title: Granulation of Anammox microorganisms in up-flow reactors.
abstract: Experimental studies were performed to evaluate the feasibility of granulation of Anammox microorganisms for biomass retention in up-flow reactors. Two experimental studies, one using a 6.4-L lab-scale reactor with synthetic medium and the other using a 200-L pilot-scale reactor with half-nitrified reject water from a sludge digester were conducted. To enhance the granulation process, seed granules from a UASB reactor were added to both experimental reactors. Granulation of Anammox microorganisms was observed using both the synthetic medium and the reject water. The core of a large proportion of Anammox granules retained part of the original seed biomass. The Anammox granules had a slightly lower density than the seed granules from the UASB process, but the size and other physical properties were comparable. The successful granulation of the Anammox microorganisms led to a stable nitrogen removal performance. The maximum nitrogen removal rate of the lab-scale reactor was observed to be 2.9 kg/(m3 x d) after 173 days of operation and that of the pilot-scale reactor was 6.4 kg/(m3 x d) after 12 months of operation.
authors.affiliation: Kurita Water Industries Ltd., 7-1, Wakamiya, Morinosato, Atsugi-city, Kanagawa, 243-0124, Japan. uraraimj@yahoo.co.jp
authors.forename: U
authors.initials: U
authors.lastname: Imajo
authors.forename: T
authors.initials: T
authors.lastname: Tokutomi
authors.forename: K
authors.initials: K
authors.lastname: Furukawa
mesh_terms: D018533:Biomass; D019149:Bioreactors; D009566:Nitrates; D009573:Nitrites; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism*; D010084:Oxidation-Reduction; D010316:Particle Size; D011157:Population Dynamics; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D009566:Nitrates; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D009584:Nitrogen