Papers

61,005 results
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Article Tier 2

A Study on Shape-Dependent Settling of Single Particles with Equal Volume Using Surface Resolved Simulations

This fluid dynamics study developed new mathematical models to predict how particle shape influences the settling speed of particles in liquid. While focused on engineering applications, this type of research is relevant to understanding how differently shaped microplastic particles distribute and accumulate in water bodies.

2021 Computation 20 citations
Article Tier 2

Effect of Shape and Size on the Transport of Floating Particles on the Free Surface in a Meandering Stream

Using particle tracking in a field-scale meandering stream, researchers found that the shape and size of floating particles — including microplastics — significantly affect how they move with water currents. Irregularly shaped particles behave differently than spheres, which matters for predicting where plastic pollution accumulates in waterways.

2023 2 citations
Article Tier 2

Settling velocity of irregularly shaped microplastics under steady and dynamic flow conditions

The settling velocities of irregularly shaped microplastics were measured under both still water and dynamic flow conditions, finding that shape strongly affected settling speed and that turbulence caused non-spherical particles to orient and settle differently than spheres, with implications for predicting microplastic vertical transport in rivers and coastal waters.

2021 Environmental Science and Pollution Research 92 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

Coupled CFD-DEM modelling to assess settlement velocity and drag coefficient of microplastics

Researchers used computational fluid dynamics coupled with particle simulations to model how the size, shape, and density of microplastics affect their settling velocity and drag in water. Accurate physical models of microplastic behavior are essential for predicting where particles accumulate in rivers, lakes, and the ocean.

2020 1 citations
Article Tier 2

On some physical and dynamical properties of microplastic particles in marine environment

This study examined the physical and dynamical properties of microplastic particles in marine environments, using modeling to predict how particle shape, density, and size govern transport, dispersion, and accumulation patterns.

2016 Marine Pollution Bulletin 629 citations
Article Tier 2

Settling of inertial nonspherical particles in wavy flow

Lab experiments showed that plastic particles of different shapes — rods, disks, and spheres — settle at different rates in wavy water, and waves can both speed up and slow down their sinking. Understanding how particle shape affects transport in ocean currents is key to predicting where microplastics accumulate.

2020 Physical Review Fluids 21 citations
Article Tier 2

A settling velocity formula for irregular shaped microplastic fragments based on new shape factor: Influence of secondary motions

Researchers developed a new shape factor for irregular microplastic fragments and derived a settling velocity formula based on it, using numerical modeling to show that fragment shape governs whether particles sink stably or oscillate — providing more accurate predictions of microplastic transport in rivers and lakes than existing methods.

2024 The Science of The Total Environment 7 citations
Article Tier 2

Effect of Shape and Size on the Transport of Floating Particles on the Free Surface in a Natural Stream

Researchers used particle tracking velocimetry to study how shape and size affect the movement of floating particles on the turbulent free surface of a natural stream, finding that millimeter-scale spheres behaved differently from centimeter-scale irregular objects. Understanding particle transport mechanics is essential for predicting microplastic fate in river systems.

2023 Water Resources Research 17 citations
Article Tier 2

Mobility and retention of microplastic fibers and irregular plastic fragments in fluvial systems: an experimental flume study

Researchers conducted experimental flume studies to compare the mobility and retention of microplastic fibres and irregularly shaped plastic fragments in fluvial systems. The study found that particle shape strongly influences transport behaviour, with fibres exhibiting greater mobility and distinct retention patterns compared to irregular fragments, highlighting the need to move beyond spherical particle models in microplastic transport research.

2025 Microplastics and Nanoplastics
Article Tier 2

Settling velocity of microplastic particles having regular and irregular shapes

Researchers measured how quickly microplastic particles of various shapes settle through water, testing 66 different particle types including spheres, cylinders, fibers, and irregular fragments. They found that particle shape significantly affects settling speed, with fibers and flat shapes sinking more slowly than spheres of the same size. The study provides new equations for predicting where microplastics end up in oceans and waterways based on their shape.

2023 Environmental Research 86 citations
Article Tier 2

Towards better predicting the settling velocity of film-shaped microplastics based on experiment and simulation data

Researchers combined experimental and simulation data to better predict how film-shaped microplastics settle through water, since most existing models are based on spherical particles. They found that the particle definition approach was more suitable than equivalent spherical diameter for characterizing flat, irregular microplastics. The improved settling velocity predictions could help scientists better understand how film-shaped microplastics travel and accumulate in aquatic environments.

