Removal of cadmium (II) from aqueous solution by graphene oxid

Heavy metal ions are one of the principal contamination source and cause of difficulties in wastewater processing that requires being eliminated before discharging into the eco-system. Adsorption of cadmium (II) from an aqueous solution by graphene oxide has been considered. Recently, graphene oxide (GO) has taken a large amount of attention because of high mechanical strength and appropriate surface area that has provided to apply as strengthened materials, various oxygen functional groups on its surface and π-electron system. In this investigation, graphene oxide was employed as an effective and proper adsorbent for separating the cadmium (II) from aqueous solution. TEM, Raman, FT-IR, and SEM tests have been used for characterizing the graphene oxide. In the adsorption process, initial concentrations of aqueous solution examined from 20 to 100 mg/l; pH and contact time were investigated from 3 to 8 and 5 to 100 minutes respectively. Adsorption isotherm obeyed Langmuir, Freundlich, and Temkin that the maximum cadmium adsorption capacity has been taken from Langmuir fitting with 135.14 mg/g. Also, the kinetic considerations explained that the adsorption manner followed the pseudo-second-order kinetic model with R2. Thermodynamic investigations and parameters show the exothermic and spontaneous of adsorption