Modeling and experimental study on the anaerobic/aerobic/anoxic process for simultaneous nitrogen and phosphorus removal: The effect of acetate addition

Koichi Soejima, Shinya Matsumoto, Satoshi Ohgushi, Kensuke Naraki, Akihiko Terada, Satoshi Tsuneda, Akira Hirata

Research output: Contribution to journalArticle

17 Citations (Scopus)


A mathematical model based on the simulation software AQUASIM was developed to validate an anaerobic/aerobic/anoxic (AOA) process that enables simultaneous nitrogen and phosphorus removal in a single reactor by adding external organic carbon to preclude excess aerobic phosphate uptake by polyphosphate-accumulating organisms (PAOs) and provide phosphate for denitrifying PAOs (DNPAOs). Aerobic batch tests after anaerobic phosphate release with different chemical oxygen demand (COD) concentrations indicated that the effect of COD concentration on the phosphate uptake preclusion could be expressed by a simple formula. The reduction factor reflecting the formula, which retards the aerobic phosphate uptake in the presence of COD, was added to the process rates of aerobic polyphosphate storage and PAOs growth in the model. The improved model, which included the reduction factor, reasonably matched the experimental result regarding aerobic phosphate uptake behavior whereas the model without it did not; thus, the former precisely predicts the AOA process behavior.

Original languageEnglish
Pages (from-to)605-614
Number of pages10
JournalProcess Biochemistry
Issue number6
Publication statusPublished - 2008 Jun 1



  • Anaerobic/aerobic/anoxic process (AOA process)
  • Denitrifying polyphosphate-accumulating organisms (DNPAOs)
  • Enhanced biological phosphorus removal (EBPR)
  • Process modeling
  • Sequencing batch reactor (SBR)

ASJC Scopus subject areas

  • Bioengineering
  • Biochemistry
  • Applied Microbiology and Biotechnology

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