Size-dependent adsorption of waterborne Benzophenone-3 on microplastics and its desorption under simulated gastrointestinal conditions

Microplastics (MPs) are global pollutants with heightened environmental and health concerns in recent years because of their worldwide distribution across aquatic environments, ability to load chemical contaminants and the potential for ingestion by animals, including human. In this study, three commonly used and environmentally detected plastics, i.e. polystyrene, polyethylene, polypropylene with sizes of 550, 250 and 75 mu m, plus two submicron-sized polystyrene microplastics (5 and 0.5 mu m) were assessed as solid adsorbents for a prevalent UV filter, benzophenone-3 (BP-3). The affinity and process of adsorption exhibited differentials among different sizes and types of MPs. Apparent desorption of BP-3 from MPs under simulated gastrointestinal conditions was not significantly enhanced, which might be due to the presence of the enzyme proteins, indicating potential risk of the contaminants carried by MPs. The desorption of BP-3 from MPs was affected by the size, type of MPs and the components of the gastrointestinal fluid.

Automated summary

Microplastics are global pollutants of concern due to their distribution in aquatic environments and ability to carry chemical contaminants. This study evaluated the adsorption of a prevalent UV filter, benzophenone-3, by different sizes and types of microplastics, showing variations in affinity and adsorption processes. Desorption of benzophenone-3 from microplastics was not significantly enhanced under gastrointestinal conditions, indicating potential risks associated with the contaminants carried by microplastics.