title: High-rate nitrogen removal by the anammox process at ambient temperature.
abstract: The purpose of this study is to investigate the nitrogen removal performance of the anaerobic ammonium oxidation (Anammox) process and the microbial community that enables the Anammox system to function well at ambient temperatures. A reactor with a novel spiral structure was used as the gas-solid separator. The reactor was fed with synthetic inorganic wastewater composed mainly of NH4+-N and NO2--N, and operated for 92 days. Stable nitrogen removal rates (NRR) of 16.3 and 17.5 kg-N m(-3) d(-1) were obtained at operating temperatures of 33±1 and 23±2°C, respectively. To our knowledge, such a high NRR at ambient temperatures has not been reported previously. In addition, the experiments presented herein confirm that high influent NO2--N concentration of 460 mg L(-1) did not noticeably inhibit the Anammox activity. Furthermore, the freshwater Anammox bacterium KU2, which was identified as the dominant bacterial species in the consortium by 16S rRNA gene analysis, is considered to be responsible for the stable nitrogen removal performance at ambient temperatures.
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan. 091d9126@st.kumamoto-u.ac.jp
authors.forename: Jiachun
authors.initials: J
authors.lastname: Yang
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hira
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fukuzaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Furukawa
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D052918:Environmental Restoration and Remediation / Q000379:methods*; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D013696:Temperature; D014835:Volatilization; D014865:Waste Disposal, Fluid
chemical_list: D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D009584:Nitrogen