We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
On mechanical fragmentation of single-use plastics in the sea swash zone with different types of bottom sediments: Insights from laboratory experiments
Summary
Laboratory experiments simulated wave action and beach conditions to study how four common plastic types mechanically fragment from centimeter-scale pieces into microplastics, with fragmentation rates depending on plastic type and sediment composition. Understanding these fragmentation dynamics helps explain how beach plastic litter generates the microplastic particles found in coastal environments.
Mechanical fragmentation of four commonly used plastics, from 2-cm squares or cubes to microplastics (MPs, <5 mm), is experimentally investigated using a rotating laboratory mixer mimicking the sea swash zone with natural beach sediments (large and small pebbles, granules, sand). Macro-samples were prepared from brittle not-buoyant PS (disposable plates), flexible thin film of LDPE (garbage bags), highly buoyant foamed PS (building insulation sheets), and hard buoyant PP (single-use beverage cups). With a great variety of behaviors of plastics while mixing, coarser sediments (pebbles) have higher fragmentation efficiency than sands (measured as the mass of generated MPs), disregarding sinking/floating or mechanical properties of the samples. It is confirmed that, under swash-like mixing with coarse sediments, the MPs tend to burry below the sediment surface. The obtained relationship between the mass of MPs and the number of items is similar to that for MPs floating at the ocean surface.
Sign in to start a discussion.
More Papers Like This
Secondary Microplastics Generation in the Sea Swash Zone With Coarse Bottom Sediments: Laboratory Experiments
Laboratory experiments in a simulated beach swash zone showed that mechanical abrasion of polypropylene, polyethylene, and polystyrene debris generates secondary microplastic particles in the 0.5-5 mm size range. The study provides direct experimental evidence that wave action on beaches is an active mechanism producing new microplastics from macroplastic debris.
Combined Effects of UV Exposure Duration and Mechanical Abrasion on Microplastic Fragmentation by Polymer Type
Researchers studied how UV exposure duration and mechanical abrasion combine to fragment different plastic types under simulated beach conditions. They found that polypropylene was far more susceptible to fragmentation than polyethylene after UV weathering, while expanded polystyrene broke apart readily even without UV exposure. The experiments showed that a large fraction of fragmented particles were too small to recover, suggesting that significant amounts of nanoplastic are being generated on beaches.
From macroplastic to microplastic: Degradation of high-density polyethylene, polypropylene, and polystyrene in a salt marsh habitat
Researchers subjected high-density polyethylene, polypropylene, and other plastics to simulated environmental degradation and tracked their fragmentation from macro- to microplastic sizes, characterizing surface changes and particle generation rates.
Macro-plastic weathering in a coastal environment: field experiment in Chesapeake Bay, Maryland
Field experiments in Chesapeake Bay tracked how macroplastic items of different polymer types weathered and fragmented over time in a coastal environment. The study found that UV exposure and wave action caused rapid surface degradation and fragmentation, with important implications for how quickly plastic pollution generates secondary microplastics in coastal zones.
Towards Understanding Drivers of Plastic Embrittlement and Fragmentation in Coastal Environments
This review examines the physical and chemical drivers of plastic fragmentation in coastal environments, including UV radiation, mechanical wave action, temperature fluctuations, and oxidation. The authors find that coastal environments produce microplastics faster than open ocean environments due to compounding abiotic stressors, and that fragmentation dynamics shape the size distribution and toxicity profile of coastal plastic pollution.