Influence of Pollutants on the Bacterial Nitrification in Wastewaters -
Investigations with Fluorescence in-situ Hybridization
(EISBANA II)

In the first part of the research project „EISBANA I“ it was shown that increased salt and DOC concentrations have a strong impact on the nitrification and on the population structure of nitrifying biofilms, while the xenobiotics clofibrinic acid and ibuprofen led only to small effects in wastewater relevant concentrations.

To verify this results miniaturized fixed-bed biofilm reactors will be installed as a bypass system in a wastewater treatment plant to investigate the impact on the nitrifying bacterial population in “real” treatment plants to different characteristics of the wastewater. The investigation includes measurements of the wastewater relevant parameters (e.g. DOC, pH) as well as the nitrogen turnover in combination with a FISH-based population analysis of the nitrifying bacteria. Additionally, the role of ammonium-oxidizing Archaea (AOA) in treatment plants has to be clarified. For this, the occurrence and abundance of the AOA in comparison to the ammonium-oxidizing bacteria have to be determined.

The dominance of nitrite-oxidizing bacteria at different nitrogen concentrations in synthetic wastewaters should be investigated in order to receive a refined picture of the nitrogen conversions during the biological treatment process.