title: Effect of influent nitrogen speciation on organic nitrogen occurrence in activated sludge process effluents.
abstract: The effect of influent nitrogen composition on organic nitrogen production in a sequencing batch reactor (SBR) activated sludge process was investigated. A laboratory-scale SBR was fed with three different type synthetic wastewaters with varying nitrogen compositions (phase I = nitriloacetic acid + ammonium [NH4-N], phase II = NH(4-)N, and phase III = amino acid mixture + NH(4-)N) was operated. The effluent contained approximately 1 to 2 mg N/L organic nitrogen, even though there was no organic nitrogen in influent. The effluent organic nitrogen increased to approximately 4 mg N/L when the influent composition was changed and then stabilized at <2 mg N/L. The maximum nitrifier growth rate constants (microN) were calculated as 0.91+/-0.10 to 1.14+/-0.08 day-1, 0.82 +/-0.13 day-1, and 0.89+/-0.08 day-1 at 20 degrees C for the three different influent compositions. The effluent colloidal organic nitrogen (CON) was negligible, suggesting that the effluent CON found in full-scale plants may be the result of influent-derived suspended matter.
authors: Civil, Architectural, and Environmental Engineering Department, Illinois Institute of Technology, Chicago, Illinois 60616, USA. pagilla@iit.edu
authors: K
authors: K
authors: Pagilla
authors: C
authors: C
authors: Sattayatewa
authors: M
authors: M
authors: Urgun-Demirtas
authors: S
authors: S
authors: Baek
mesh_terms: D019149:Bioreactors; D009584:Nitrogen / Q000737:chemistry* / Q000378:metabolism; D017672:Nitrogen Compounds / Q000737:chemistry* / Q000378:metabolism; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism
chemical_list: D017672:Nitrogen Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical; D009584:Nitrogen