Water Environment Research · 1994 · 34 citations · 0 references
EngineeringBiological EngineeringEnvironmental EngineeringBioreactor DesignWastewater TreatmentWater TreatmentActivated Sludge ProcessBiological Treatment ProcessesNitrogen RemovalNutrient RemovalSludge ManagementSludge TreatmentAerationBiological Nitrogen RemovalBiological Wastewater TreatmentDenitrificationDenitrification ProcessesMicroscopic MorphologyPartial DenitrificationWastewater Treatment Nutrient Removal
ABSTRACT: The installation of continuous on‐line measurements of ammonium and nitrate in the aeration tanks of a nitrogen removing activated sludge plant has reduced the nitrate amount in the effluent by 60%. This corresponds to a drop in the average total nitrogen concentration in the effluent from 7.8 mg/L to 5.1 mg/L. The operation of the nitrogen removal process and thereby the effluent concentrations has become more stable. By combining operational changes in the biosorption with on‐line control of the process, it is possible to maintain full and stable denitrification at a BOD/N ratio of 3 to 4 without the use of any external carbon source, despite great variations in the loading of the plant. Monitoring of the microscopic characteristics of the sludge can be closely correlated with macroscopic characteristics such as sludge volume index.