Kinetic Modeling of Direct Yellow Dye Adsorption onto Graphene Oxide

In this research, graphene oxide nanosheets (GO) was synthesized via oxidation of graphite by Hummers method and it was used for the removal of Direct Yellow 50 (DY50) from aqueous solution. The chemical and crystalline structures of the adsorbent were studied along with influencing parameters (pH, temperature, contact time, adsorbent dosage, and initial dye concentration) on the adsorption process. The results showed that the uptake of DY50 onto GO surface is favored at lower pH values of solution, low temperatures, and higher dye concentrations. The pseudo-first order, pseudo- second order, intraparticle diffusion, Elovich, and fractional power kinetic models have been developed to predict the rate constants of adsorption and equilibrium capacity by non-linear method. Equilibrium adsorption data well fitted with pseudo-first-order kinetic model.