Transport Mechanics of Microplastic Fibers in a Porous Media Model
Abstract
Microplastic Fibers (MPF) are potential emerging contaminants due to harmful capabilities to both humans and the environment. The presence of microplastics in diverse settings around the world has been confirmed and it has been shown that the largest fraction of microplastics by volume are MPFs, but questions of how they got there and, more importantly, where they are going have not been addressed. It is expected that terrestrial and aquatic soils are known to be the largest sinks for MPFs, but the specific mechanisms of MPF transport through the environment are largely unknown. Our research focuses on developing an understanding of the dynamics of MPF movement/transport in porous media. An intermediate scale (50cm by 20cm) "meso-model" of a periodic porous media was used to conduct laboratory experiments of MPF transport. MPF were added to a steady-state flow through the flow cell water that passed through the meso-model and their trajectories were captured using an HD video camera. The videos were analyzed using Fiji (ImageJ) software and MATLAB scripts allowing a dataset of their trajectories to be created. Three different lengths of fibers (5, 10, and 15mm) were evaluated independently under three different discharges, for nine total configurations. The results showed that the longer fibers flex in the shape of a "C" in the narrow sections of the model but later return to a straight line. The smaller fibers traveled as a rigid straight fiber, and the results suggest that MPF will move as a straight rigid fiber as well. The findings offer unique insights into the transport mechanisms and features of MPF migration, which can lead to better models to describe their transport in the environment and better inform environmental policy.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H55C..54D