title: Settling velocity of microplastic particles of regular shapes.
abstract: Terminal settling velocity of around 600 microplastic particles, ranging from 0.5 to 5mm, of three regular shapes was measured in a series of sink experiments: Polycaprolactone (material density 1131kgm-3) spheres and short cylinders with equal dimensions, and long cylinders cut from fishing lines (1130-1168kgm-3) of different diameters (0.15-0.71mm). Settling velocities ranging from 5 to 127mms-1were compared with several semi-empirical predictions developed for natural sediments showing reasonable consistency with observations except for the case of long cylinders, for which the new approximation is proposed. The effect of particle's shape on its settling velocity is highlighted, indicating the need of further experiments with real marine microplastics of different shapes and the necessity of the development of reasonable parameterization of microplastics settling for proper modeling of their transport in the water column.
authors.affiliation: Atlantic Branch of P.P. Shirshov Institute of Oceanology of Russian Academy of Sciences, Prospect Mira, 1, Kaliningrad, 236022, Russia; Immanuel Kant Baltic Federal University, A. Nevskogo street, 14, Kaliningrad, 236016, Russia. Electronic address: liliakhatmullina@gmail.com.
authors.forename: Liliya
authors.initials: L
authors.lastname: Khatmullina
authors.affiliation: Atlantic Branch of P.P. Shirshov Institute of Oceanology of Russian Academy of Sciences, Prospect Mira, 1, Kaliningrad, 236022, Russia. Electronic address: isatchenko@gmail.com.
authors.forename: Igor
authors.initials: I
authors.lastname: Isachenko
mesh_terms: D005590:Fractional Precipitation; D019015:Geologic Sediments / Q000737:chemistry*; D008962:Models, Theoretical; D010316:Particle Size; D010969:Plastics / Q000032:analysis* / Q000737:chemistry; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D010969:Plastics; D014874:Water Pollutants, Chemical
keywords: Microplastics; Regular shape; Settling experiment; Theoretical predictions of settling velocity