期刊
SCIENCE OF THE TOTAL ENVIRONMENT
卷 904, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.scitotenv.2023.167256
关键词
Microplastic infiltration; Microplastic retention; Particles properties; Hyporheic zone; Porous media; Riverbed sediment
This study investigates the impact of different sediment size layers on the mobility of microplastics (MPs) in sediment media. A model is provided to predict the maximum infiltration depth of MPs, highlighting the importance of considering the geometrical and hydrodynamic aspects of riverbed sediment layers to better understand MP transport in freshwater environments.
Several studies focused on the role of rivers as vectors of microplastics (MPs) towards the sea. It is well known that during their path through the fluvial environment, MPs interact with riverbed sediments; however, the main factors impacting the mobility of MPs within the upper part of the hyporheic zone are not clear yet. The present work investigates the role of different sediment size layers in affecting the mobility of the most common MP (Polyethylene terephthalate - PET - spheres, PET 3D-ellipsoids, polystyrene - PS -fragments and polyamide - PA - fibers) within sediment porous media under different hydraulic loads (HL) and time scales (t) conditions. Results indicated the relationship between the characteristic MP diameter and that of the grains as the main parameter for the MP infiltration into the sediment layer. The maximum infiltration depth was found to not depend on HL and t. However, HL was able to influence the percentage of MPs penetrating the superficial layer and their distribution within the first 10-15 cm of the sediment layer. None of the MPs were found at depths >20-25 cm, where only PET spheres were detected. Starting from the suffusion theory, a model able to predict the MP maximum infiltration depth in the range of parameter values was provided.The outcome indicates the importance of considering geometrical and hydrodynamic aspects of the riverbed sediment layer to better characterize the spatial and temporal scales of MP transport in freshwater environments.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据