Experimental study of non-buoyant microplastic transport beneath breaking irregular waves on a live sediment bed

Experimental investigation on the nearshore transport of buoyant microplastic particles

“…dimensional number is known to be extremely important within the field of coastal sediment transport and is commonly used to predict coastal profile types (Wright and Short, 1984). Recently, Guler et al (2022) demonstrated that accumulation hotspots of non-buoyant microplastic particles were likewise largely governed by the Dean number, thereby underlining the importance of this parameter for coastal transport of microplastic particles as well. For the Lagrangian transport velocity of buoyant microplastic particles this parameter is believed to be especially important in the surf zone, where wave breaking can cause the buoyant particles to be submerged for a significant period of time in dependence of their individual rise velocities, as discussed in Section 3.2.…”

“…For the non-buoyant particles, the accumulation was seen to depend on a dimensionless fall velocity. Finally, Guler et al (2022) studied the transport patterns of non-buoyant particles in a small-scale wave flume under irregular breaking and nonbreaking waves. They identified four different accumulation hotspots along the coastal profile and the non-dimensional Dean number as an important factor in determining these.…”

“…With the exception of Guler et al (2022), the previous studies have all utilized monochromatic waves, and the Lagrangian velocities of the particles have only been investigated in non-breaking waves (Alsina et al, 2020). The present study aims to further improve the quantitative understanding of wave-induced cross-shore transport of buoyant microplastic particles beneath both non-breaking and breaking irregular waves.…”

Shields Diagram and the Incipient Motion of Microplastic Particles

“…Note that 18 of the particle groups (2−6, 16, 20, 24−27, 29, 30, 32−34, 38, and 45) were also used in separate wave flume experiments of Guler et al (2022). 17 Additionally, with the exception of particle group 1, all of the present particles were considered in the separate settling velocity experiments of Goral et al (2023). 18 Microplastic spheres were purchased from a local supplier.…”

“…The microplastic particle densities ρ p have been determined through titration, inspired by the ISO (2012) 19 standard, as also done by Khatmullina and Isachenko (2017), 20 Guler et al (2022), 17 and Goral et al (2023). 18 Distilled water was poured into a plastic container, and selected particles from each group were individually placed inside this container.…”