title: Oxygen-limited nitrification and denitrification in a lab-scale rotating biological contactor.
abstract: Rotating Biological Contactors (RBC) treating highly nitrogenous wastewaters are known to give rise to nitrogen losses, generally assumed to be due to concomitant nitrification and denitrification. In this study, a lab-scale nitrifying RBC reactor was shown to bring about losses of nitrogen of the order of 10 to 20% at ammonium loading rates of up to 2129 mg N m(-2) d(-1), when no extra carbon source was added. These higher removal values could be due to Oxygen-Limited Autotrophic Nitrification and Denitrification (OLAND), because the reactor was operated at oxygen limitation. When methanol was added as a soluble organic carbon source to further diminish oxygen transfer into the deeper parts of the biofilm, the RBC achieved 84% nitrogen removal (loading rate 2300 mg N m(-2) d(-1)) at a COD/N ratio of 3.1. The latter also suggests that the process was occurring parallel to conventional denitrification.
authors: Laboratory of Microbial Ecology and Technology, Ghent University, Gent, Belgium.
authors: K
authors: K
authors: Pynaert
authors: R
authors: R
authors: Sprengers
authors: J
authors: J
authors: Laenen
authors: W
authors: W
authors: Verstraete
mesh_terms: D019149:Bioreactors; D009584:Nitrogen / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D000644:Quaternary Ammonium Compounds; D009584:Nitrogen; D010100:Oxygen