Plastics, Water and the Environment
Comparability of Microplastics and Natural Sediment
We believe that sedimentology can provide valuable insights to guide future microplastics research. To advance our understanding of the comparability of natural sediments with microplastics, we took an interdisciplinary look at the existing literature describing particle properties, transport processes, sampling techniques and ecotoxicology. Based on our analysis, we define seven research goals that are essential to improve our understanding of microplastics and can be tackled by learning from natural sediment research, and identify relevant tasks to achieve each goal. Sounds interesting? Click here to read more!
Settling and Rising Behaviour of Micro- and Macroplastics in a stable water column
The settling and rising behaviour of plastic particles highly influences the transport behaviour in rivers and is thus a very important variable for hydro numerical simulations. We have looked at the settling and rising behaviour of virgin and weathered microplastics and compared the results to the basics from natural sediment transport. Additionally, we studied the settling and rising velocities of common macroplastic foils, as their vertical transport behaviour differs significantly from other micro- and macroplastic particles.
Erosion Behaviour of Microplastics from different sediments
Rivers are often only seen as transport paths for microplastics from inland sources to the oceans, although transport rates in rivers can hardly be determined yet. In this study, the critical shear stresses of 14 microplastic particles with different shapes, densities and particle sizes on different sediment beds were experimentally determined and subsequently compared with the basic principles of erosion from sediment transport.
Infiltration Behaviour of Microplastics into different Sediments
In this study, the infiltration behaviour of 21 microplastic particles with different densities, diameters, and shapes was investigated using columns of glass spheres with different grain diameters. Our study provides initial indications of reasonable sampling depths in dependence of the grain sizes of the bottom sediment and the microplastic particles.
Vertical Distribution of Microplastics in the Water Column
The current approaches to monitoring fluvial transport of microplastic pollution primarily sample the surface of water bodies, but how reliable are those environmental concentrations? We adapted the Rouse profile to show that fluvial transport of microplastic pollution includes all traditional domains of transport, as well as additional domains specific to low-density materials with rising velocities in water.
Research Trip to India
In November 2019, I had the pleasure to travel to India for work. My colleague and I stayed for three weeks in Chennai (Tamil Nadu) and for one week in Munnar (Kerala). There, we took water samples in three rivers to compare urban and rural microplastic concentrations in the Indian fluvial environment. The results have recently been published and can be accessed here.