Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals characterized by their persistent carbon-fluorine bonds, which make them highly resistant to degradation. PFAS are widely used in the production of goods due to their water-, oil-, and grease-resistant properties. Over time, PFAS can leach from these products, accumulating in soil and water. Studies have shown that PFAS exposure, through ingestion or contact, can have adverse effects on human health. PFAS interacts with soil particles via adsorption, binding to sediment surfaces. Microplastics, another pervasive pollutant, are similarly prevalent in manufacturing due to their lightweight, durable, and moisture-resistant properties. Over time, plastics degrade into microplastics (MPs) —particles smaller than 0.5 mm—which often end up in water bodies and soil. MPs have also been linked to harmful effects on human health through contaminated water, food, and plastic use. Although both PFAS and MPs are recognized as toxic pollutants, little is known about the consequences of their interactions in sediment. This research investigates the adsorption interactions between PFAS, MPs, and sediment. To explore this, 150 µm diameter MP beads were aged in an aquatic mesocosm for one year to observe chemical and physical modifications. Three sediment conditions were tested: pristine MPs in sediment, aged MPs in sediment, and sediment without MPs. Six of the most common PFAS were evaluated at concentrations ranging from 0.5 µg/L to 50 µg/L. Initial results indicate that aged MPs absorb more PFAS than pristine MPs due to an increase in oxygenated functional groups formed during aging. Understanding these surficial transformations is critical for advancing MP research and can inform future studies on MP remediation and adsorption mechanisms.