Efficient removal of beta-blockers from water using fluorinated covalent organic polymers: Insights into sigmoidal adsorption behavior and environmental applications

In this research, fluorinated covalent organic polymer (FCOP) was synthesized and evaluated as a novel adsorbent for removing atenolol (ATL) and metoprolol (MTL), two widely prescribed beta-blockers frequently found in water environments. FCOP demonstrated rapid adsorption, achieving removal efficiencies of 67.26 % for MTL and 70.43 % for ATL within just 1 min, relative to the total adsorption at 600 min. The adsorption isotherms exhibited unique sigmoidal behavior, described effectively by the Langmuir-BET model, highlighting initial monolayer adsorption followed by multilayer interactions. The maximum adsorption capacities (q_max) were 98.87 mg/g for ATL and 106.9 mg/g for MTL, with adsorption continuing even beyond apparent equilibrium, indicating persistent adsorption potential. This exceptional performance results from FCOP's fluorine-rich structure, facilitating multiple interactions including electrostatic attraction, hydrophobic effects, and π-π_F interactions. Furthermore, FCOP maintained high efficiency even in complex aqueous environments containing inorganic ions, humic acids, and in real water from the river and sewage treatment plants, underscoring its practical applicability. Given its straightforward one-pot synthesis, cost-effectiveness, and excellent adsorption capabilities, FCOP represents a promising solution for addressing pharmaceutical pollution, providing critical insights into advanced materials for sustainable water purification technologies.