title: Simultaneous denitrification and phosphorus removal by Agrobacterium sp. LAD9 under varying oxygen concentration.
abstract: Although efficient aerobic denitrification has received increasing attention, few studies have been made on simultaneous denitrification and phosphorus removal (SDPR) under aerobic condition. In this study, SDPR by an efficient aerobic denitrifier, Agrobacterium sp. LAD9, was firstly demonstrated. High nitrate and phosphorus removal rates of 7.50 and 1.02 mg L(-1) h(-1) were achieved in wide range of O2 concentration from 5.92 to 20.02 mg L(-1). The N2O production would be inhibited as O2 concentration exceeded 11.06 mg L(-1), while the phosphorus removal efficiency would be generally improved with increasing O2 concentration. (15)N mass spectrometry revealed that nitrogen removal accorded with the typical aerobic denitrification pathway, while (31)P nuclear magnetic resonance spectroscopy ((31)P NMR) indicated the fate of phosphorus to cells, extracellular polymeric substances (EPS), and polyphosphate (poly-P) of the denitrifier. EPS acted as a reservoir of phosphorus and the transformation of poly-P was dynamic and depended on initial orthophosphate (ortho-P) content. The aerobic SDPR would greatly simplify the conventional wastewater treatment processes which required separated considerations of nitrogen and phosphorus removal.
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences (Ministry of Education), Peking University, Beijing, 100871, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Ma
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences (Ministry of Education), Peking University, Beijing, 100871, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences (Ministry of Education), Peking University, Beijing, 100871, People's Republic of China.
authors.forename: Mengyao
authors.initials: M
authors.lastname: Gui
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences (Ministry of Education), Peking University, Beijing, 100871, People's Republic of China.
authors.forename: Can
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Environmental Engineering, Key Laboratory of Water and Sediment Sciences (Ministry of Education), Peking University, Beijing, 100871, People's Republic of China. jinrenni@pku.edu.cn.
authors.forename: Jinren
authors.initials: J
authors.lastname: Ni
mesh_terms: D000332:Aerobiosis / Q000502:physiology; D060054:Agrobacterium / Q000187:drug effects / Q000378:metabolism*; D058440:Denitrification / Q000502:physiology; D006801:Humans; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology; D010758:Phosphorus / Q000302:isolation & purification / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000382:microbiology*
chemical_list: D009566:Nitrates; D009584:Nitrogen; D010100:Oxygen; D010758:Phosphorus; D062065:Wastewater
keywords: Aerobic denitrifier; Extracellular polymeric substances; Intracellular poly-P; SDPR