We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Migration behaviors of microplastics in sediment-bearing turbulence: Aggregation, settlement, and resuspension
Summary
This study explored how turbulent shear flow affects microplastic aggregation with suspended sediment and the resulting vertical migration behavior. Smaller microplastics aggregated more readily with sediment particles, dramatically increasing their settlement rate and potentially causing secondary pollution when bottom sediments are resuspended by turbulence.
The interaction between microplastics (MPs) and suspended sediment (SS) is important for the environmental fate of MPs. This study explored the interaction of MPs with SS and the vertical migration behavior of MPs in sediment-bearing turbulence. The turbulent shear flow caused MPs to aggregate. This aggregation resulted in a rapid increase in particle size, which peaked when the shear rate was 19.94 s, and then declined with a further increase in the shear rate. Compared to large MPs, small MPs were more prone to aggregation, which formed heterogeneous aggregate MPs-SS in sediment-bearing turbulence. Owing to the formation of heterogeneous aggregates, small MPs had a much higher settlement rate in sediment-bearing turbulence than in sediment-free turbulence. MPs in bottom sediments may resuspend owing to turbulent shear flow acting on sediments, causing secondary pollution. These results provide new insights into the aggregation, settlement, and resuspension behaviors of MPs in natural waters.