Author(s): Ge Yang; Wenming Zhang

Linked Author(s): Wenming Zhang

Keywords: P microplastic disks; Settling velocity; Trajectory; Acceleration motion

Abstract: The unsteady motion of microplastics (MPs) in the sedimentation process such as the acceleration phase before they reach the terminal settling velocity, was hardly investigated. We studied the behaviors of microplastic (MP) disks in the acceleration phase. The MP disks, ranging from 3 to 5 mm, made from three common polymer types (density ρs = 1.038 g/cm3 - 1.343 g/cm3), are released into the water in five ways and with release angles of 0°, 45° and 90°. The MP disk with release angles of 0° starts to zigzag immediately after release, while the MP disks with release angles of 45° and 90° experience an adjustment phase at first where they adjust to the horizontal position. The adjustment distances in the vertical (Lx) and horizontal (Ly) directions, as well as the maximum vertical settling velocity (Wx, max), are influenced by the MP density, size, release angle and release way. The detailed settling trajectory and velocity were analyzed. The relationships between Lx, Ly, Wx, max and impact factors including MP density, size, shape, crosswise sphericity and release angle were proposed.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0747-cd

Year: 2023