1ST PRACTICAL EXPERIENCES WITH SUBMERGED ROPE-TYPE BIO-FILM REACTORS FOR UPGRADING AND NITRIFICATION

The upgrading and nitrification was required for the waste water treatment plant in Geiselbullach. As space for more aeration tanks was not available, the possibility of increasing the MLSS by the use of submerged bio-film reactors was tested in a half technical scale pilot plant with three different reactor materials. Each tested reactor material caused a significant increase of MLSS and the nitrification reaction. The rope-type material was selected for the practical application, as it had not the same disadvantages of the other tested systems, which proved operational problems. After one year of continuous operation for nitrification in the full scale plant the influences on the biomass characteristics were investigated. Design criteria and details and operational data are reported.