Experimental investigation on the nearshore transport of buoyant microplastic particles

authored by

Bjarke Eltard Larsen, Mustafa Ali Abdullah Al-Obaidi, Hasan Gokhan Guler, Stefan Carstensen, Koray Deniz Goral, Erik Damgaard Christensen, Nils B. Kerpen, Torsten Schlurmann, David R. Fuhrman

Abstract

This paper presents experimental measurements of beaching times for buoyant microplastic particles released, both in the pre-breaking region and within the surf zone. The beaching times are used to quantify cross-shore Lagrangian transport velocities of the microplastics. Prior to breaking the particles travel onshore with a velocity close to the Lagrangian fluid particle velocity, regardless of particle characteristics. In the surf zone the Lagrangian velocities of the microplastics increase and become closer to the wave celerity. Furthermore, it is demonstrated that particles having low Dean numbers (dimensionless fall velocity) are transported at higher mean velocities, as they have a larger tendency to be at the free-surface relative to particles with higher Dean numbers. An empirical relation is formulated for predicting the cross-shore Lagrangian transport velocities of buoyant microplastic particles, valid for both non-breaking and breaking irregular waves. The expression matches the present experiments well, in addition to two prior studies.

Organisation(s)

Ludwig-Franzius-Institute of Hydraulics, Estuarine and Coastal Engineering

External Organisation(s)

Technical University of Denmark
Middle East Technical University (METU)

Type

Article

Journal

Marine pollution bulletin

Volume

187

ISSN

0025-326X

Publication date

02.2023

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Pollution, Aquatic Science, Oceanography

Research Area (based on ÖFOS 2012)

Hydraulic engineering

Sustainable Development Goals

SDG 14 - Life Below Water, SDG 6 - Clean Water and Sanitation

Electronic version(s)

https://doi.org/10.1016/j.marpolbul.2023.114610 (Access: Open)