TY - JOUR

T1 - Settling velocity of microplastic particles having regular and irregular shapes

AU - Goral, Koray Deniz

AU - Guler, Hasan Gokhan

AU - Eltard Larsen, Bjarke

AU - Carstensen, Stefan

AU - Christensen, Erik Damgaard

AU - Kerpen, Nils B

AU - Schlurmann, Torsten

AU - Fuhrman, David R

N1 - Funding Information: This research has been financially supported by the Independent Research Fund Denmark project MPCOAST: MicroPlastic transport processes in the COASTal environment, grant no. 0136-00227B . The second author additionally acknowledges financial support from The Scientific and Technical Research Council of Turkey (TUBITAK) under the 2219 International Postdoctoral Research Fellowship Programme . This support is greatly appreciated.

PY - 2023/7/1

Y1 - 2023/7/1

N2 - The settling velocities of 66 microplastic particle groups, having both regular (58) and irregular (eight) shapes, are measured experimentally. Regular shapes considered include: spheres, cylinders, disks, square plates, cubes, other cuboids (square and rectangular prisms), tetrahedrons, and fibers. The experiments generally consider Reynolds numbers greater than 10 2, extending the predominant range covered by previous studies. The present data is combined with an extensive data set from the literature, and the settling velocities are systematically analyzed on a shape-by-shape basis. Novel parameterizations and predictive drag coefficient formulations are developed for both regular and irregular particle shapes, properly accounting for preferential settling orientation. These are shown to be more accurate than the best existing predictive formulation from the literature. The developed method for predicting the settling velocity of irregularly-shaped microplastic particles is demonstrated to be equally well suited for natural sediments in the Appendix.

AB - The settling velocities of 66 microplastic particle groups, having both regular (58) and irregular (eight) shapes, are measured experimentally. Regular shapes considered include: spheres, cylinders, disks, square plates, cubes, other cuboids (square and rectangular prisms), tetrahedrons, and fibers. The experiments generally consider Reynolds numbers greater than 10 2, extending the predominant range covered by previous studies. The present data is combined with an extensive data set from the literature, and the settling velocities are systematically analyzed on a shape-by-shape basis. Novel parameterizations and predictive drag coefficient formulations are developed for both regular and irregular particle shapes, properly accounting for preferential settling orientation. These are shown to be more accurate than the best existing predictive formulation from the literature. The developed method for predicting the settling velocity of irregularly-shaped microplastic particles is demonstrated to be equally well suited for natural sediments in the Appendix.

KW - Microplastic particles

KW - Non-buoyant

KW - Settling velocity

UR - http://www.scopus.com/inward/record.url?scp=85152093401&partnerID=8YFLogxK

U2 - 10.1016/j.envres.2023.115783

DO - 10.1016/j.envres.2023.115783

M3 - Article

C2 - 37028533

VL - 228

JO - Environmental research

JF - Environmental research

SN - 0013-9351

M1 - 115783

ER -