LAUSR

Abstract Ibuprofen (IBU) is one of the most commonly used nonsteroidal anti-inflammatory drugs in the world, and is found in abundance in wastewater. This study aims to adsorb IBU from wastewater using O-carboxymethyl-N-laurylchitosan/γ-Fe 2 O 3 (OCh-LM) adsorbents. The adsorption process was carried out in batches, and the effect of adsorption variables was investigated. Langmuir, Freundlich, and Sips isotherms were applied to the equilibrium data. The pseudo-first-order kinetic model, pseudo-second-order kinetic model, and intra-particle diffusion model, were used to determine the adsorption mechanisms. The maximum adsorption capacities of the adsorbents from the Sips isotherm were found to be 395 mg/g at 25 °C and pH 7.0. The regression results showed that the adsorption kinetics was most accurately represented by the pseudo-second-order. Desorption experiments indicated that regeneration of the adsorbents can be performed using ethanol. The response surface methodology (RSM) based on the central composite design (CCD) was successfully applied to the optimization of IBU adsorption. Three independent variables were investigated: initial pH, IBU concentration, and adsorbent. Analysis of variance (ANOVA) of the quadratic model suggested that the predicted values were in good agreement with the experimental data. According to the data from the present work, it is concluded that the OCh-LM can be used as an adsorbent for removal of IBU from aqueous solutions.