Effect of hydroxylated fullerene on U(VI) Adsorption onto oxidized multi-walled carbon nanotubes

Herein, hydroxylated fullerene (C60(OH)n) was chosen as the third phase to investigate its impact on U(VI) adsorption onto carbon nanotubes. The results showed that the drastic effect of C60(OH)n on U(VI) adsorption of oMWCNTs was not significant at low concentration of C60(OH)n, whereas a negative effect was observed at higher concentration. The adsorption of U(VI) onto oMWCNTs was enhanced with increasing pH values at pH < 6, but decreased after pH reached 6. The main mechanism may be the adsorbed Cu(II) on oMWCNTs is 'squeezed' down to the solution by the adsorption of C60(OH)n onto oMWCNTs. The double sorption site model was applied to simulate the adsorption isotherms of U(VI) in the presence of C60(OH)n and fitted the experimental data well. This provides reference for studying the interactions between carbon nanomaterials and radionuclide in various conditions of natural environment. Meanwhile, it also brings theoretical basis for studying the biological safety problems caused by multi-component environment pollution. (author)