Microplastic- and Nanoplastic Particles as Carrier of Urban Stormwater Pollutants and their Removal Mechanisms in Alternative Sorption Materials

The aim of this research project is to determine the processes involved in the transport of metals and organic pollutants on the surfaces of micro- and nanoplastic particles (MNPs) and to investigate the sorption processes of MNPs on sustainable sorption materials for the treatment of polluted stormwater. Selected MNPs are those commonly found in urban stormwater, such as tyre wear particles, PE and PA, and they have different chemical surface properties, physical sizes and shapes, and are thus expected to have different sorption strengths and mechanisms for different types of pollutants. Mixtures of the selected MNPs are tested in batch-beaker experiments to determine the sorption capacity, kinetics, and isotherms of selected stormwater pollutants, including Cu, Zn, Pb, Cr, Cd, Ni, and PAH-16. Data are then fitted to kinetic and isothermal models to determine the type of sorption processes involved for each pollutant. Thereafter, MNP´s sorption capacity is evaluated on sustainable materials, such as biochar, bark, and ash, in both batch and column experiments. Finally, the morphology, particle shape, elemental composition and organic chemical composition of sorbent materials before and after the tests are visualized and analyzed using SEM-EDX and ToF-SIMS. The research deepens the understanding of how pollutants and MNPs are transported in the environment but also provides basic knowledge to be able to develop innovative filters for the treatment of polluted water.