Efficient, Geometry-only Prediction of Advection-dominated Particle Transport through Saturated Soils
Year: 2026
Type: preprint
Abstract: The environmental transport of microplastic particles has raised concerns because of their potential ecological and human-health impacts. A particular challenge for experiments on microplastic transport in soils is the fact that soil is a highly complex and non-transparent porous medium. Thus, our knowledge of transport mechanisms of microplastics in soils and related ecological implications is still limited and computational simulations offer an additional possibility to obtain important insights into the physical transport behaviour of microplastics. Yet, direct particle-resolved simulations in realistic soil structures for macroscopic sample sizes remain a computational challenge. We introduce an efficient pore-network model, minD-PNM, that predicts particle breakthrough curves in water-saturated soils using experimental X-ray micro-computed tomography ($μ$CT) pore geometries as the only input. The model combines an approximately $t^{-3}$ pore-scale transit time distribution with a minimum-dissipation partition of multi-inlet-multi-outlet pores, and propagates these distributions through the pore network to predict breakthrough curves. We benchmark minD-PNM against lattice Boltzmann and immersed boundary simulations for small systems, and against microplastic column experiments in quartz sediments for macroscopic sample sizes. In both cases, the predicted breakthrough curves agree well with the corresponding reference data. Because it requires only geometric information, minD-PNM scales to macroscopic sample volumes offering a practical tool for contaminant-hydrology studies of particulate pollutants.
Source: arXiv (Cornell University)
Institutions: University of Bayreuth, University of Cologne
Language: English
Subfield: Environmental Engineering
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
Awards: LinuxCluster zum wissenschaftlichen Hochleistungsrechnen, G3961440842, SFB 1357: MIKROPLASTIK – Gesetzmäßigkeiten der Bildung, des Transports, des physikalischchemischen Verhaltens sowie der biologischen Effekte: Von Modell zu komplexen Systemen als Grundlage neuer Lösungsansätze, G983317151
OpenAlex ID: W7220697643