Sampling concept for microplastics in combined sewage-affected freshwater and freshwater sediments

Abstract

The pollution of the environment with microplastics is an issue of great concern, with research of this topic focusing on the sampling and analysis of microplastics. As the sampling method is connected to the matrices from which the samples are collected, there is no general method for the analysis of microplastics, neither in water nor in sediments and, especially, there is no existing method for combined sewage. To obtain comparable results of samples from different matrices, we present a concept based on samples taken from combined sewage, combined sewage-affected freshwater, and freshwater sediments, which were prepared analogously in a treatment process to establish an equivalent starting sample for further analysis. The concept is based on a filter disc (stainless-steel, 47-mm diameter, 20-mu m mesh size) for sampling the different water and sediments. With this filter disc, the removal of organic and anorganic matrices was conducted and then used to generate subsamples of different size fractions, which are identical for all samples and complete the sampling concept.