---
OA_type: closed access
_id: '19015'
abstract:
- lang: eng
text: When microplastics (MPs) enter water bodies, they undergo various transport
processes, including sedimentation, which can be influenced by factors such as
particle size, density, and interactions with other particles. Surface waters
contain suspended natural particles (e.g., clay and silt), which may impact MP
settling rates. Here, we investigated how the presence of suspended sediments
(SS) influenced the deposition patterns and rates of MPs in turbid waters. We
systematically analyzed the settling velocities of particles, including different
MP sizes and SS concentrations, in a plexiglass column with a camera array. For
each experimental variant, we collected data on thousands of individual MPs, strengthening
the statistical analysis of the particles’ velocities. Simultaneous measurements
of the SS flow and MPs trajectories revealed that the SS induced complex flow
patterns, with MPs spending more time in downwelling flow regions, thereby accelerating
MPs sedimentation. This effect was more pronounced when SS were aggregated. Additionally,
we found that smaller MP fragments were more affected by the fluctuations than
spheres or larger fragments. Collectively, our results provide valuable data for
future MP fate models and help to understand the sedimentation processes of MPs
in natural waters, which is crucial for assessing their environmental transport
and impact.
acknowledgement: F.P. and D.M.M. were funded through the Swiss National Science Foundation
(grant number PCEFP2_186856).
article_processing_charge: No
article_type: original
author:
- first_name: Francesco
full_name: Parrella, Francesco
last_name: Parrella
- first_name: Stefano
full_name: Brizzolara, Stefano
id: 4bbe33b8-c59a-11ee-a1af-fa33d1ac42c4
last_name: Brizzolara
- first_name: Markus
full_name: Holzner, Markus
last_name: Holzner
- first_name: Denise M.
full_name: Mitrano, Denise M.
last_name: Mitrano
citation:
ama: 'Parrella F, Brizzolara S, Holzner M, Mitrano DM. Microplastics settling in
turbid water: Impacts of sediments-induced flow patterns on particle deposition
rates. Environmental Science and Technology. 2025;59(4):2257-2265. doi:10.1021/acs.est.4c10551'
apa: 'Parrella, F., Brizzolara, S., Holzner, M., & Mitrano, D. M. (2025). Microplastics
settling in turbid water: Impacts of sediments-induced flow patterns on particle
deposition rates. Environmental Science and Technology. American Chemical
Society. https://doi.org/10.1021/acs.est.4c10551'
chicago: 'Parrella, Francesco, Stefano Brizzolara, Markus Holzner, and Denise M.
Mitrano. “Microplastics Settling in Turbid Water: Impacts of Sediments-Induced
Flow Patterns on Particle Deposition Rates.” Environmental Science and Technology.
American Chemical Society, 2025. https://doi.org/10.1021/acs.est.4c10551.'
ieee: 'F. Parrella, S. Brizzolara, M. Holzner, and D. M. Mitrano, “Microplastics
settling in turbid water: Impacts of sediments-induced flow patterns on particle
deposition rates,” Environmental Science and Technology, vol. 59, no. 4.
American Chemical Society, pp. 2257–2265, 2025.'
ista: 'Parrella F, Brizzolara S, Holzner M, Mitrano DM. 2025. Microplastics settling
in turbid water: Impacts of sediments-induced flow patterns on particle deposition
rates. Environmental Science and Technology. 59(4), 2257–2265.'
mla: 'Parrella, Francesco, et al. “Microplastics Settling in Turbid Water: Impacts
of Sediments-Induced Flow Patterns on Particle Deposition Rates.” Environmental
Science and Technology, vol. 59, no. 4, American Chemical Society, 2025, pp.
2257–65, doi:10.1021/acs.est.4c10551.'
short: F. Parrella, S. Brizzolara, M. Holzner, D.M. Mitrano, Environmental Science
and Technology 59 (2025) 2257–2265.
date_created: 2025-02-09T23:01:50Z
date_published: 2025-01-27T00:00:00Z
date_updated: 2025-09-30T10:27:26Z
day: '27'
department:
- _id: BjHo
doi: 10.1021/acs.est.4c10551
external_id:
isi:
- '001406914100001'
pmid:
- '39868426'
intvolume: ' 59'
isi: 1
issue: '4'
language:
- iso: eng
month: '01'
oa_version: None
page: 2257-2265
pmid: 1
publication: Environmental Science and Technology
publication_identifier:
eissn:
- 1520-5851
issn:
- 0013-936X
publication_status: published
publisher: American Chemical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Microplastics settling in turbid water: Impacts of sediments-induced flow
patterns on particle deposition rates'
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 59
year: '2025'
...
