Removal of Ibuprofen from Aqueous Solutions by Using Graphene Oxide@MgO

In this study, a new composite adsorbent, namely magnesium oxide modified graphene oxide (hereafter abbreviated GO@MgO), was prepared for the removal of Ibuprofen (IBU), a non-steroidal anti-inflammatory drug (NSAID) compound. Graphene oxide was modified with MgO to improve its properties. Several factors important for the evolution of the adsorption process were investigated, such as the dose of the adsorbent, the pH, and the initial IBU content, as well as the duration of the procedure and temperature. According to the results obtained, it was found that at pH 3.0 ± 0.1, by applying 0.5 g/L GO@MgO to 100 mg/L IBU, more than 80% was removed, reaching 96.3% with the addition of 1.5 g/L adsorbent in 24 h. After 30 min, the equilibrium was reached (77% removal) by adding 0.5 g/L of GO@MgO. This study proves that GO@MgO is capable of economical and efficient adsorption. The IBU kinetic data followed the pseudo-second-order kinetic model. Langmuir and Freundlich isotherm models were used to interpret the adsorption, but the Freundlich model described the adsorption method more accurately. The positive values of ΔH0 (14.465 kJ/mol) confirm the endothermic nature of the adsorption. Due to the increase of ΔG0 values with temperature, the adsorption of IBU on GO@MgO is considered to be spontaneous.