; telephone: 86-20-39335060; fax: 86-20-84110267
    2. Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, P.R. China
    • SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P.R. China; telephone: 86-20-39335060; fax: 86-20-84110267.
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  • Yuan Wang,

    1. SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P.R. China; telephone: 86-20-39335060; fax: 86-20-84110267
    2. Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, P.R. China
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  • Li-Nan Huang,

    1. School of Life Sciences, Sun Yat-sen University, Guangzhou, P.R. China
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  • Jie Li,

    1. School of Life Sciences, Sun Yat-sen University, Guangzhou, P.R. China
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  • Feng Jiang,

    1. Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou, P.R. China
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  • Shiyu Li,

    1. SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P.R. China; telephone: 86-20-39335060; fax: 86-20-84110267
    2. Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, P.R. China
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  • Guang-Hao Chen

    1. SYSU-HKUST Research Center for Innovative Environmental Technology (SHRCIET), School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P.R. China; telephone: 86-20-39335060; fax: 86-20-84110267
    2. Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, P.R. China
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Abstract

This study proposed a nonwoven hybrid bioreactor (NWHBR) in which the nonwoven fabric played dual roles as a biofilm carrier and membrane-like separation of the flocculent sludge in the reactor. The results of long-term monitoring demonstrated that the NWHBR could achieve simultaneous nitrification and denitrification (SND), with nearly complete ammonium removal and 80% removal of total nitrogen. The biofilm attached to the nonwoven fabric removed 27% of the chemical oxygen demand (COD) and 36% of the nitrate in the reactor, an enhanced elimination of nutrients that was attributed to the increased mass transfer within the biofilm due to permeate drag. The results of batch experiments showed that the flocculent sludge played a more dominant role in nitrification and denitrification (79% and 61%, respectively) than the biofilm (21% and 36%, respectively). The batch experiments also revealed that the enforced mass transfer, with an effluent recirculation rate of 4.3 L/m2h (which was the same as the flux during the reactor's long-term operation), improved the denitrification rate by 58% (i.e., from 9.0 to 14.2 mg-NOmath image-N/h). Pyrosequencing of the 16S rRNA gene amplification revealed a high microbial diversity in both the flocculent sludge and biofilm, with Proteobacteria, Bacteroidetes and Chloroflexi as the dominant groups. A phylogenetic (P) test indicated that the NWHBR contained phylogenetically distinct microbial communities: those in the biofilm differed from those in the flocculent sludge. However, the communities on the exterior and interior of the biofilm were more similar to each other. Due to its good SND performance, low physical back-washing frequency and low air-to-water ratio, the NWHBR represents an attractive alternative for the wider application of either low-cost membrane bioreactors or biofilm reactors. Biotechnol. Bioeng. 2013; 110: 1903–1912. © 2013 Wiley Periodicals, Inc.

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