Abstract
Interactions between microplastic (MP) and fine-grained suspended sediment in natural waters are important for the environmental fate of plastic particles. Estuaries are transitional areas between freshwater and open marine systems and are recognized as important accumulation zones for MPs. However, there is a knowledge gap on the processes driving the sedimentation of MPs in estuaries, especially with regard to positively buoyant MPs. Here we show from settling tube experiments that positively buoyant and non-spherical MP HDPE particles in different size-fractions (63–500 μm) and concentrations (1 and 5 mg l−1) rapidly flocculate and settle with natural fine-grained sediment in natural seawater. Our results demonstrate that flocculation is a key process for the vertical transport of MP in estuaries. The implication is that land-based sources of positively buoyant HDPE MP transported by rivers will likely settle and accumulate in estuarine environments and thereby increase the concentration of MP in the benthic zone.
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | 113619 |
| Tidsskrift | Marine Pollution Bulletin |
| Vol/bind | 178 |
| Antal sider | 10 |
| ISSN | 0025-326X |
| DOI | |
| Status | Udgivet - 2022 |
Bibliografisk note
Funding Information:This work was supported by the Villum-Experiment grant no. 17668 by the Villum Foundation and grants to the projects PlasticHotspot (project no. 3-2018 ) and TRACE (project no. 2-2020 ) by Geocenter Denmark . We would like to thank Stiffani Rominikan for fruitful cooperation in and outside the laboratory.
Publisher Copyright:
© 2022 The Authors