Adsorption behavior of cross-linked chitosan modified by graphene oxide for Cu(II) removal

Cross-linked chitosan(CS), cross-linked chitosan/graphene(CS/RGO(10)) and cross-linked chitosan/graphene oxide(CS/GO(10)) were prepared as adsorbents for Cu(II). The effects of pH, contact time, adsorbent dosage and initial concentration of Cu(II) on the adsorbing abilities of CS, CS/RGO(10) and CS/GO(10) to Cu(II) were investigated. The results demonstrate that the adsorption capacities of CS/GO(10) and CS/RGO(10) are greater than that of CS, especially at pH 5.0 and the adsorption capacities are 202.5, 150 and 137.5 mg/g, respectively. Their behaviors obey the Freundlich isotherm model very well. Additionally, CS/GO(10) has the shortest time to achieve adsorption equilibrium among them and can be used as a perspective adsorbent for Cu(II).