title: Nitrogen removal via nitrite from municipal wastewater at low temperatures using real-time control to optimize nitrifying communities.
abstract: Although many studies regarding nitrogen removal via nitrite have been carried out, very limited research has been undertaken on nitrogen removal via nitrite at low temperatures. In this study, to improve the nitrogen removal efficiency from municipal wastewater, a pilot-plant of sequencing batch reactor with a working volume of 54 m3 was used to investigate nitrogen removal via nitrite from municipal wastewater at normal and low water temperature. The obtained results showed that high nitrogen removal efficiency with effluent total nitrogen below 3 mg/L could be achieved. Using real-time control with temperature ranging from 11.9 to 26.5 degrees C under normal dissolved oxygen condition (> or =2.5 mg/L), nitrogen removal via nitrite was successfully and stably achieved for a long period (180 days) with average nitrite accumulation rate above 95%. Fluorescence in situ hybridization was carried out to investigate the quantitative changes of nitrifying microbial community in the activated sludge. Fluorescence in situ hybridization results approved that the nitrifying microbial communities were optimized; ammonia oxidizing bacteria became the dominant nitrifying bacteria and nitrite oxidizing bacteria had been washed out of the activated sludge.
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100022, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Peng
authors.forename: Xiuhong
authors.initials: X
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Zeng
authors.forename: Takashi
authors.initials: T
authors.lastname: Mino
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Satoh
mesh_terms: D001673:Biodegradation, Environmental; D017753:Ecosystem; D008962:Models, Theoretical; D009573:Nitrites / Q000302:isolation & purification* / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism; D012722:Sewage / Q000032:analysis / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D009573:Nitrites; D012722:Sewage; D009584:Nitrogen