No abstract

This research was aimed to study the adsorption capacity and removal of alizarin Red S (ARS) dye using amino-functionalized graphene oxide (NH 2 -GO) as an adsorbent in the presence of CTAB. The optimum conditions were consisted of 100 mg/L initial concentration of ARS with 0.015 g adsorbent at solution pH 2.0. The adsorption equilibrium was completely reached within 60 min. at 28°C. The maximum adsorption capacity of NH 2 -GO for ARS in the presence of CTAB (0.6 mM) was 135.1 mg/g, about three times higher than that of NH 2 -GO (42.0 mg/g) in the absence of CTAB. The adsorption kinetics well fitted using a pseudo second-order kinetic model. The intraparticle diffusion model obtained clearly defined its rate-limiting step. Changes in free energy, enthalpy and entropy were also evaluated. The overall adsorption process was endothermic reaction. The adsorption isotherm for NH 2 -GO in the presence of CTAB better fit with Langmuirn model. It is, therefore, evident that the synergic effect of CTAB enhances the adsorption capacity and removal of ARS via their electrostatic interactions among the three reacting components in the adsorption reaction system.