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Papers
61,005 resultsShowing papers similar to Improving predictions of microplastic incipient motion through shields parameter modifications
ClearExperimental Study on the Incipient Motion of Microplastic Particles with Different Shapes, Sizes, and Densities on a Live Sediment Bed
Researchers experimentally determined the conditions under which 65 groups of microplastic particles of varying shapes, sizes, and densities begin to move on a sediment bed, finding that after accounting for friction differences and hiding effects, microplastic motion follows the classical Shields curve used for natural sediment transport.
Shields Diagram and the Incipient Motion of Microplastic Particles
Researchers conducted flume experiments to determine the conditions under which different shapes and sizes of microplastic particles begin to move along a river or ocean bottom, testing spheres, cylinders, disks, cubes, fibers, and irregular particles. They developed a new framework that accounts for differences in friction, surface roughness, and sheltering effects to predict when microplastics start to be transported. For the first time, the study reconciles microplastic movement behavior with the classical Shields diagram used in sediment transport science.
Incipient Motion of Exposed Microplastics in an Open-Channel Flow
Researchers experimentally determined the conditions needed to initiate microplastic movement in open-channel water flows, finding that standard sediment transport thresholds do not apply to microplastics and proposing a new predictive formula that reduces error from 55.6% to 12.3%.
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.
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.
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.
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.
Understanding how sediment movement affects microplastic deposition in sandy streambeds: A modeling study.
Researchers used a numerical model of flow and particle transport in moving streambed sediment to quantify how streambed motion affects microplastic deposition and accumulation, running simulations across streamwater velocities of 0.1-0.5 m/s and varying median grain sizes to examine MPs of all sizes and densities.
Analysis of hydraulic conditions considering the influence of particle shape
This review article examined how particle shape influences fluid dynamics and sediment transport across various engineering and environmental contexts. Understanding particle shape effects is relevant to predicting how microplastics of different shapes move and settle in aquatic environments.
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.
Investigation of the Sheltering Effects on the Mobilization of Microplastics in Open-Channel Flow
Researchers investigated how bed grain sheltering affects microplastic mobilization in open-channel flow, developing improved formulas for predicting the critical shear stress needed to move microplastic particles of various materials and densities.
Parameterization of microplastic-sediment aggregation for improved fate modelling
Researchers developed parameterisation for microplastic-sediment aggregation (MSA) to improve fate modelling of microplastics in rivers and estuaries, using laboratory experiments to quantify how suspended sediment aggregation with microplastics forms larger, denser flocs with increased settling velocities. The parameterisation was incorporated into numerical transport models to better predict microplastic sinks in aquatic environments.
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.
Bedload transport rates of microplastics on natural sediments under open channel flow: The role of exposure in acceleration
Researchers developed a new model for predicting how microplastics are transported as bedload in rivers, combining computational fluid dynamics with laboratory experiments. They found that exposed microplastics on the sediment surface move at higher transport rates than natural sediment particles of similar size, potentially spreading contamination over wider areas. The model provides a practical tool for engineers assessing how microplastic pollution disperses through waterway systems.
Sedimentation of microplastics interacting with sediment
Researchers conducted laboratory settling velocity experiments for 12 different microplastic types with varying shapes in both clear and turbid water, finding that the simultaneous presence of suspended sediments significantly alters MP settling behaviour in ways not captured by existing models that assume clean water conditions.
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.
Flume experiments on transport and deposition behavior of microplastics in sediment bed environments
Researchers ran 42 flume experiments with three model sediments and spherical microplastics of varying size and density, finding that deposition depth is governed by sediment porosity and the grain-to-particle diameter ratio, while transport is primarily controlled by particle density and initial placement, providing data to improve MP mass balance models.
Parameterization of microplastic-sediment aggregation for improved fate modelling
Researchers developed parameterization for microplastic-sediment aggregation (MSA) processes to improve numerical fate models predicting microplastic transport and accumulation in rivers and estuaries. The work addressed how suspended sediment flocculates with microplastics to form composite aggregates, altering settling velocities and identifying key deposition zones.
Experimental study on parameterizing microplastic-sediment aggregation
Researchers conducted laboratory flocculation experiments to parameterize microplastic-sediment aggregation, testing fibers, fragments, and spheres of varying sizes and densities to characterize how microplastics and sediment form flocs with enhanced settling velocity, with the goal of improving numerical transport models of microplastic fate in rivers and estuaries.
Longitudinal and Vertical Transport of Microplastic Within Sediment in Rivers and Transitional Water Environments
Researchers investigated the longitudinal and vertical transport of microplastics within sediments in rivers and transitional water environments, developing models to quantify how sediment presence affects microplastic mobility and their transport toward coastal areas.
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.
Effects of Microplastic-Sediment Interactions on Microplastics Dispersion in the Gironde Estuary: A Modelling Approach
Researchers developed a hydrodynamic model to investigate how microplastic-sediment interactions influence the dispersion and transport of microplastics within the Gironde Estuary. The modeling approach demonstrated that sediment dynamics significantly affect microplastic fate, altering predicted spatial distributions compared to models that ignore particle-sediment interactions.
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.
Importance of the water-sediment bed interactions in simulating microplastic particles in an estuarine system
This study examined the importance of modeling water-sediment bed interactions when simulating microplastic particle transport in rivers and coastal waters, finding that ignoring bed exchange processes significantly underestimates sediment accumulation of microplastics. Incorporating bed interaction improved model accuracy for predicting microplastic fate.