title: Simultaneous nitrification and denitrification of municipal wastewater in aerobic membrane bioreactors.
abstract: Simultaneous nitrification-denitrification (SND) of municipal wastewater was investigated in a laboratory-scale membrane bioreactor (MBR) operated at two different hydraulic retention times (HRTs), 0.5 and 1 day, dissolved oxygen 3.0 to 0.5 mg/L, and solids retention time (SRT) between 28 and 120 days. The organic loading rate (OLR) (0.11 to 0.64 kg chemical oxygen demand [COD]/m3/d) and influent soluble COD (SCOD)/ total Kjeldahl nitrogen (TKN) ratio (5 to 19) were varied by the addition of glucose. The ammonia-nitrogen and TKN removals were over 97%, and total nitrogen removal was approximately 89% in the MBR. The maximum specific nitrification rates (98 mg N/d/g VSS) and specific denitrification rates (81 mg N/d/g VSS) occurred at an SCOD/TKN ratio of 9.1. The optimum conditions for maximum total nitrogen removal by SND in a single reactor MBR have been found to be low dissolved oxygen (< 0.6 mg/L) and high OLR (approximately 0.64 kg COD/m3/d) at an HRT of 0.5 day and SRT of approximately 85 days.
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, Chicago, Illinois 60616, USA.
authors.forename: Seung H
authors.initials: SH
authors.lastname: Baek
authors.forename: Krishna R
authors.initials: KR
authors.lastname: Pagilla
mesh_terms: D000332:Aerobiosis; D000641:Ammonia / Q000737:chemistry / Q000302:isolation & purification; D019149:Bioreactors; D004305:Dose-Response Relationship, Drug; D008567:Membranes, Artificial; D009566:Nitrates / Q000737:chemistry* / Q000302:isolation & purification; D009584:Nitrogen / Q000737:chemistry* / Q000302:isolation & purification; D010100:Oxygen / Q000494:pharmacology; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D009566:Nitrates; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen