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61,005 resultsShowing papers similar to Normalized Settling Velocity Governs Short-Range Transport of Atmospheric Microplastics
ClearEffects of Shape and Size on Microplastic Atmospheric Settling Velocity
Researchers measured atmospheric settling and horizontal drift velocities of various microplastic shapes and sizes in controlled settling chambers, providing empirical data needed to improve atmospheric transport models that explain how microplastics reach remote environments.
Experimental investigation of the fallout dynamics of microplastic fragments in wind tunnel: The BURNIA agenda
Wind tunnel experiments were used to measure the settling velocity of airborne microplastic fragments of PET, PVC, and low-density polyethylene, providing the first empirical data to model how plastic particles fall out of the atmosphere.
A new model for the terminal settling velocity of microplastics
A new empirical model for the terminal settling velocity of microplastics was developed and validated using 1,343 experimental measurements covering a range of particle shapes and materials. The model improves predictions of microplastic sedimentation rates, which are critical for understanding how plastic particles are transported and deposited in water bodies.
Gravitational settling of microplastic fibers: experimental results and implications for global transport
This study measured the gravitational settling velocities of microplastic fibers and found that their non-spherical shape causes them to settle much more slowly than spheres of the same volume. Current atmospheric transport models that assume spherical particles significantly underestimate how long fibers remain airborne. These results have important implications for predicting how far microplastic fibers can travel before depositing.
Is transport of microplastics different from that of mineral dust? Results from idealized wind tunnel studies
Researchers conducted wind tunnel experiments to examine the detachment and transport behavior of microplastics ranging from 38 to 125 um in diameter from idealized substrates, comparing their aerodynamic behavior to the well-established literature on mineral dust transport. The study identified key differences in microplastic detachment mechanisms relevant to understanding long-range atmospheric dispersal of plastic particles.
Vertical concentrations gradients and transport of airborne microplastics in wind tunnel experiments
Wind tunnel experiments tracked how tiny airborne microplastic particles (about half a micrometer in diameter) distribute vertically in moving air, finding conditions under which they can remain suspended and travel long distances. These results help explain how microplastics reach remote environments like mountain peaks and Arctic ice, and contribute to models of human inhalation exposure in urban and rural settings.
Is transport of microplastics different from mineral particles? Idealized wind tunnel studies on polyethylene microspheres
Wind tunnel experiments revealed that plastic (polyethylene) microspheres behave differently from mineral dust particles when transported by wind, particularly on hydrophobic surfaces, where plastic particles detach and become airborne more readily. Particle-to-particle collisions were found to both assist and impede detachment. These findings help explain why microplastics are found in remote atmospheric environments and improve models for predicting how far plastic particles can travel through the air from pollution sources.
Twist, turn and encounter: the trajectories of small atmospheric particles unravelled
Experiments and simulations studied how non-spherical solid particles (including microplastics) settle through air, finding unexpectedly complex tumbling and spiraling trajectories even at low speeds. These insights improve predictions of how airborne microplastic particles travel and deposit across landscapes.
Modeling the Gravitational Settling of Microplastic Fibers in the Atmosphere
Researchers developed and applied a model for gravitational settling of microplastic fibers in the atmosphere, examining how fiber shape and size influence atmospheric residence time and deposition patterns to better understand the global atmospheric transport cycle of microplastics.
Terminal Settling Velocity of Cylindrical Rods with Various Geometries Applicable to Atmospheric Microplastics
Researchers measured how the shape of cylindrical microplastic fibers affects their settling speed through air, finding that curved and V-shaped fibers fall significantly faster than straight ones — up to 57% faster for V-shaped rods — which matters for predicting how airborne microplastics disperse in the atmosphere.
Modeling Microplastic Transport in the Marine Environment: Testing Empirical Models of Particle Terminal Sinking Velocity for Irregularly Shaped Particles
Researchers tested multiple drag models for predicting the terminal settling velocity of irregularly shaped microplastic particles in seawater, identifying three high-precision models and demonstrating that settling velocity is largely stable across ocean depths and independent of initial particle velocity, improving the accuracy of marine microplastic transport simulations.
Is plastic dust different from mineral dust? Results from idealized wind tunnel experiments.
Researchers conducted wind tunnel experiments to compare how plastic particles of different sizes detach from flat surfaces in wind compared to mineral dust particles. Plastic particles required higher wind speeds to become airborne than mineral dust of similar size, likely due to shape differences. These findings inform atmospheric transport models for predicting how far and how much microplastic can be carried by wind across the landscape.
