Impact of Selected Pollutants in Synthetic Industrial Wastewater on Nitrifying Biofilms in Fixed Bed Biofilm Reactors‐Visualized with Fluorescence In‐Situ Hybridization

Abstract

The impact of selected pollutants on the structure and activity of nitrifying bacterial populations within fixed bed biofilm reactors was examined. Clofibrinic acid and ibuprofen as pharmaceutically active compounds were added to a synthetic wastewater fed to the biofilm reactors and the concentrations of chloride and dissolved organic carbon were also varied. Clear impacts of increased salt and dissolved organic carbon concentrations on nitrification activity and nitrifying bacterial populations were observed whereas clofibrinic acid (up to 100 µg/l) and ibuprofen (10 µg/l) showed no impact on the nitrification activity. The exposure to clofibrinic acid also showed no significant influence on the nitrifying bacterial population, while the addition of ibuprofen resulted in a slight shift of the population to a lower abundance of the β‐proteobacteria.

Keywords:

• Nitrification
• pollutant
• wastewater treatment
• ibuprofen
• clofibrinic acid
• salinity (chloride)
• DOC
• fluorescence in‐situ hybridization

The work was financially supported by the Deutsche Forschungsgemeinschaft (DFG). We thank Matthias Weber, Elly Karle and Rafael Peschke for their fine analytical work.