Wastewater nitrification kinetics using reciprocating jet bioreactor

Kinetic investigations on growth parameters of nitrifying and COD oxidizing bacteria were carried out with recourse to a three stage reciprocating jet bioreactor system using real life wastewater. The system employed in this investigation essentially consisted of separate aerobic oxidation stage along with nitrification stage and anaerobic denitrification stage with facility for biomass recirculation whenever necessary. Steady-state COD oxidation reactor performance was assessed for various values of residence time. Yield coefficient and decay coefficient of COD oxidizing biomass were obtained as 0.3329 kg BM/kg COD and 0.0032 (1/h) respectively.It was observed that COD oxidizing bacteria co-existed with nitrifying bacteria during nitrification process due to the nature of wastewater used. Steady-state nitrification reactor performance was also assessed for various residence time values. Exact concentration of nitrifying and COD oxidizing biomass in the nitrification reactor was then estimated with the help of kinetic growth parameters of COD oxidizing biomass and extent of COD oxidation achieved in nitrification reactor. This further enabled evaluation of corrected kinetic growth parameters estimated as 0.4272 kg BM/kg NH₄⁺-N and 0.00626 (1/h) for nitrifier biomass yield coefficient and decay coefficient respectively.