title: One-stage partial nitritation and anammox in membrane bioreactor.
abstract: Partial nitritation and anammox (PN/A) was applied in a lab-scale membrane bioreactor (MBR) to investigate its technical feasibility for treating ammonium-rich wastewater with low C/N ratio. The bacterial community was analyzed by molecular cloning and 16S rRNA sequence analysis. Partial nitritation (PN) was first realized in MBR by seeding aerobic activated sludge. With dissolved oxygen control, a steady effluent mixture with NO2 (-)-N/NH4 (+)-N ratio of 1.13 ± 0.08 was generated from the PN process. Subsequently, the MBR was seeded with anammox biomass on day 59. After running 300 days, the one-stage PN/A achieved a maximum nitrogen removal rate of 1.45 kg N/m(3)/day at the nitrogen removal efficiency of 89.5 %. Microbial community analysis revealed that Nitrosomonas sp. HKU and Nitrosospira sp. YKU corresponded to nitritation; meanwhile, Candidatus Brocadia TKU sp. accounted for nitrogen removal of the PN/A system. Specifically, Nitrosomonas sp. were enriched in the reactor at the PN/A phase and then conquered Nitrosospira sp. to be the predominant ammonia oxidizers. Nitrite oxidizers and denitrifiers were detected in symbiosis with aforementioned microbes. Denitrification promised potential plus nitrogen depletion. The present one-stage PN/A process allows a significant decrease in operational costs compared with classical nitrification/denitrification.
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan. xwhuang2010@gmail.com.
authors.forename: Xiaowu
authors.initials: X
authors.lastname: Huang
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan.
authors.forename: Kaihang
authors.initials: K
authors.lastname: Sun
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan.
authors.forename: Qiaoyan
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Urata
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yamashita
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan.
authors.forename: Nian
authors.initials: N
authors.lastname: Hong
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan.
authors.forename: Takehide
authors.initials: T
authors.lastname: Hama
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto, 860-8555, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kawagoshi
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D058465:Nitrification; D009584:Nitrogen / Q000378:metabolism*; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000032:analysis* / Q000382:microbiology*
chemical_list: D009584:Nitrogen; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D062065:Wastewater
keywords: Anammox; Membrane bioreactor; Nitrogen removal; Partial nitritation