Papers

61,005 results
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Article Tier 2

Entrainment and vertical mixing of aquatic microplastics in turbulent flow: The coupled role of particle size and density

Researchers conducted laboratory flume experiments to study how turbulence affects the vertical mixing and entrainment of microplastic particles of different sizes and densities. Both particle size and polymer density significantly influenced mixing behavior, with smaller and denser particles more responsive to turbulent structures, informing models of microplastic transport in rivers and coastal waters.

2022 Marine Pollution Bulletin 50 citations
Article Tier 2

Vertical transport of buoyant microplastic particles in the ocean: The role of turbulence and biofouling

Researchers modeled how turbulence and biofouling interact to determine the vertical movement of buoyant microplastic particles in the ocean. They identified three distinct flow regimes that govern whether microplastics stay at the surface, oscillate, or sink to the seafloor. The study helps explain the observation that even low-density microplastics are found in deep ocean sediments, suggesting biofouling-driven density changes are a key transport mechanism.

2025 Environmental Pollution 9 citations
Article Tier 2

Microplastics segregation by rise velocity at the ocean surface

This study modeled the competing forces of particle buoyancy and turbulent mixing that control the vertical distribution of microplastics in the ocean surface layer, finding that particle rise velocity is the key variable that segregates plastic types and determines how they distribute relative to surface and subsurface measurements.

2023 Environmental Research Letters 23 citations
Article Tier 2

The role of turbulence in the deposition of intrinsically buoyant MPs

This flume study found that turbulence causes the vertical velocity of buoyant polyethylene microplastics to vary over 4 orders of magnitude compared to their rise rate in still water, explaining how lighter-than-water particles end up deposited in river and lake sediments.

2023 The Science of The Total Environment 19 citations
Article Tier 2

The effect of wind mixing on the vertical distribution of buoyant plastic debris

Researchers modeled and measured how wind mixing affects the vertical distribution of buoyant plastic debris in the ocean, finding that turbulent mixing drives plastics below the surface and explains why surface sampling underestimates total plastic concentrations.

2012 Geophysical Research Letters 701 citations
Article Tier 2

Quantifying the influence of size, shape, and density of microplastics on their transport modes: A modeling approach

Researchers developed a computer model that predicts how microplastics of different sizes, shapes, and densities move through ocean water. The model accurately simulates whether particles float on the surface, stay suspended in the water column, or settle to the bottom. Understanding how microplastics travel through marine environments is important for predicting where contamination accumulates and which seafood sources are most likely to be affected.

2024 Marine Pollution Bulletin 19 citations
Article Tier 2

Sinking microplastics in the water column: simulations in the Mediterranean Sea

Researchers simulated the vertical dispersion and distribution of negatively buoyant microplastics in the Mediterranean Sea using a realistic circulation model, evaluating how inertia, Coriolis force, turbulence, and variable seawater density affect sinking trajectories and accumulation zones.

2021 Ocean science 49 citations
Article Tier 2

Physical transport properties of marine microplastic pollution

Researchers reviewed the physical transport properties of marine microplastics — including buoyancy, settling velocity, and biofouling effects — and developed models predicting the dispersal of both pelagic and benthic plastic pollution from land-based sources across different ocean regions. The study highlights how hydrodynamic behavior varies by polymer type and particle size, leading to differential accumulation patterns in surface waters, the water column, and seafloor sediments.

2012 182 citations
Article Tier 2

The effect of particle properties on the depth profile of buoyant plastics in the ocean

Using sampling at multiple depths from 0 to 5 meters in the North Atlantic subtropical gyre, researchers measured how turbulent mixing redistributes buoyant microplastics below the ocean surface. The results show that surface net sampling alone significantly underestimates total microplastic concentrations, particularly in windy conditions.

2016 Scientific Reports 277 citations
Article Tier 2

Microplastics Transport in Turbulent Flow: Investigating the Effects of Physical Characteristics and Flow Dynamics

This PhD dissertation investigated how the physical properties of microplastics — density, size, and shape — affect their transport and mixing in turbulent aquatic flows using numerical simulations and experiments. Lower-density, smaller, and non-spherical particles deviate most from fluid streamlines, explaining why these types are found far from their sources.

2024 York University Digital Library (York University)
Article Tier 2

Factors influencing the vertical distribution and transport of plastics in riverine environments: Theoretical background and implications for improved field study design.

This review examines the physical and hydrodynamic factors governing the vertical distribution and transport of plastics in riverine environments, synthesizing theoretical background on settling velocity, turbulence, and buoyancy to provide recommendations for improved field study design.

2025 Environmental pollution (Barking, Essex : 1987)
Article Tier 2

On the vertical structure of non-buoyant plastics in turbulent transport

Researchers investigated how non-floating plastic debris moves through river-like flows and found that plastics settle in unique, complex patterns due to their irregular shapes. In low-turbulence conditions, interactions between the plastic particles and the riverbed enhanced mixing beyond what standard sediment transport models would predict. The study proposes a new equation for describing how plastics are distributed vertically in flowing water.

