HOW HEAVY METALS INFLUENCE MICROPLASTIC DEGRADATION: UV ABSORPTION AND PHOTOREACTIVITY OF PS-FE₃O₄ COMPOSITES

Plastic pollution, particularly microplastics (MPs), presents a severe environmental risk due to the persistence, small size, and ability of plastics to coexist with harmful impurities. Of all MPs, polystyrene microplastics (PSMPs) are particularly noteworthy due to their large surface area, photoreactivity, and ability to last in the environment for long periods. This study investigates the role played by the interaction of heavy metals, especially ironoxide (Fe₃O₄), in the ultraviolet (UV) absorption and photoreactivity of PSMPs. Accordingly, the PSMPs' absorption coefficient was investigated using the UV–visible spectrometry under various concentrations and under the presence of Fe₃O₄. The findings showed that higher PSMP concentrations are typified by higher UV absorption, with the maximum occurring at 295 nm. Further, the presence of Fe₃O₄ enhanced the light absorption and thus indicates that various optical and surface characteristics can influence the pathways to degradation. The study emphasizes the possibility that heavy metals can alter the behavior of the MPs in the environment to influence photochemical stability and ecological implications. Finally, the study also uncovers more information about the mechanisms to degrade MPs and informs future research to tackle pollution control measures.