title: Novel autotrophic nitrogen removal system using gel entrapment technology.
abstract: A pilot plant involving a nitritation-anammox process was operated for treating digester supernatant. In the preceding nitritation process, ammonium-oxidizing bacteria were immobilized in gel carriers, and the growth of nitrite-oxidizing bacteria was suppressed by heat-shock treatment. For the following anammox process, in order to maintain the anammox biomass in the reactor, a novel process using anammox bacteria entrapped in gel carriers was also developed. The nitritation performance was stable, and the average nitrogen loading and nitritation rates were 3.0 and 1.7 kg Nm(-3)d(-1), respectively. In the nitritation process, nitrate production was completely suppressed. For the anammox process, the startup time was about two months. Stable nitrogen removal was achieved, and an average nitrogen conversion rate of 5.0 kg Nm(-3)d(-1) was obtained. Since the anammox bacteria were entrapped in gel carriers, stable nitrogen removal performance was attained even at an influent suspended solids concentration of 1500 mg L(-1).
authors.affiliation: Hitachi Plant Technologies Ltd., Kami-Hongo 537, Matsudo, Chiba 271-0064, Japan. kazuichi.isaka.mp@hitachi-pt.com
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Isaka
authors.forename: Hiroki
authors.initials: H
authors.lastname: Itokawa
authors.forename: Yuya
authors.initials: Y
authors.lastname: Kimura
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Noto
authors.forename: Takao
authors.initials: T
authors.lastname: Murakami
mesh_terms: D001419:Bacteria / Q000378:metabolism; D018533:Biomass; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism; D010865:Pilot Projects
chemical_list: D009584:Nitrogen