Sequestering a non-steroidal anti-inflammatory drug using modified orange peels

Abstract

This study investigates the sorption of a non-steroidal anti-inflammatory drug, ibuprofen, (IBP) using acid activated carbon prepared from orange peel (OPA). OPA was characterized via the use of Fourier transform infrared and scanning electron microscopy techniques. Four isotherm models were utilized to assess the adsorption data: Langmuir, Freundlich, Temkin, and Dubinin–Raduskevich, respectively. It was established that the IBP adsorption onto OPA fitted Langmuir isotherm model most. The optimum monolayer adsorption capacity of OPA was 49.30 mg/g at 50 °C. The adsorption data was subjected to kinetic test using pseudo-first-order and pseudo-second-order, Elovich, and intraparticle diffusion models. The sorption process was best described by pseudo-second-order kinetic model. The mean heat of adsorption, Ea at all temperatures studied was < 8.00 kJmol−1, signifying that the sorption mechanism is physisorption. Thermodynamic study reveals that the adsorption is spontaneous and exothermic. OPA was established to be a viable and effective adsorbent for the sorption of IBP from aqueous medium.