Dr. Domańska to study sewage

– I have been working with the identification of microorganisms by fluorescence hybridisation in situ (FISH) for years, but in this project I will be investigating the composition of microorganisms not only in biological reactors, but also in the effluent using modern molecular biology techniques – says Dr. Magdalena Domańska, adding that despite the dynamic development of molecular methods they are still not a standard approach in wastewater treatment plants.

– Activated sludge technology is currently the most commonly used method of biological treatment of municipal and industrial wastewater. Activated sludge is a complex structure of microorganisms, with a dynamically changing composition depending on the operating conditions of the wastewater treatment plant. Understanding the structure of activated sludge microorganisms, as well as the changes in their quantitative and qualitative composition over time, provides valuable insight into the functioning of biological reactors. Learning about specific groups of microorganisms is essential for resolving issues related to insufficient removal of nitrogen or phosphorus compounds, or those related to sludge swelling. We can often observe an excessive discharge of bacteria from the settling tanks into the drain, which happens if adverse conditions arise in the reactor, e.g. an influx of industrial wastewater. With this research project I would like to find out whether the presence or absence of specific groups of bacteria in the effluent can indicate the quality of the sewage treatment process – explains Dr. Magdalena Domańska, adding that she will be carrying out the research project in cooperation with the Institute of Biochemistry and Biophysics of the Polish Academy of Sciences in Warsaw.

The outcome of the project will be the selection of nitrifying bacteria carried into the recycling pits with the treated sewage, and the identification of which groups of microorganisms involved in the transformation of nitrogen compounds prevail in activated sludge, and which ones in the effluent, and also whether this is a seasonal phenomenon.

– Successful projects are always the result of the work of many people, and I would like to thank the staff of the Institute of Environmental Engineering who have supported me in these efforts, as well as Prof. Janusz Łomotowski for his invaluable suggestions – emphasises Dr. Domańska.