title: [Nitrite accumulation during the denitration process in SBR at low temperature].
abstract: Nitrite accumulation during the denitration process with SBR treating pre-treated by anoxic/anaerobic up-flow anaerobic sludge bed (UASB) was observed at low temperatures. The effects of types of carbon sources on nitrite accumulation were investigated for comprehensive understanding the mechanism of nitrite accumulation. Experimental results clearly showed that nitrite accumulated obviously when five carbon sources (methanol, ethanol, sodium acetate, sodium propinoate and glucose), except for glucose, were used as electron donor. Additionally, nitrite accumulations were observed at four different initial nitrate concentrations and lower temperatures. The maximum concentrations of nitrite accumulation were 37.8, 21.5, 25.2 and 18.8 mg/L, respectively, and the corresponding nitrite accumulation rates (N/VSS x t) were 0.117, 0.136, 0.235 and 0.068 g/(g x d) during the nitrite accumulation period. Two break points of "nitrate knee" and "nitrite knee" on oxidation reduction potential (ORP) profile indicated that the reduction reactions of nitrate and nitrite were completed, respectively.
authors.affiliation: Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China. shw@emails.bjut.edu.cn
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Sun
authors.forename: Shu-ying
authors.initials: SY
authors.lastname: Wang
authors.forename: Xi-ming
authors.initials: XM
authors.lastname: Wang
authors.forename: Xiao-ning
authors.initials: XN
authors.lastname: Shi
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.forename: Yong-zhen
authors.initials: YZ
authors.lastname: Peng
authors.forename: Shu-jun
authors.initials: SJ
authors.lastname: Zhang
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000737:chemistry; D003080:Cold Temperature; D009573:Nitrites / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D009573:Nitrites; D002244:Carbon; D009584:Nitrogen