Ibuprofen Adsorption on Activated Carbon: Thermodynamic and Kinetic Investigation via the Adsorption Dynamic Intraparticle Model (ADIM)

The adsorption efficiency of commercial activated carbon toward ibuprofen (IBU) was investigated and described using the adsorption dynamic intraparticle model (ADIM). Although the adsorption capacity of activated carbon has been widely studied, the kinetic models used in the literature are simplified, treating adsorption kinetics with pseudo-kinetic approaches. In this paper, a realistic model is proposed, quantitatively describing the influence of the main operation parameters on the adsorption kinetics and thermodynamics. The thermodynamic data were interpreted successfully with the Freundlich isotherm, deriving an endothermic adsorption mechanism. The system was found to be dominated by the intraparticle diffusion regime, and the collected data allowed the determination of the surface activation energy (ES = 60 ± 7 kJ/mol) and the fluid–solid apparent activation energy (EA = 6 ± 1 kJ/mol). The obtained parameters will be used to design adsorption columns, allowing the scale-up of the process.