Preparation of graphene oxide/chitosan complex and its adsorption properties for heavy metal ions

Abstract

Graphene oxide hydrosol was added dropwise to the surface of chitosan (CS) to successfully obtain graphene oxide/chitosan composite (GC). The composite material was characterized by scanning electron microscopy and X-ray diffraction. The prepared adsorbent was used to simulate the static adsorption of copper, lead, and cadmium ions from 100 mL of 50 mg/L simulated wastewater samples. When the pH of the simulated wastewater is 6, initial dosage is 70 mg, adsorption time is 90 min, and temperature is 20°C; the adsorption capacities for copper, lead, and cadmium are 60.7, 48.7, and 32.3 mg/g, respectively. The adsorption and desorption cycle experiments show that the adsorption capacity of GC for copper ions can reach 86% of the initial adsorption capacity after ten cycles. The adsorption of lead ions on the composite conforms to the Freundlich adsorption isotherm model.

Keywords

• adsorption
• heavy metal ion
• graphene oxide
• chitosan