Surface runoff

It is not easy to determine how much microplastic is contained in wastewater and sewage sludge. In addition to plastic, countless other particles and substances are present. To reliably determine the concentration of microplastic particles, complex procedures for sampling as well as for removal of foreign substances and analysis of the microplastic particles are required.

Plastic is now ubiquitous not only in the sea but also in many inland waters. In certain areas, such as at barrages or in dams, the flow velocity decreases. As a result, the particles previously held in suspension by the current begin to sink to the bottom of the water and can then accumulate in the sediment.

Microplastics can enter our wastewater along the entire value chain. Removal options exist primarily in wastewater treatment plants, here in the form of filtration, flotation and sedimentation processes. The removal performance of wastewater treatment plants determines how much microplastic is discharged into the environment.