Data for The hyporheic exchange of microplastics

A laboratory scale erosimeter was utilized in combination with fluorometric techniques to quantify the dispersion of 3D-pore scale stained microplastics across the hyporheic zone. Rhodamine WT dye, Polypropylene (PP), polyethylene (PE), and polymethyl methacrylate (PMMA) were well-mixed within the riverbed and individually tested using solute transport theory for three sediment diameters and five bed shear velocities (u_*) found in the natural environment.

Effective dispersion coefficients for solutes significantly differed from that of PE and PMMA in most cases, where a limit as to how slow they could disperse was observed and a method for predicting polymer dispersion was proposed. When u_* ≥ 0.0304 m/s, PMMA followed the same pathways as solutes and solute transport models were successfully implemented to predict its fate. PP near the riverbed interface ascended to the surface but flocculation and aggregation deeper in the riverbed prevented dispersion calculations.