Microplastics are plastic parts that are smaller than 5 mm in diameter. These are detected ubiquitously in the environment in the form of particles, fibres, microbeads or pellets and are associated with potential hazards to ecosystems. To date, however, neither the exact concentrations of microplastics in the various ecosystems nor their exact sources and routes of entry are known.
Due to plastic abrasion and the widespread use of plastic products in households, clothing, cosmetics, domestic wastewater is a potential source of micro-plastics discharge into the aquatic environment. However, considerable research is still needed on the discharge of microplastics from wastewater treatment plants, such as sewage treatment plants and combined water treatment plants.
As part of the MiKaMiresearch project – “Input of Microplastics from Wastewater Treatment Plants – Sewage Treatment Plants and Mixed Water Treatment Plants,” the input potential of microplastics from waste water treatment plants shall be investigated. To this end, three wastewater treatment plants with different sizes and cleaning technologies as well as a mixed water treatment plant are being investigated.
Based on the investigations, further knowledge shall be gained about microplastic concentration in the inflow of sewage treatment plants and about the retention capacity of microplastics in the individual purification stages of conventional wastewater treatment.
In addition, the input potential of microplastics into waters of sewage treatment plant effluents is compared with the potential of mixed water discharges. To this end, sampling techniques and investigation methods from other research programs will also be taken into account and, where appropriate, harmonized for the German federal state of North Rhine-Westphalia.