A physics-based and orientation-aware method for the direct calculation of the settling speed of prolate spheroidal particles in the atmosphere : theoretical basis and comparison to laboratory and CFL data
Researchers developed a physics-based, orientation-aware method for calculating the settling speed of prolate spheroidal particles such as microplastic fibres in the atmosphere, grounding the approach in theoretical drag and orientation models rather than purely empirical fits and validating it against laboratory and CFD data.
Vertical concentrations gradients and transport of airborne microplastics in wind tunnel experiments
Researchers used a wind tunnel to study the vertical transport and concentration gradients of airborne polystyrene microplastics (0.51 micrometers diameter) injected at different heights under neutral atmospheric stability conditions. Results showed that maximum particle concentrations shifted toward the surface due to gravitational settling, and flux-gradient similarity analysis revealed the conditions necessary for long-range atmospheric microplastic transport.
Settling Velocities of Small Microplastic Fragments and Fibers
Researchers precisely measured the settling speeds of over 4,000 small microplastic particles in water and found that existing prediction models designed for larger microplastics do not work well for these tiny fragments and fibers. The settling speed depends on each particle's size, density, and shape, with the smallest particles sinking extremely slowly. Understanding how quickly microplastics settle in water is important because it determines how far they travel and how long they remain available to be consumed by aquatic organisms that humans may eventually eat.
Long-distance atmospheric transport of microplastic fibers depends on their shapes
Researchers developed a theory-based settling velocity model for microplastic fibers in the atmosphere that accounts for fiber shape and cross-sectional dimensions, finding that correctly characterising flat fibers rather than treating them as cylinders increases estimated mean atmospheric residence time by over 450%, suggesting the ocean is a major source of airborne plastic and that long-range transport is far more efficient than previously thought.
The atmospheric settling of commercially sold microplastics
Researchers measured the gravitational settling velocities of commercially available glitter microplastics (0.1-3 mm nominal diameter) and synthetic fibers (1.2-5 mm length) in air, finding that non-spherical shapes cause complex settling behaviors that deviate substantially from spherical particle models used in atmospheric transport models.
Atmospheric transport of microplastic particles as a function of their size and shape
Researchers investigated the atmospheric transport and settling of microplastic particles as a function of size and shape, implementing a shape-correction parameterization for fiber-shaped particles in an atmospheric transport model to better represent their reduced gravitational settling velocity compared to spheres. The study showed that non-spherical fibers experience greater atmospheric drag, increasing their residence time and transport distance, and that including shape effects improved agreement between model output and ground-based measurements.
A mechanistic approach to evaluating atmospheric deposition of micro- and nanoplastic particles
This study developed a theoretical framework to better understand how microplastic and nanoplastic particles move through the atmosphere and deposit onto land and water surfaces via wet and dry deposition. By drawing on knowledge from how other aerosols like mineral dust behave, the researchers identified key physical processes — including particle size, shape, and density — that govern how far microplastics travel and where they land. The work is important for modeling the global spread of microplastic pollution, including to remote regions far from pollution sources.
Geometric Form and Density Govern Microplastic Particle Kinetics During Aeolian Transport
Scientists studied how tiny plastic particles move through the air and found that they travel faster and farther than natural particles like sand. This means microplastics can spread much more easily through wind to remote areas where people live, including places far from pollution sources. Understanding how these plastics move through the air is important because it helps explain why microplastics are showing up everywhere on Earth, potentially affecting human health through the air we breathe.
Particle properties and environmental factors control atmospheric transport and deposition of micro- and nanoplastics
Researchers built a mathematical model to predict how micro- and nanoplastics travel through the atmosphere, finding that particles around 1 micrometer in diameter and fiber-shaped plastics can remain airborne for weeks and travel long distances. Factors like wind speed, rainfall, and the particles' own shape and density determine whether plastics stay in the air for seconds or spread globally.
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.
Atmospheric transport dynamics of microplastic fibres
Researchers examined the atmospheric transport dynamics of microplastic fibres within boundary layer flows, comparing their motion to mineral grain transport and finding key differences in behaviour that have important implications for modelling the long-range atmospheric dispersal of microplastics to remote and rural locations.
Three-Dimensional Settling Dynamics of Environmental Microplastics
Researchers measured the three-dimensional settling dynamics of environmental microplastic particles in water, including lateral drift, settling paths, and horizontal velocities—dimensions poorly understood beyond simple vertical settling rates. The findings are essential for developing accurate models of how MPs distribute across river channels and water columns.