---
OA_type: closed access
_id: '19035'
abstract:
- lang: eng
text: 'Lagrangian coherent structures (LCSs) are widely recognized as playing a
significant role in turbulence dynamics since they can control the transport of
mass, momentum or heat. However, the methods used to identify these structures
are often based on ambiguous definitions and arbitrary thresholding. While LCSs
theory provides precise and frame-indifferent mathematical definitions of coherent
structures, some of the commonly used extraction algorithms employed in the literature
are still case-specific and involve user-defined parameters. In this study, we
present a new, unsupervised extraction algorithm that enables the extraction of
rotational LCSs based on Lagrangian average vorticity deviation from an arbitrary
3D velocity field. The algorithm utilizes two alternative methods for the identification
of the LCS core (ridge): an unsupervised clustering method and a streamline-based
method. In a subsequent step, the ridge curve is parametrized through a pruning
procedure of minimum spanning tree graphs. To assess the effectiveness of the
algorithm, we test it on two cases: (i) direct numerical simulations of forced
homogeneous and isotropic turbulence and (ii) three-dimensional Particle Tracking
Velocimetry experiments of a turbulent gravity current.'
acknowledgement: M.M.N.H. and M.H. acknowledge financial support from SNSF grant number
200727. M.H. and S.B. acknowledge financial support from the DFG priority program
SPP 1881 Turbulent Superstructures under Grant No. HO5519/1-2.
article_number: '106558'
article_processing_charge: No
article_type: original
author:
- first_name: Marius M.
full_name: Neamtu-Halic, Marius M.
last_name: Neamtu-Halic
- first_name: Stefano
full_name: Brizzolara, Stefano
id: 4bbe33b8-c59a-11ee-a1af-fa33d1ac42c4
last_name: Brizzolara
- first_name: George
full_name: Haller, George
last_name: Haller
- first_name: Markus
full_name: Holzner, Markus
last_name: Holzner
citation:
ama: Neamtu-Halic MM, Brizzolara S, Haller G, Holzner M. Unsupervised extraction
of rotational Lagrangian coherent structures. Computers & Fluids. 2025;290.
doi:10.1016/j.compfluid.2025.106558
apa: Neamtu-Halic, M. M., Brizzolara, S., Haller, G., & Holzner, M. (2025).
Unsupervised extraction of rotational Lagrangian coherent structures. Computers
& Fluids. Elsevier. https://doi.org/10.1016/j.compfluid.2025.106558
chicago: Neamtu-Halic, Marius M., Stefano Brizzolara, George Haller, and Markus
Holzner. “Unsupervised Extraction of Rotational Lagrangian Coherent Structures.”
Computers & Fluids. Elsevier, 2025. https://doi.org/10.1016/j.compfluid.2025.106558.
ieee: M. M. Neamtu-Halic, S. Brizzolara, G. Haller, and M. Holzner, “Unsupervised
extraction of rotational Lagrangian coherent structures,” Computers & Fluids,
vol. 290. Elsevier, 2025.
ista: Neamtu-Halic MM, Brizzolara S, Haller G, Holzner M. 2025. Unsupervised extraction
of rotational Lagrangian coherent structures. Computers & Fluids. 290, 106558.
mla: Neamtu-Halic, Marius M., et al. “Unsupervised Extraction of Rotational Lagrangian
Coherent Structures.” Computers & Fluids, vol. 290, 106558, Elsevier,
2025, doi:10.1016/j.compfluid.2025.106558.
short: M.M. Neamtu-Halic, S. Brizzolara, G. Haller, M. Holzner, Computers &
Fluids 290 (2025).
date_created: 2025-02-17T09:18:41Z
date_published: 2025-03-01T00:00:00Z
date_updated: 2025-09-30T10:34:32Z
day: '01'
department:
- _id: BjHo
doi: 10.1016/j.compfluid.2025.106558
external_id:
isi:
- '001423607400001'
intvolume: ' 290'
isi: 1
language:
- iso: eng
month: '03'
oa_version: None
publication: Computers & Fluids
publication_identifier:
issn:
- 0045-7930
publication_status: published
publisher: Elsevier
quality_controlled: '1'
related_material:
link:
- relation: software
url: https://github.com/NeamtuMarius/Unsupervised-3D-LAVD-Extraction-Algorithm
scopus_import: '1'
status: public
title: Unsupervised extraction of rotational Lagrangian coherent structures
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 290
year: '2025'
...
