title: Nitrogen removal using an anammox membrane bioreactor at low temperature.
abstract: Membrane bioreactors (MBRs) have the ability to completely retain biomass and are thus suitable for slowly growing anammox bacteria. In the present study, an anammox MBR was operated to investigate whether the anammox activity would remain stable at low temperature, without anammox biomass washout. The maximum nitrogen removal rates were 6.7 and 1.1 g-N L⁻¹ day⁻¹ at 35 °C and 15 °C, respectively. Fluorescence in situ hybridization and 16S rRNA-based phylogenetic analysis revealed no change in the predominant anammox species with temperature because of the complete retention of anammox biomass in the MBR. These results indicate that the predominant anammox bacteria in the MBR cannot adapt to a low temperature during short-term operation. Conversely, anammox activity recovered rapidly after restoring the temperature from the lower value to the optimal temperature (35 °C). The rapid recovery of anammox activity is a distinct advantage of using an MBR anammox reactor.
authors.affiliation: EcoTopia Science Institute, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Awata
authors.affiliation: Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan E-mail: tomokin@hiroshima-u.ac.jp.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan E-mail: tomokin@hiroshima-u.ac.jp.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kindaichi
authors.affiliation: Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan E-mail: tomokin@hiroshima-u.ac.jp.
authors.forename: Noriatsu
authors.initials: N
authors.lastname: Ozaki
authors.affiliation: Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan E-mail: tomokin@hiroshima-u.ac.jp.
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Ohashi
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D003080:Cold Temperature; D058440:Denitrification / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D017404:In Situ Hybridization, Fluorescence; D008567:Membranes, Artificial; D009584:Nitrogen / Q000378:metabolism*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D062065:Wastewater / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D009584:Nitrogen; D012336:RNA, Ribosomal, 16S; D062065:Wastewater