Adsorption of Aniline from Aqueous System by Highly Fluorinated Polymers of Intrinsic Microporosity (PIM-2)

Polymers of Intrinsic Microporosity (PIMs) are documented as suitable materials for organic adsorption applications. Intrinsic porous structure along with a solution-processability behaviour make them attractive for the adsorption of organic contaminants from water. In this research, PIM-2 powder was synthesised and the exploitation of PIM-2 for aniline removal was studied using a batch adsorption process. The effect of several variables were explored including initial aniline concentration, adsorption time and temperature. Adsorption reached the equilibrium after five hours and experimental adsorption capacity (qe, exp) was found as 79.7 mg g-1 for aniline at pH 6 and 298K. Isotherm (Langmuir, Freundlich and Liu) and kinetic models (pseudo first order and pseudo second order) and elovich model were applied using non-linear regression analysis. In addition, various errors analysis approaches were used to determine the most appropriate isotherm and kinetic models. Pseudo second order model and Liu isotherm fitted well for aniline adsorption. Maximum adsorption capacity (qm) were computed as 82.4 mg g-1 for aniline at pH 6 and 298 K based on the Liu adsorption model. Thermodynamic studies revealed that the adsorption process was physical, spontaneous and exothermic.