Comprehensive review of the co-transport of microplastics and suspended sediments in aquatic environments: macroscopic transport and microscopic mechanisms

In recent years, the distribution and transport of microplastics (MPs) in aquatic environments have garnered significant research interest due to their interactions with sediments, which directly influence their migration pathways, deposition patterns, and ecological risks. This study reviews research on the co-migration of suspended sediments (SS) and MPs based on publications from the Web of Science and Engineering Village databases spanning 2011–2025. A co-occurrence network analysis of keywords was conducted using CiteSpace, and the literature was visualized accordingly. The study also investigates the distribution of MPs in sediments within Chinese waters as a case study. The spatiotemporal distribution of MPs is influenced by hydrological conditions (e.g., flow and runoff intensity) and MP properties (e.g., density, shape, polymer type). This paper provides a systematic overview of key physical processes in sedimentary environments, including MP aggregation, settling, burial, and resuspension. Hydrographic conditions, particle concentration, and material properties are identified as the primary factors governing their co-migration. At the microscopic level, interactions between MPs and SS are mainly controlled by van der Waals forces, electrostatic interactions, and covalent bonding. The co-migration of MPs and SS involves multi-mechanistic coupling governed by physical, chemical, and biological processes. This study offers a scientific basis for assessing pollution risks and developing effective management strategies.