Assessment of the propensity of biofilm growth on newfloat carrier media through process and biological experiments

This paper presents the results of research on biomass growth on Newfloat carrier elements and the implications of this growth on the wastewater treatment process. Supervision of the experiment comprised of the analysis of treatment efficiency (dynamic experiments), the estimation of the content of nitrifying bacteria in the biofilm (batch tests) and biological investigations of the biofilm structure and composition. It has been demonstrated that the biofilm growing on the carrier elements was rich in nitrifying bacteria and that this in turn guaranteed the highly efficient oxidation of ammoniacal nitrogen. After the full growth of biofilm had been established, average removal efficiencies were as follows: organic C removal-88.8% (effluent COD below 60 mg O2 l(-1)), nitrification-97.9% (effluent ammoniacal N below 1 mg N-NH4+ l(-1)), denitrification (after the COD loading rate increased to over 0.53 kg COD m(-3) d(-1))-95.7% (total N in the effluent below 8 mg N l(-1)).