Study on ammonia oxidation kinetics of ammonia oxidizer mixed culture

Key words: 
• aerobic ammonium oxidation bacteria /
• ammonium oxidization /
• kinetics

Abstract: The biomass yield coefficient and the maximum specific ammonium nitrogen consumption rate for autotrophic aerobic ammonia oxidation bacteria were 0.2119 mg COD produced/mg NH+4-NOD（or 0.7268 mg COD/mg NH+4-N） and 0.1 mg NOD/（mg COD·h）（or 0.0292 mg N/（mg COD·h）） from batch respirograms. The kinetics of aerobic ammonia oxidation was established by adding 24 μmol/L NaN3 in the sequence batch experiments. The kinetics parameters were determined, where the half saturate coefficient of NH+4-N was 18.38 mg NOD/L （or 5.36 mg NH+4-N/L） and the half saturate coefficient of DO was 0.494 mg/L. The results which were compared with kinetics parameters showed that single-step nitrification models erroneously describe NH+4-N to NO-2-N oxidation.