title: Simultaneous anammox and denitrification (SAD) process in sequencing batch reactors.
abstract: This study investigated nitrogen removal by the simultaneous anaerobic ammonium oxidation (anammox) and heterotrophic denitrification (SAD) process in a sequencing batch reactor (SBR) inoculated with suspended activated sludge and immobilized anammox sludge at various total organic carbon/nitrate (C/N) ratios. Synthetic wastewater containing nitrate 100mg-NL(-1), ammonium 70mg-NL(-1), and acetate 50-250mg-CL(-1) was fed to the SBR. Nitrite reduced from nitrate by heterotrophic denitrification was accumulated and removed with ammonium in each cycle operation of the SBR. The SAD process removed nitrate and ammonium effectively (T-N removal, 58-94%) by the high anammox contribution (ca. 80-100%) under low C/N ratios (0.5-1.0). At high C/N ratios of 1.2-2.5, the SAD process maintained T-N removal 67-79% with predominance of heterotrophic denitrification instead of anammox reaction. Results demonstrated that the SAD process performs high nitrogen removal effectively from wastewater with widely different C/N ratios.
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Takekawa
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Giri
authors.initials: G
authors.lastname: Park
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Soda
authors.affiliation: Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan. Electronic address: ike@see.eng.osaka-u.ac.jp.
authors.forename: Michihiko
authors.initials: M
authors.lastname: Ike
mesh_terms: D064751:Ammonium Compounds / Q000302:isolation & purification / Q000378:metabolism*; D000693:Anaerobiosis; D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D019149:Bioreactors; D002244:Carbon / Q000032:analysis; D058440:Denitrification; D009566:Nitrates / Q000302:isolation & purification; D009584:Nitrogen / Q000032:analysis / Q000302:isolation & purification; D010084:Oxidation-Reduction; D011142:Polyvinyl Alcohol / Q000737:chemistry; D013997:Time Factors
chemical_list: D064751:Ammonium Compounds; D009566:Nitrates; D002244:Carbon; D011142:Polyvinyl Alcohol; D009584:Nitrogen
keywords: Anaerobic ammonium oxidation; C/N ratio; Denitrification