We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Suspended sediments mediate microplastic sedimentation in unidirectional flows
AI summary Read the abstract
Researchers found that suspended sediments in water significantly increase microplastic sedimentation rates, with higher sediment concentrations driving greater downward transport of microplastics and creating differential settling patterns based on polymer type.
Microplastic particles (MP) are an emerging contaminant threatening many aquatic systems. Because of the sharp increase in plastic manufacture, the concentration of MP in natural ecosystems has grown dramatically. While it is known that when MP enter aquatic ecosystems they are transported and dispersed via different mechanisms (currents, waves, turbulence), the processes involved are still poorly understood. In the current study, the transport of MP by a unidirectional flow has been investigated in a laboratory flume. MP enter the system through a plume that can (or not) have suspended sediment. The interaction between MP and sediment was studied for three different MP particle types (Polyamide (PA) and Polyvinyl Chloride (PVC) fragments, and Polyethylene Terephthalate (PET) fibers), and four different sediment concentrations (0 g/l, 15 g/l, 30 g/l and 45 g/l). In all cases, sediment increased the vertical transport of MP to the bottom. The greater the sediment concentration, the greater the downward flux of MP. Sediment particles scavenged PA fragments downwards at the highest rate, followed by PET fibers and finally PVC fragments. These results indicate that a sediment particle-laden plume carrying MP may induce a differential settling of MP as they are advected. The scavenging of MP by sediments may result in sedimentation segregated patterns, with MP being found at shorter distances than expected for the case without sediment, therefore increasing the presence of MP near their contaminant sources.
More Papers Like This
Transport and sedimentation of microplastics by turbidity currents: Dependence on suspended sediment concentration and grain size
AI summary Read the abstract
Researchers used laboratory experiments to study how turbidity currents, underwater flows of sediment-laden water, transport and deposit microplastics on the ocean floor. They found that higher sediment concentrations carried microplastics farther, and finer sediment grains enhanced transport distances compared to coarser ones. The findings suggest that both the properties of the sediment flow and the shape and density of microplastic particles play important roles in determining where plastics end up in marine sediments.
Sedimentation of microplastics interacting with sediment
AI summary Read the abstract
Researchers conducted laboratory settling velocity experiments for 12 different microplastic types with varying shapes in both clear and turbid water, finding that the simultaneous presence of suspended sediments significantly alters MP settling behaviour in ways not captured by existing models that assume clean water conditions.
Microplastics Settling in Turbid Water: Impacts of Sediments-Induced Flow Patterns on Particle Deposition Rates
AI summary Read the abstract
Researchers studied how suspended natural sediments in turbid water affect the settling rates of microplastics. They found that the presence of fine clay and silt particles significantly increased microplastic deposition rates by creating downward flow patterns that drag the plastics along. The findings suggest that in naturally murky waters, microplastics may settle to the bottom faster than previously assumed, potentially concentrating pollution in sediment layers.
Settling velocities of microplastics with different shapes in sediment-water mixtures
AI summary Read the abstract
Researchers studied how the shape of microplastic particles affects how quickly they sink in water containing suspended sediment. They found that fibers and films settle much more slowly than fragments and pellets, and that sediment in the water significantly slows the settling of all microplastic types. These findings are important for predicting where microplastics accumulate in lakes, rivers, and oceans.
Different microplastics versus different bottom sediments: transport and accumulation pattern in the open-channel flow experiments
AI summary Read the abstract
Researchers conducted open-channel flume experiments with different microplastic types and bottom sediments to study how particle properties and flow conditions determine where microplastics accumulate or are resuspended. The results show that both plastic particle characteristics and the nature of the underlying sediment influence microplastic transport and deposition behavior in rivers.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.