The number of synthetic organic chemical compounds today adds up to more than 60 million. Their release into the environment and into the water cycle shows an increasing trend by multiple pathways. Due to advanced analytical methods the residues of these chemicals, so called micropollutants [Definitions], can be detected easier today and thus their ecological impacts can be evaluated better than during last decades.
Although the quality of water bodies in North Rhine-Westphalia (NRW) has improved during the last decade, it is still far from reaching to a good ecological status as required by the EU water framework directive. One reason for that is the occurrence of micropollutants in water bodies.
Due to the increasing use of multiple chemicals for industrial and domestic use (e.g. pharmaceuticals, cosmetics and personal care products, household and processing chemicals), more and more micropollutants enter municipal sewage systems. These are then discharged into surface waters. Conventional wastewater treatment plants (WWTP) are usually equipped with mechanical-biological treatment, which is not designed to eliminate micropollutants from waste water. Although some compounds can be removed in these conventional WWTP, others will not be degraded or only to a small extent. Therefore, municipal WWTP represent a very important entry pathway of micropollutants into surface waters. Additionally, industrial plants, which discharge their wastewater directly into surface waters after treating, as well as diffuse sources, e.g. from agricultural applications, are also accountable for the occurrence of micropollutants in water bodies.
A further challenge for the natural water bodies is the pollution by microplastics. Microplastics are small plastic particles, which enter the WWTP and surface waters, for instance, by household uses of cosmetics (e.g. body scrubs or toothpaste with plastic pearls). The formation and spreading of microplastics also depends on larger plastic waste, which might enter surface waters or WWTP due to improper waste dumping or storm events. Their size is then reduced through mechanical or environmental factors. As no detailed knowledge about the transport and occurrence of microplastics in the environment is available, there is an urgent need for research to develop suitable analytical methods and approaches to reduce the release of microplastics into the environment. The competence centre for micropollutants NRW (KOM-M.NRW) addresses this group of topics in order to sensitize and inform the general public about environmental occurrences and impacts of microplastics in the environment.