Simultaneous removal of ibuprofen and bisphenol A from aqueous solution by an enhanced cross-linked activated carbon and reduced graphene oxide composite

Abstract

Reduced graphene oxide-modified activated carbon (RGO/AC) composites are promising materials for organic micropollutant removal from aqueous systems. However, the complex preparation processes and usage of toxic chemicals limit their applications. Here, several green cross-linking reagents, such as an extract solution (ES) originating from fermented tubers and cereal wastes, are developed to enhance the cross-linking of AC and RGO. The reactivity of RGO/AC composites was evaluated for bisphenol A (BPA) and ibuprofen (IBP) adsorption from an aqueous solution in single and binary systems. The cross-linking speed and degree for AC and RGO by ES originating from fermented cassava (RGO/AC1) and wheat residues (RGO/AC2) are better than those obtained for natural ES. Characterization results show that the specific surface area of the RGO/AC composites increases with the cross-linking phenomenon. The RGO/AC composites show a higher BPA and IBP removal efficiency and capability than pristine AC. Moreover, the adsorption competence of BPA and IPB on the surface of RGO/AC composites in the binary system was low. The adsorption of BPA and IBP by AC/RGO is dominated by pseudo-second-order kinetics and Freundlich isotherms in both single and binary systems. Hydrophobic and electrostatic interactions are dominant between BPA, IBP molecules, and adsorbents.