title: Complete autotrophic denitrification in a single reactor using nitritation and anammox gel carriers.
abstract: A novel aerobic denitrification reactor, aerobic denitrification using nitrifying and anoxic ammonium-oxidizing (anammox) bacteria immobilized on gel carriers in a single stage (AIGES), was developed. Two types of gel carriers, a nitritation gel carrier and an anammox gel carrier, were installed in single reactor, and the denitrification performance of simultaneous nitritation and anammox was evaluated. The denitrification performance increased gradually with increased aeration rate, reaching a denitrification rate of 1.4 kg N m(-3) d(-1) 2 weeks after the nitritation and anammox gel carriers were mixed. A high average denitrification efficiency of 82% was confirmed. Stable aerobic denitrification performance was observed for more than half a year. In the startup period of AIGES operation, ammonia-oxidizing bacteria were shown by fluorescence in situ hybridization analysis to grow on the surface layer of anammox gel cubes. These results indicated that anammox gel carriers promptly adapted to an aerobic environment by altering the microbial ecosystem.
authors.affiliation: Hitachi Ltd., Infrastructure System Company, Matsudo Research Center, Kami-Hongo 537, Matsudo-shi, Chiba 271-0064, Japan. Electronic address: isakakazu@yahoo.co.jp.
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Isaka
authors.affiliation: Hitachi Ltd., Infrastructure System Company, Matsudo Research Center, Kami-Hongo 537, Matsudo-shi, Chiba 271-0064, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Waseda University, Department of Life Science and Medical Bioscience, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Waseda University, Department of Life Science and Medical Bioscience, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Osaka
authors.affiliation: Waseda University, Department of Life Science and Medical Bioscience, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsuneda
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism*; D001483:Base Sequence; D019149:Bioreactors; D017931:DNA Primers; D058440:Denitrification; D017404:In Situ Hybridization, Fluorescence; D009573:Nitrites / Q000378:metabolism*; D016133:Polymerase Chain Reaction
chemical_list: D064751:Ammonium Compounds; D017931:DNA Primers; D009573:Nitrites
keywords: Ammonium; Anammox; Denitrification; Immobilization; Nitrification