Buoyant microplastics in freshwater sediments - How do they get there?
Molazadeh, Marziye (Aalborg Universitet. Department of the Built Environment)
Simon-Sánchez, Laura (Universitat Autònoma de Barcelona. Institut de Ciència i Tecnologia Ambientals)
Liu, Fan (Aalborg Universitet. Department of the Built Environment)
Vollersten, Jes (Aalborg Universitet. Department of the Built Environment)

Date:	2023
Description:	10 pàg.
Abstract:	The accumulation of microplastics (MPs) in the sediments of a stormwater treatment pond was studied to gain knowledge on how these facilities protect the natural environment against this emerging pollutant. Thirteen sediment samples were analyzed for MPs down to 10 μm, mapping the pattern of accumulation in the pond. The average abundance in terms of MP-number and mass was 11. 8 μg kg−1 and 44,383 item kg−1, respectively. They were rather unevenly distributed, with concentrations varying up to two orders of magnitude within the pond, showing that a trustworthy quantification of MPs retained by such units must rely on many and well-distributed subsamples. Buoyant MPs made up 95. 4 % of the MP-mass and 83. 5 % of the MP-number and in most of the sampled locations, polypropylene dominated the polymer fingerprint, followed by polyethylene. No spatial pattern in the distribution of MPs in the pond was identified. Instead, the MP content correlated to the organic matter and silt content, indicating that the processes leading to deposition could be similar. A computational fluid dynamics model was set up and used to simulate the transport mechanisms governing the conveyance of MPs in the pond from water to sediments. The results showed that the combination of advection and dispersion were likely the driving mechanism for buoyant (and non-buoyant) MPs to get in contact with the sediment bed and spread over the pond. Once in contact with the sediments, the MPs would have some probability of being permanently incorporated and hereby preventing them from entering the downstream aquatic environment.
Grants:	European Commission 860720
Note:	Unidad de excelencia María de Maeztu CEX2019-000940-M
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Buoyant MPs ; Stormwater ponds ; Sediments ; CFD
Published in:	Science of the total environment, Vol. 860 (February 2023) , art. 160489, ISSN 1879-1026

DOI: 10.1016/j.scitotenv.2022.160489
PMID: 36455730

10 p, 2.4 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Institut de Ciència i Tecnologia Ambientals (ICTA)
Articles > Research articles
Articles > Published articles