EVALUATION OF BIOLOGICAL TREATMENT OF INDUSTRIAL WASTEWATER USING AEROBIC AND ANAEROBIC RESPIROMETRY

This paper describes studies on an aerobic and anaerobic treatment of an industrial wastewater, contaminated with phenol (560 mg L(-1)) and formaldehyde (480 mg L(-1)), using both aerobic and anaerobic respirometry. Returned activated sludge (RAS) was the source of biomass used in the aerobic studies, digester biomass (DB) was used in anaerobic experiments. Respirometric tests demonstrated that the aerobic system corroborated with the Haldane model for the inhibitory wastes, while data obtained during the anaerobic experiments complied with the Monod model for non-inhibitory wastes. Aerobic treatment of the wastewater/sewage mixture (1:1) removed 46% of formaldehyde and 48% of phenol. For the same wastewater content, the anaerobic removal of formaldehyde and phenol was 73% and 76%, respectively. Results of respirometric tests, biokinetic calculations, and chemical analyses indicated that the anaerobic process was a preferred technology for the investigated wastewater treatment. It has been demonstrated that the anaerobic respirometry can be successfully applied for an investigation of anaerobic processes in a way similar to the aerobic respirometry.