Nitrification is an important biochemical process in wastewater treatment by which nitrifying bacteria convert toxic ammonia to less harmful nitrate. Over the last years, the phylogeny of the nitrifying bacteria has been described in more detail. However, there is still little information concerning the factors necessary to maintain a stable operation process and responsible for a disruption or even a break-down of the nitrification performance.

Therefore, the aim of the proposed research project is to conduct a detailed analysis of the composition of the nitrifying bacteria population using fluorescence in-situ hybridization (FISH). This method applies fluorescent gene probes, which bind to specific RNA-sequences of different bacteria, allowing to distinguish different organisms by fluorescence microscopy.

The emphasis of this project lies on waste-water-systems influenced by industrial discharge. Hence, the influence of toxic, refractory or other pollutants as well as of high salt concentrations on the nitrifying bacteria population will be examined. Substances with high pollution priority as well as wastewater relevant parameters are important in this regard. The deepened knowledge obtained by this project will give information about favored environmental conditions of different nitrifying populations resulting in an improved adaptation of the wastewater treatment process and its processing parameters.

Keywords: Wastewater, nitrification, nitrifying bacteria, nitrifying bacteria population, fluorescence in-situ hybridization (FISH), pollutants

EISBANA II