Abstract
The graphene oxides were applied as adsorbents to remove Sr-90(II) ions from aqueous solutions under different experimental conditions. The results showed that Sr-90(II) sorption was mainly dominated by ion exchange and outer-sphere surface complexation. The maximum sorption capacity (C (smas)) was calculated to be 3.84 x 10(-4) mol/g at pH 5.8 and 20 A degrees C, which was much higher than that of Sr-90(II) on other today's materials. The thermodynamic parameters suggested that the sorption was an endothermic and spontaneous process. The theoretical calculation results indicated that COH and COC groups contributed to the coordination of Sr(II) ions.