Enhanced adsorption of perfluorooctanoic acid using functionalized imidazolium iodide ionic liquid-based poly (glycidyl methacrylate)

Per- and polyfluoroalkyl substances (PFASs) are among the emerging pollutants of public health and the environment due to environmental persistence, bioaccumulation, and potential toxicity. Removal of PFAS under mild conditions is a challenge. Therefore, employment of organic functionality immobilized on polymeric sorbents has driven significant attention. Herein, new imidazolium-based ionic liquid (IIL) covalently grafted on poly (glycidyl methacrylate) (PGMA) support was synthesized successfully and characterized by Fourier transform infrared, scanning electron microscope, and thermal gravimetric analysis. The functionalized imidazolium ionic liquid-based PGMA was applied in perfluorooctanoic acid (PFOA) removal from an aqueous solution. The effect of contact time, adsorbent dose, temperature, pH, and counter anions investigated on the extent of adsorption has been investigated. The concentration of PFOA solutions was measured by ethyl violet active substances assay, and equilibrium data were analyzed by Langmuir, Freundlich and Tempkin isotherms. The experimental results have been fitted to Langmuir model at ambient temperature and the maximum monolayer coverage capacity (q_m) was found to be 769.23 mg/g. Also the thermodynamic parameters were obtained, and observed that the adsorption of PFOA onto imidazolium iodide-PGMA was an endothermic and spontaneous process at the temperatures under investigation.