2024 Water Research 22 citations
Article Tier 2

Occurrence And Fate Of Microplastics In Urban Freshwater Systems

Microplastics were found in urban freshwater pond sediments at highly variable concentrations, with buoyant particles dominating by mass and water mixing playing a key role in distributing plastic particles through the water column.

2023
Article Tier 2

Influence of Settling/Rising Velocity on the Vertical Distribution of Microplastics in the Marine Environment

Researchers used a three-dimensional Lagrangian dispersion model incorporating mean ocean currents and subgrid-scale turbulence to simulate the vertical distribution of microplastics in marine environments, assigning particles a spectrum of settling and rising velocities reflecting the diversity of microplastic sizes, shapes, and densities. Results showed that using a probability distribution of velocities rather than a single value substantially alters predicted vertical concentration profiles throughout the water column.

2024 1 citations
Article Tier 2

Elucidating the vertical transport of microplastics in the water column: A review of sampling methodologies and distributions

This review synthesized sampling methodologies and findings on microplastic vertical distribution in the water column, identifying that surface trawl studies dramatically underestimate total water column burdens and that sinking behavior, biofouling, and hydrodynamic processes create complex depth-dependent distribution patterns.

2020 Water Research 93 citations
Article Tier 2

Microplastic Pathways: Investigating Vertical and Horizontal Movement from Riverine Environments to Oceans

Researchers investigated the vertical and horizontal movement of microplastics in riverine systems en route to the ocean, examining how physical MP characteristics and hydrodynamic conditions govern whether particles settle near riverbeds or float at the surface, and how both gravity-driven and flow-driven transport contribute to their ultimate fate.

2025
Article Tier 2

Study of the influence of fluvial dynamics on the distribution and transport of microplastics.

Researchers studied how fluvial dynamics including flow velocity, turbulence, and river geomorphology influence the distribution and transport of microplastics in river systems. River hydrodynamics were found to be major determinants of where microplastics accumulate and how far they travel, with implications for predicting contamination patterns in river catchments.

2024 Zenodo (CERN European Organization for Nuclear Research)
Article Tier 2

Horizontal Dispersion of Buoyant Materials in the Ocean Surface Boundary Layer

This theoretical and computational study examined how buoyant materials like plastic fragments are dispersed horizontally in the ocean surface layer by turbulent mixing processes. The modeling results help explain how surface microplastics spread and whether they reach zones of biological concentration.

2018 Journal of Physical Oceanography 33 citations
Article Tier 2

Distribution of Plastics of Various Sizes and Densities in the Global Ocean From a 3D Eulerian Model

Using a three-dimensional Eulerian transport model, researchers simulated global ocean distribution of microplastics across different sizes and densities, finding that particle buoyancy and size strongly govern vertical distribution and that significant MP fractions sink to deeper ocean layers.

2025 Journal of Geophysical Research Oceans 2 citations
Article Tier 2

Catching the variety: Obtaining the distribution of terminal velocities of microplastics particles in a stagnant fluid by a stochastic simulation

A stochastic simulation model was used to estimate the distribution of settling and rising speeds for microplastic particles of varying size, shape, and density in still water. Understanding how microplastics move through water columns is essential for predicting where they accumulate and how organisms are exposed.

2020 Marine Pollution Bulletin 21 citations
Article Tier 2

Aggregation of Slightly Buoyant Microplastics in Three-Dimensional Vortex Flows

This modeling study found that slightly buoyant microplastics preferentially accumulate in vorticity-dominated regions below the ocean surface in three-dimensional eddy flows. This explains why microplastics are found throughout the water column rather than just at the surface, and has implications for their ingestion by organisms at various depths.

2023 1 citations
Article Tier 2

Modeling the settling and resuspension of microplastics in rivers: Effect of particle properties and flow conditions

Researchers developed a mathematical model to simulate how microplastics of different shapes settle and resuspend in rivers, moving beyond the common assumption that all particles are spherical. They found that turbulence has a complex effect, sometimes keeping particles suspended longer and sometimes accelerating their settling, depending on flow conditions. The model reveals that particle shape significantly influences where microplastics end up in river systems.

2024 Water Research 36 citations
Article Tier 2

The vertical distribution of buoyant plastics at sea: an observational study in the North Atlantic Gyre

Field measurements of buoyant plastic particles at multiple depths in the ocean showed that concentrations decrease sharply below a few meters, with turbulence mixing plastics downward. The data validate model predictions and confirm that surface net trawls substantially undercount total plastic in the water column.

2015 Biogeosciences 498 citations
Article Tier 2

Plastic drift : Mapping the course of microplastic transport in turbulent riverine flows.

Researchers conducted laboratory experiments tracking the 3D trajectories of 24 negatively buoyant microplastic particles spanning a range of sizes, shapes, and densities in turbulent open channel flow, generating 720 trajectories to evaluate how well conventional sediment transport models apply to microplastics. Results revealed that the inherent variability in microplastic physical properties challenges direct application of sediment transport concepts to microplastic fate prediction in rivers.

2024 Zenodo (CERN European Organization for Nuclear Research)