Nitrifikation im Belebungsverfahren bei maßgebendem Industrieabwassereinfluß

Abstract

Due to the severe impact of ammonia and nitrite on the aquatic environment, constantly low effluent concentrations of these compounds are obligatory for both municipal and industrial wastewater treatment plants. In order to meet this goal, there is hardly a cost-effective alternative to biological nitrification mostly by means of the activated sludge process. Nitrifying bacteria, however, are very sensitive to environmental conditions, especially to inhibitory compounds which can be found in various industrial wastewaters. In several pilot and full-scale plants treating wastewaters influenced by industrial compounds, severe problems with the nitrification process may occur, mainly caused by inhibition. In order to estimate kinetic parameters of nitrifying biomass under these particular conditions, investigations have been carried out using measurements of the respiration rates of the nitrifying biomass as a basis. Methods have been developed for the estimation of the ammonia nitrogen half-saturation coefficient and the 'actual maximum growth rate of the ammonia-oxidising biomass'. These parameters can be evaluated quite frequently during the operation of pilot and full-scale plants and may vary within a wide range. The final aim of all these investigations has been the application of the estimated parameters to simulation models for which examples are presented.