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(M/EH075) Pilot scale application of the autotrophic nitrogen elimination in trickling filters. Neumueller, Birgit1, Twachtmann, Ulf 2, Pinnekamp, Johannes3, Metzger, Joerg4, 1 2 3 4 ABSTRACT- Neumueller B., Twachtmann U., Pinnekamp J., Metzger J., Institut for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Germany. At many municipal wastewater treatment plants a considerable fraction of nitrogen is recirculated from the anaerobic sludge dewatering. This amounts to 20% of the total influent nitrogen load of the wastewater treatment plant. The separate treatment of this sludge liquor creates new capacities for the treatment plant and improves the effluent quality. A new process for treatment of this sludge liquor with ammoniium-nitrogen concentrations above 600 mg/l is the autotrophic denitrification after partial nitritation. At the University of Stuttgart the first semi-technical trickling filter plant was built by which autotrophic denitrification was achieved. At the wastewater treatment plant of Sindelfingen the first pilot-scale implementation of the autorophic denitrification in trickling filters has been designed and built. In a first trickling filter 60 % of the ammonia is transformed to nitrite. To inhibit the nitratation but not the nitritation there must be a specific concentration of free ammonia in this trickling filter. To achieve this, operating conditions as pH and temperature are of great importance. In the second, closed trickling filter (anoxic conditions) ammonium is converted autotrophically to nitrogen with nitrite as electron acceptor. Since November 2000 this plant is operated. First results and experiences for this process in pilot scale application will be presented. Key words: autotrophic denitrification, nitritation, nitratation, trickling filter |
