title: Partial nitrification in an air-lift reactor with long-term feeding of increasing ammonium concentrations.
abstract: The partial nitrification (PN) performance under high ammonium concentrations was evaluated in an airlift reactor (ALR). The ALR was operated for 253days with stepwise elevation of ammonium concentration to 1400mg/L corresponding nitrogen loading rate of 2.1kg/m(3)/d. The ammonium removal rate was finally developed to 2.0kg/m(3)/d with average removal efficiency above 91% and nitrite accumulation percentage of 80%. Results showed that the combined effect of limited DO, high bicarbonate, pH and free ammonia (FA) contributed to the stable nitrite accumulation substantially. The biomass in the ALR was improved with the inception of granulation. Precipitates on biomass surface was unexpectedly experienced which might improve the settleability of PN biomass. Organic functional groups attached to the PN biomass suggested the possible absorbability to different types of pollutant. The results provided important evidence for the possibility of applying an ALR to treat high strength ammonium wastewater.
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors.forename: Li-Yuan
authors.initials: LY
authors.lastname: Chai
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ali
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Min
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors.forename: Yu-Xia
authors.initials: YX
authors.lastname: Song
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China. Electronic address: chjtang@csu.edu.cn.
authors.forename: Chong-Jian
authors.initials: CJ
authors.lastname: Tang
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Changsha 410083, China.
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Yang
mesh_terms: D000388:Air; D064751:Ammonium Compounds / Q000008:administration & dosage / Q000302:isolation & purification / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D004867:Equipment Design; D019544:Equipment Failure Analysis; D058465:Nitrification / Q000187:drug effects / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D064751:Ammonium Compounds; D014874:Water Pollutants, Chemical
keywords: Airlift reactor (ALR); Biological nitrogen removal; High ammonium concentration; Nitritation biomass; Partial nitrification (PN)