Related Experiment Video
Updated: Aug 8, 2026
05:31
Sampling, Sorting, and Characterizing Microplastics in Aquatic Environments with High Suspended Sediment Loads and Large Floating Debris
Published on: July 28, 2018
Simulating microplastic dynamics in fluvial networks: A case study of the Irwell-Mersey river system
Nirman Bhagat1, Andrea Marion2, Andrea Bottacin-Busolin2
1Regional Municipality of Halton, 1151 Bronte Rd, Oakville, ON L6M 3L1, Ontario, Canada.
Journal of Contaminant Hydrology
|August 6, 2026
Summary
River floods significantly redistribute microplastics in sediments, with high-flow events controlling mobility. Particle density and river shape determine microplastic accumulation and flushing, impacting contamination levels.
Area of Science:
- Environmental Science
- Hydrology
- Geomorphology
Background:
- Microplastics are persistent contaminants in river sediments.
- Processes governing microplastic storage and redistribution are poorly understood.
Purpose of the Study:
- To investigate microplastic accumulation, mobilisation, and redistribution in rivers using a numerical sediment-transport model.
- To isolate the role of internal river processes on microplastic dynamics.
Main Methods:
- Numerical sediment-transport modeling of microplastic dynamics.
- Simulation of two contrasting rivers in the Irwell-Mersey catchment.
- Exclusion of external inputs to focus on internal river processes.
Main Results:
- Model generated spatial heterogeneity in microplastic contamination.
- Extreme floods caused significant reductions in microplastic contamination.
- High-flow events control microplastic mobility, driving scour and downstream transfer.
- Particle density modulates microplastic mobilisation; low-density particles are more mobile.
- River hydraulics, not slope, explain differences between studied rivers.
Conclusions:
- High-flow events are the primary drivers of microplastic redistribution in river sediments.
- Particle density and river morphology interact to control microplastic retention and transport.
- The model provides a quantitative framework for interpreting microplastic monitoring data and assessing impacts of hydrological extremes.
Related Concept Videos
01:30Typical Model Studies
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
01:24Rapidly Varying Flow
Rapidly varying flow (RVF) in open channels is characterized by abrupt changes in flow depth over a short distance, with the rate of depth change relative to distance often approaching unity. These flows are inherently complex due to their transient and multi-dimensional nature, making exact analysis difficult. However, approximate solutions using simplified models provide valuable insights into their behavior.Key Features of Rapidly Varying FlowRVF is commonly observed in scenarios involving...
01:21Design Example: Creating a Hydraulic Model of a Dam Spillway
Scaled hydraulic models of dam spillways provide a practical way to replicate and study the intricate flow dynamics of these structures. Often built to a 1:15 ratio, these models allow for observing critical water behavior, such as velocity distribution, flow patterns, and energy dissipation.