title: Aerobic granulation for nitrogen removal via nitrite in a sequencing batch reactor and the emission of nitrous oxide.
abstract: In this study, the granulation of nitrifying-denitrifying via nitrite process in a sequencing batch reactor (SBR) as well as N(2)O emission patterns was investigated. After 60 days of operation, 0.8 mm granules were obtained, and partial nitrification was achieved after NH(4)(+)-N was raised to 350 mg/L. Fluorescence In-Situ Hybridization (FISH) analysis indicated that a fairly large proportion of ammonia-oxidizing bacteria (AOB) was close to the surface but nitrite-oxidizing bacteria (NOB) were rarely found. Batch experiments showed that 64.0% of NH(4)(+)-N in influent was transformed into NO(2)(-)-N, which showed the granules had excellent partial nitrification ability. Inhibition of free ammonia (FA) and limited DO diffusion within granules may contribute to the development and stabilization of partial nitrification. This process did not simultaneously lead to increased N(2)O production. N(2)O emissions at the anoxic and aerobic phases were 0.06 and 13.13 mg N(2)O/cycle, respectively.
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, China.
authors.forename: Yi-Jing
authors.initials: YJ
authors.lastname: Shi
authors.forename: Xin-Hua
authors.initials: XH
authors.lastname: Wang
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Yu
authors.forename: Hui-Jun
authors.initials: HJ
authors.lastname: Xie
authors.forename: Shao-Xiang
authors.initials: SX
authors.lastname: Teng
authors.forename: Xue-Fei
authors.initials: XF
authors.lastname: Sun
authors.forename: Bing-Hui
authors.initials: BH
authors.lastname: Tian
authors.forename: Shu-Guang
authors.initials: SG
authors.lastname: Wang
mesh_terms: D001420:Bacteria, Aerobic / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D009573:Nitrites / Q000302:isolation & purification / Q000378:metabolism*; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism*; D009609:Nitrous Oxide / Q000378:metabolism*
chemical_list: D009573:Nitrites; D009609:Nitrous Oxide; D009584:Nitrogen