Effects of SRT and DO on N2O reductase activity in an anoxic-oxic activated sludge system

Naohiro Noda, N. Kaneko, M. Mikami, Y. Kimochi, Satoshi Tsuneda, A. Hirata, M. Mizuochi, Y. Inamori

    Research output: Contribution to journalArticle

    62 Citations (Scopus)

    Abstract

    Nitrous oxide (N2O) is emitted from wastewater treatment processes, and is known to be a green house gas contributing to global warming. It is thus important to develop technology that can suppress N2O emission. The effects of sludge retention time (SRT) and dissolved oxygen (DO) on N2O emission in an anoxic-oxic activated sludge system were estimated. Moreover, the microbial community structure in the sludge, which plays an important role in N2O suppression, was clarified based on nitrous oxide reductase (nosZ) gene analysis by molecular biological techniques. The results showed that under low SRT conditions, nitrification efficiency was reduced and the N2O emission rate in the oxic reactors was increased. It was also observed that N2O emission was enhanced under low DO conditions, where the available oxygen is insufficient for nitrification. Moreover, molecular analysis revealed that the clones identified in this study were closely related to Ralstonia eutropha and Paracoccus denitrificans. The fact that the identified sequences are not closely related to known culturable denitrifier nosZ sequences indicates a substantial in situ diversity of denitrifiers contributing to N2O suppression, which are not reflected in the cultivatable fraction of the population. The further application of these new molecular techniques should serve to enhance our knowledge of the microbial community of denitrifying bacteria contributing to N2O suppression in wastewater treatment systems.

    Original languageEnglish
    Pages (from-to)363-370
    Number of pages8
    JournalWater Science and Technology
    Volume48
    Issue number11-12
    Publication statusPublished - 2004

    Fingerprint

    Nitrification
    Dissolved oxygen
    Wastewater treatment
    activated sludge
    dissolved oxygen
    sludge
    Oxides
    Global warming
    nitrous oxide
    Greenhouse gases
    nitrification
    microbial community
    Bacteria
    Genes
    Oxygen
    molecular analysis
    clone
    global warming
    community structure
    greenhouse gas

    Keywords

    • Denitrification
    • Dissolved oxygen
    • Global warming
    • Nitrification
    • nosZ
    • sludge retention time

    ASJC Scopus subject areas

    • Water Science and Technology

    Cite this

    Noda, N., Kaneko, N., Mikami, M., Kimochi, Y., Tsuneda, S., Hirata, A., ... Inamori, Y. (2004). Effects of SRT and DO on N2O reductase activity in an anoxic-oxic activated sludge system. Water Science and Technology, 48(11-12), 363-370.

    Effects of SRT and DO on N2O reductase activity in an anoxic-oxic activated sludge system. / Noda, Naohiro; Kaneko, N.; Mikami, M.; Kimochi, Y.; Tsuneda, Satoshi; Hirata, A.; Mizuochi, M.; Inamori, Y.

    In: Water Science and Technology, Vol. 48, No. 11-12, 2004, p. 363-370.

    Research output: Contribution to journalArticle

    Noda, N, Kaneko, N, Mikami, M, Kimochi, Y, Tsuneda, S, Hirata, A, Mizuochi, M & Inamori, Y 2004, 'Effects of SRT and DO on N2O reductase activity in an anoxic-oxic activated sludge system', Water Science and Technology, vol. 48, no. 11-12, pp. 363-370.
    Noda, Naohiro ; Kaneko, N. ; Mikami, M. ; Kimochi, Y. ; Tsuneda, Satoshi ; Hirata, A. ; Mizuochi, M. ; Inamori, Y. / Effects of SRT and DO on N2O reductase activity in an anoxic-oxic activated sludge system. In: Water Science and Technology. 2004 ; Vol. 48, No. 11-12. pp. 363-370.
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