▎ 摘　　要

In this study, graphene oxide (GO) adsorbent was prepared from commercial graphite powder and characterized using a variety of analytical methods, including X-ray diffraction, X-ray photoelec-tron spectroscopy, field-emission scanning electron microscopy, Fourier-transform infrared spec-troscopy, zeta potential, dynamic light scattering and Brunauer-Emmett-Teller analysis. Batch experiments were conducted to investigate the effect of pH, adsorbent dosage, contact time and metal ions concentrations for adsorptive removal of Cu(II) and Cd(II) ions from aqueous solu-tions. The kinetics, adsorption isotherms, and thermodynamics were studied to determine the adsorption mechanism. The results showed that at pH higher than 3.5 (pHzpc), carboxyl group of GO was deprotonated to make the surface negatively charged, which was advantageous for metal ions adsorption. It was also evident that the optimum pH for removal of Cu(II) was 5.0, while that of Cd(II) was 7.0. The adsorption processes of Cu(II) and Cd(II) followed both the Langmuir and Freundlich isotherms, indicating complex nature of the adsorption processes. The maximum adsorp-tion capacities (qmax) of GO for Cu(II) and Cd(II) calculated from Langmuir isotherms were 193.05 and 231.45 mg/g, respectively. The kinetics studies showed that adsorption processes for both the metal ions followed pseudo-second-order reaction model. Thermodynamic investigations revealed the adsorption process as exothermic and spontaneous at room temperature. Regeneration and reuse of spent adsorbents were also studied and found that regenerated GO demonstrated lower adsorption capacities compared to the fresh GO.