A renewable, sustainable and low-cost adsorbent for ibuprofen removal

Abstract Adsorption efficiency of acid-modified kola nut husk (KNHA) as a non-conventional adsorbent for the sorption of Ibuprofen from aqueous media was investigated in this study. The raw and modified samples were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, electron dispersive X-ray spectroscopy pH, and Boehm titration techniques respectively. Adsorption parameters such as pH effect, adsorbate concentration, contact time, and solution temperature were studied. The amount of Ibuprofen uptake was observed to increase with a corresponding increase in adsorption operational parameters. The kinetic data was found to best fit the pseudo-second-order kinetic model. Isotherm adsorption models of Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich were utilized to analyze the adsorption data. The Langmuir isotherm model showed the best fit for experimental data with a maximum monolayer adsorption capacity of 39.22 mg/g. The values of Gibbs free energy change were negative (−164.48 to −64.045.4 kJ/mol) suggesting that the process of ibuprofen adsorption onto KNHA was spontaneous. The positive value of standard enthalpy change (+34.203 kJ/mol) suggests that the process of ibuprofen adsorption was endothermic. KNHA adsorbent was found to be efficient and viable for the uptake of ibuprofen from aqueous medium. Hence, adsorbent prepared from kola nut husk waste has proved to be effective for the adsorptive uptake of Ibuprofen from aqueous media.