Koray Deniz Goral, Hasan Gokhan Guler, Bjarke Eltard Larsen, Stefan Carstensen, Erik Damgaard Christensen, Nils B. Kerpen, Torsten Schlurmann and David R. Fuhrman (2023). Shields Diagram and the Incipient Motion of Microplastic Particles. Environmental Science & Technology. https://doi.org/10.1021/acs.est.3c02027
The volume of plastic waste in nature (oceans, coastal regions, reefs, glaciers, etc.) is increasing rapidly and has reached highly concerning levels. Once in aquatic environments, the understanding of their fundamental transport processes is presently in its infancy. Although the incipient motion of sediments has been studied extensively in the literature, only a small number of experiements studied the fundamental incipient motion conditions for microplastic particles.
As part of the collaboration of the MPCoast Project coleagues at DTU measured the incipient motions of 65 microplastic particle groups having regular (57) and irregular (eight) shapes and proposed a new predictive framework for variations in static friction, hydraulic roughness, and hiding-exposure effects. A new framework for predicting incipient motion conditions for foreign microplastic particles has been developed. The method accounts for differences in static friction, hydraulic roughness (through the grain Reynolds number), as well as hiding-exposure effects. This framework has, for the first time, been shown to reconcile incipient motion conditions for foreign microplastic particles with the classical Shields diagram, as commonly utilized, e.g., for predicting the incipient motion of natural sediments.
Links:
