We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Evaluation of the Effects of Particle Characteristics on the Terminal Settling Velocities of Microplastics in Stagnant Waters using CFD
AI summary Read the abstract
This study used computational fluid dynamics to simulate the terminal settling velocities of microplastic particles with different shapes, sizes, and densities in still water. Results showed that particle shape, particularly deviation from a sphere, significantly affects how fast microplastics sink in aquatic systems.
Mismanaged waste leads to inputs of microplastics into the environment and the aquatic system affecting rivers and lakes. The physical properties of microplastic (MP) particles affect their terminal settling velocity (TSV) in the water column and in turn their distribution patterns in aquatic systems. To evaluate the settling behavior and the TSV of MP particles we simulated the settling of a large range of MP particles with regular and irregular shapes in the water column using a computational fluid dynamics (CFD) model. To validate the results returned by our model, we compared CFD findings to the corresponding results obtained by semi-empirical relationships as well as the results from experiments for 120 irregularly shaped MP particles with sizes and densities ranging from 500 to 2000 µm and 1.03 to 1.38 grcm-3, respectively. The CFD results are in good agreement with the results from the laboratory and semi-empirical relationships with a 0.05 difference in the slopes of their linear regressions. In a next step, we defined scenarios to systematically investigate the influence of different particle characteristics such as roundness, density, and volume as well as water temperature on the TSV of regular and irregular MP particles. Our simulations revealed a dominant effect of particle density on the TSV compared to the effects of the other parameters. For example, doubling particle densities increased the TSVs of the MP particles up to 500%, while, doubling their volumes only led to a maximum increase in their TSV of 200%. Increasing the roundness of the MP particles, letting them evolve towards a perfect sphere, increased their TSVs by up to 15%, while seasonal changes in lake water temperatures typical for lakes in temperate climate regions, caused changes in TSVs by up to 32%.
More Papers Like This
Systematic Evaluation of Physical Parameters Affecting the Terminal Settling Velocity of Microplastic Particles in Lakes Using CFD
AI summary Read the abstract
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.
Coupled CFD-DEM modelling to assess settlement velocity and drag coefficient of microplastics
AI summary Read the abstract
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.
Sedimentation of Irregular Shaped Microplastics Under Steady and Dynamic Flow Conditions
AI summary Read the abstract
Researchers conducted experiments to study how irregularly shaped microplastic particles settle under both steady and turbulent water flow conditions, finding that shape significantly affects sinking rates in ways not captured by models designed for spherical particles. Improved understanding of how real-world plastic particle shapes affect transport is needed for accurate environmental fate modeling.
Settling velocity of irregularly shaped microplastics under steady and dynamic flow conditions
AI summary Read the abstract
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.
Settling velocity of microplastic particles having regular and irregular shapes
AI summary Read the abstract
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.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.