2024 Marine Pollution Bulletin 10 citations
Article Tier 2

Empirical Shape-Based Estimation of Settling Microplastic Particles Drag Coefficient

This study experimentally measured the settling behavior of flat square microplastic particles in water, finding that shape significantly affects sinking speed and drag compared to spherical particles. Understanding how microplastic shapes influence settling is essential for modeling where plastics accumulate in rivers and ocean sediments.

2023 Journal of Marine Science and Engineering 2 citations
Article Tier 2

Microplastic and natural sediment in bed load saltation: Material does not dictate the fate

Researchers investigated how microplastics move as bed load in river flows and found that transport behavior in saltation was governed primarily by particle size, shape, and density rather than material composition, suggesting that microplastics follow similar transport mechanics as natural sediment.

2023 Water Research 44 citations
Article Tier 2

Improving predictions of microplastic incipient motion through shields parameter modifications

Researchers developed modifications to the Shields parameter to better predict the incipient motion of microplastics in aquatic sediment environments, addressing how the irregular shapes and densities of MP particles deviate from assumptions built for conventional sediment transport models.

2025
Article Tier 2

Response of microplastic particles to turbulent flow: An experimental study

Using controlled flume experiments, researchers studied how turbulent flow conditions affect the transport and settling behavior of microplastic particles with varied shapes and densities, finding that turbulence intensity and particle morphology interacted to determine suspension and deposition patterns.

2025
Article Tier 2

Settling of nonuniform cylinders at intermediate Reynolds numbers

This study investigated the settling behavior of non-uniform cylindrical particles at intermediate Reynolds numbers, providing new data on how particle shape and aspect ratio influence drag and settling velocity. The findings are relevant to predicting the transport and deposition of microplastic fibers in water.

2024 Physical Review Fluids 7 citations
Article Tier 2

Transport of anisotropic particles under waves

A computer model showed that non-spherical particles (like many microplastic fragments and fibers) behave differently from spherical ones in wave-driven water flow, affecting how they orient and where they travel. Accounting for particle shape is important for accurately predicting where microplastic debris accumulates in coastal and ocean environments.

2017 Journal of Fluid Mechanics 77 citations
Article Tier 2

Dispersion of finite-size, non-spherical particles by waves and currents

Researchers conducted laboratory experiments to measure the dispersion of non-spherical, negatively buoyant particles — including discs, rods, and cylinders — in combined wave-current flows, providing empirical data relevant to understanding how microplastic particles of varying shapes travel through aquatic environments. Their results show that particle shape significantly influences dispersion patterns, with implications for predicting microplastic transport and distribution in coastal and riverine systems.

2022 Journal of Fluid Mechanics 14 citations
Article Tier 2

Effect of shape on the transport and retention of nanoplastics in saturated quartz sand

Researchers compared the transport of spherical versus toroid-shaped nanoplastics through quartz sand columns, finding that irregular toroid particles traveled significantly less far than spheres due to lower energy barriers and greater tendency to accumulate along pore walls — highlighting that particle shape must be considered when predicting nanoplastic fate in soil and groundwater.

2024 Journal of Hazardous Materials 7 citations
Article Tier 2

Wave-averaged motion of small particles in surface gravity waves: Effect of particle shape on orientation, drift, and dispersion

This study uses mathematical modeling to show that the shape of a small particle — such as a microplastic fragment — determines how it orients itself, drifts, and spreads when carried by ocean surface waves. This matters for predicting where microplastics accumulate in the ocean, since non-spherical fibers and fragments move very differently from spheres under the same wave conditions.

2023 Physical Review Fluids 10 citations
Article Tier 2

Systematic Evaluation of Physical Parameters Affecting the Terminal Settling Velocity of Microplastic Particles in Lakes Using CFD

Researchers used computational fluid dynamics to systematically evaluate how physical parameters including size, shape, density, and surface roughness affect microplastic settling velocity in lakes, finding that particle shape and density are the most influential factors determining residence time.

2022 Frontiers in Environmental Science 25 citations
Article Tier 2

Behavior of Microplastics in Inland Waters: Aggregation, Settlement, and Transport

This review examined how microplastics aggregate, settle, and are transported horizontally in inland waters, covering the influence of particle properties (size, density, shape) and environmental factors (microorganisms, hydraulic conditions, sediment characteristics) on their fate.

2021 Bulletin of Environmental Contamination and Toxicology 154 citations
Article Tier 2

Settling behaviour of irregular-shaped polystyrene microplastics

Researchers studied the settling behavior of irregular-shaped polystyrene microplastics in water, finding that shape significantly affects how fast particles sink. Understanding settling behavior is important for predicting how microplastics distribute vertically in rivers and ocean water columns.

2021 Science & Technology Development Journal - Engineering and Technology 7 citations