Adsorption and kinetic desorption study of Eu152+154(III) on multiwall carbon nanotubes from aqueous solution by using chelating resin and XPS methods

Multiwall carbon nanotubes (MWCNTs) have been pretreated with HNO3 and used for the adsorption of radionuclide Eu152+154(III) from aqueous solutions. The effects of pH (2-12), ionic strength (0.01 M and 0.1 M NaClO4) and radionuclide Eu152+154(III) solution concentrations (10(-8)-10(-5) mol/L) on the adsorption of Eu152+154(III) on MWCNTs were investigated. The experiments were carried out at 25 +/- 2 degrees C and under atmosphere conditions. Adsorption of Eu152+154(III) on MWCNTs increases significantly with increasing pH at pH < 6, and over 96% Eu152+154(III) are adsorbed on MWCNTs at pH > 6. Strong surface complexation and/or chemisorptions are considered as the main adsorption mechanism. The sorption was also characterized by using high resolution XPS spectra. The results show that MWCNTs can be a promising candidate of adsorbent for preconcentration of lanthanides from large volumes in radioactive nuclear waste management.