---
OA_place: publisher
OA_type: hybrid
_id: '19729'
abstract:
- lang: eng
text: 'From anthropogenic litter carried by ocean currents to plant stems travelling
through the atmosphere, geophysical flows are often seeded with elongated, fibre-like
particles. In this study, we used a large-scale laboratory model of a tidal current
– representative of a widespread class of geophysical flows – to investigate the
tumbling motion of long, slender and floating fibres in the complex turbulence
generated by flow interactions with a tidal inlet. Despite the non-stationary,
non-homogeneous and anisotropic nature of this turbulence, we find that long fibres
statistically rotate at the same frequency as eddies of similar size, a phenomenon
called scale selection, which is known to occur in ideal turbulence. Furthermore,
we report that the signal of the instantaneous transverse velocity difference
between the fibre ends changes significantly from the signal produced by the flow
in the fibre surroundings, although the two are statistically equivalent. These
observations have twofold implications. On the one hand, they confirm the reliability
of using the end-to-end velocity signal of rigid fibres to probe the two-point
transverse statistics of the flow, even under realistic conditions: oceanographers
could exploit this observation to measure transverse velocity differences through
elongated floats in the field, where superdiffusion complicates collecting sufficient
data to probe two-point turbulence statistics at a fixed separation effectively.
On the other hand, by addressing the dynamics of inertial range particles floating
in the coastal zone, these observations are crucial to improving our ability to
predict the fate of meso- and macro-litter, a size class that is currently understudied.'
acknowledgement: A.S. expresses thanks for support from the Research Grants Council
of Hong Kong (project IDs 15216422 and C5032-22EF) and from the Research Institute
for Land and Space (RILS) (project ID P0049622). S.B. is funded by the European
Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie
grant agreement (no.101034413).
article_number: A5
article_processing_charge: No
article_type: original
author:
- first_name: Annalisa
full_name: De Leo, Annalisa
last_name: De Leo
- first_name: Stefano
full_name: Brizzolara, Stefano
id: 4bbe33b8-c59a-11ee-a1af-fa33d1ac42c4
last_name: Brizzolara
- first_name: Mattia
full_name: Cavaiola, Mattia
last_name: Cavaiola
- first_name: Junlin
full_name: He, Junlin
last_name: He
- first_name: Alessandro
full_name: Stocchino, Alessandro
last_name: Stocchino
citation:
ama: De Leo A, Brizzolara S, Cavaiola M, He J, Stocchino A. Rigid fibre transport
in a periodic non-homogeneous geophysical turbulent flow. Journal of Fluid
Mechanics. 2025;1011. doi:10.1017/jfm.2025.362
apa: De Leo, A., Brizzolara, S., Cavaiola, M., He, J., & Stocchino, A. (2025).
Rigid fibre transport in a periodic non-homogeneous geophysical turbulent flow.
Journal of Fluid Mechanics. Cambridge University Press. https://doi.org/10.1017/jfm.2025.362
chicago: De Leo, Annalisa, Stefano Brizzolara, Mattia Cavaiola, Junlin He, and Alessandro
Stocchino. “Rigid Fibre Transport in a Periodic Non-Homogeneous Geophysical Turbulent
Flow.” Journal of Fluid Mechanics. Cambridge University Press, 2025. https://doi.org/10.1017/jfm.2025.362.
ieee: A. De Leo, S. Brizzolara, M. Cavaiola, J. He, and A. Stocchino, “Rigid fibre
transport in a periodic non-homogeneous geophysical turbulent flow,” Journal
of Fluid Mechanics, vol. 1011. Cambridge University Press, 2025.
ista: De Leo A, Brizzolara S, Cavaiola M, He J, Stocchino A. 2025. Rigid fibre transport
in a periodic non-homogeneous geophysical turbulent flow. Journal of Fluid Mechanics.
1011, A5.
mla: De Leo, Annalisa, et al. “Rigid Fibre Transport in a Periodic Non-Homogeneous
Geophysical Turbulent Flow.” Journal of Fluid Mechanics, vol. 1011, A5,
Cambridge University Press, 2025, doi:10.1017/jfm.2025.362.
short: A. De Leo, S. Brizzolara, M. Cavaiola, J. He, A. Stocchino, Journal of Fluid
Mechanics 1011 (2025).
date_created: 2025-05-25T22:16:46Z
date_published: 2025-05-16T00:00:00Z
date_updated: 2025-09-30T12:38:34Z
day: '16'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1017/jfm.2025.362
ec_funded: 1
external_id:
isi:
- '001489159700001'
file:
- access_level: open_access
checksum: f1b0f6a977fdf2d6eb9e16c11d030c0c
content_type: application/pdf
creator: dernst
date_created: 2025-05-28T08:12:07Z
date_updated: 2025-05-28T08:12:07Z
file_id: '19751'
file_name: 2025_JourFluidMech_DeLeo.pdf
file_size: 6415303
relation: main_file
success: 1
file_date_updated: 2025-05-28T08:12:07Z
has_accepted_license: '1'
intvolume: ' 1011'
isi: 1
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
project:
- _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c
call_identifier: H2020
grant_number: '101034413'
name: 'IST-BRIDGE: International postdoctoral program'
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Rigid fibre transport in a periodic non-homogeneous geophysical turbulent flow
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 1011
year: '2025'
...