Das Projekt "Industrielle Loesung fuer das Nitratproblem im Abwasser" wird vom Umweltbundesamt gefördert und von Dynamit Nobel Wien, Werk St. Lambrecht durchgeführt. Waste water resulting from the production of explosives is cleaned of contaminants by an ecological, energy-saving method with comparatively low operating costs until conditions for main outfall discharge have been achieved. The water contains a large number of contaminants, some in extremely high concentrations. The primary objective of the project is to remove high concentrations of nitrate and organic nitro compounds usually found in the waste water of this industry with the aim of enabling direct discharge of treated waste water into main outfall. The set objective was already attained in the laboratory within the scope of the three-year research project. The results achieved led to the building of a pilot plant and to the planning of a microbiologically functioning large-scale plant. In 1994, the company Dynamit Nobel produced the first positive results in microbial treatment of the plant's waste water. The treatment plant (pilot plant) comprises three stages for the constituents of the accumulated plant waste water. In the first aerobic phase organic substances are mineralized; in the second aerobic phase nitrites and nitrates are removed by denitrification. In the third aerobic phase, the residual carbon is degraded. After adding growth factors, the process waste water is fed into the plant, re-diluting it as far as possible with the aim of achieving constant concentrations of contamination. The aerobic pre-treatment and post-treatment are performed with the aid of specially adapted and mixed microbial cultures partially immobilised on special growth base material, in a specially developed combination of activated sludge and fluidized bed reactors. During operation of the pilot plant and during preliminary laboratory trials, it was shown that the degradation capacity of the mix is very high. However, it is also greatly dependent upon disturbances in operation conditions when up-scaled to industrial size.