Adsorptive performance of graphene oxide-activated carbon composite for simultaneous removal of diclofenac sodium and ibuprofen from aqueous solutions in batch mode

Abstract

Graphene oxide-activated carbon (GO–AC) composite with different ratios of GO and AC (0.5/0.5, 0.3/0.7 and 0.1/0.9) were synthesized via direct chemical bonding of them using hydrogen peroxide as a chemical linker and used for selective removal of diclofenac sodium (DCF) and ibuprofen (IBP) from aqueous solutions. The adsorbents' surface morphology, composition, and physicochemical structure of the adsorbents were characterized by FE-SEM, FTIR, BET and XRD analysis. The synthesized composite with a ratio of GO and AC (0.1/0.9) was the most suitable among the synthesized adsorbents for both DCF and IBP adsorption. The optimal working conditions for DCF removal were at pH of 2, contact time of 40 min, initial concentration of 100 mg/L, and temperature of 293 K. For IBP removal, the optimal operating conditions were at pH of 2, contact time of 60 min, initial concentration of 20 mg/L, and temperature of 293 K. The highest adsorption capacities of 0.1/0.9 composite for DCF and IBP were 833.33 and 238.095 mg/g at 298 K, respectively. Isotherm, kinetic, and thermodynamic characteristics were assessed to analyze the adsorption process. The synthesized adsorbent displays high removal efficiency by simple recyclability with low-cost reagent and high selectivity for drug pollutants such as DCF and IBP in single and binary systems.