My interests include the broadly understood biological wastewater treatment process with the activated sludge method. In my professional work I deal with, among others, biological analysis of activated sludge and the importance of microfauna in the biological treatment of wastewater using the activated sludge method. In addition, in the area of my interests there are problems related to the removal of nutrients from wastewater (N, P), with particular emphasis on the nitrification process (adaptation of nitrifiers to unfavorable conditions, including inhibitory substances), determining the causes of excessive development of filamentous organisms in the activated sludge and assessment the effectiveness of biological wastewater treatment in reducing sanitation indicators. In the research conducted so far, I also dealt with the analysis of the microbiological quality of the atmospheric air in the sewage treatment plant and in other municipal facilities.