Adsorption of Per- and Polyfluoroalkyl Substances (PFASs) on Granular Activated Carbon: A Column Study Abstract The research investigates the water treatment capabilities of fixed-bed granular activated carbon (GAC) columns for removing perfluorobutanoic acid (PFBA), perfluorobutanesulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) from water. PFASs are considered emerging pollutants because they have been widely used and persist in the environment while posing risks to ecosystems and human health. The research evaluates chemical adsorption at low environmental concentrations through simulations of real-world contamination to address increasing regulatory focus and drinking water PFAS occurrences. The research starts by reviewing PFAS characteristics and their health and environmental impacts as well as global drinking water regulatory limits and existing treatment solutions.