Ecotoxicological Effects of Micropollutants on Macroinvertebrates

Since the advent of new analytical tools for the chemical assessment of surface waters and the possibility to detect even micrograms of substances in solutions, there is a growing concern about the impact of wastewater discharges on the environment and their incomplete removal by means of conventional wastewater treatment.

Due to concentrations that are exceeding defined levels according to environmental quality standards and are suspected to harm aquatic organisms, there are demands to add a fourth treatment stage for wastewater treatment plants.

In order to investigate the success of an extended wastewater treatment via ozonation, this project explores the effects of conventionally treated and additionally treated wastewater on macroinvertebrates. The usage of relevant macroinvertebrates can address the question, how micropollutants affect the ecological state of surface waters according to the Water Framework Directive. The sewage water to be analyzed also contains diffuse pollutant inputs by rainwater due to mixed water systems. Thus, this research project can supply additional information on pollutant inputs by rainwater management and diffuse inputs of harmful substances.

Six flumes containing different waters (conventionally treated wastewater, ozonated wastewater, control) are used to parallelly expose two macroinvertebrate species in measuring chambers over the course of several weeks. The behavior of the organisms in the different water exposures is monitored via electrodes in the measuring chambers and also recorded and analyzed utilizing a computer program. Furthermore, the stress levels will be measured using biomarker analysis to interlink the individual stress reaction with behavior changes and potential impacts on population dynamics.