Study of adsorption behaviors of diclofenac on the magnetic graphene oxide surface: Isotherms and kinetic

Graphene oxide nanostructure (GO) was synthetized by Humer method [1]. Then the synthetized GO nanoparticles were magnetized and the magnetic graphene oxide (MGO) was characterized by XRD, IR and SEM analysis. Diclofenac is a nonsteroidal anti-inflammatory drug and used to treat mild to moderate pain, or signs and symptoms of osteoarthritis or rheumatoid arthritis. So a large extent of DCF or its metabolits are delivered to the invironmental. The adsorption behaviors of DCF were investigated on the surface of MGO as a sorbent. The different parameters affecting the adsorption process including: MGO dosage, contact time, DCF concentration, and pH were studied in deatails. The MGO adsorbent involves ‘‘oxygen-containing functional groups’’ such as -COOH, which exhibit negative charges over a wide range of pH values (pH 3–11). Electrostatic repulsion occurred between dissociated DCF and the more negatively charged MGO at basic pH ( pKa) [2] and decrease the adsorption effeciency. The results at the optimum conditions showed the great affinity of the MGO toward the DCF and the maximum adsorption capacity was found to be 37.04 mg g-1. The thermodynamic and kinetic confirm spontaneous and exothermic nature of adsorption process and dominatron of pseudo-second-order kinetic model.