The adsorption of Eu(III) on carbonaceous nanofibers: batch experiments and modeling study

Carbonaceous nanofibers (CNFs) were synthesized by a hydrothermal carbonization method and characterized by microstructure characterization methods (SEM, TEM, XPS, FTIR) and potentiometric titration. The effect of the environmental facts on the adsorption of Eu(III) on CNFs were examined by the batch experiments. The maximum adsorption capacity of Eu(III) on CNFs was calculated to be 62.6 mg ∙ g^− 1 at pH 4.5 and 288 K. The thermodynamic parameters from Eu(III) adsorption isotherms at three temperatures suggested that this adsorption process was both spontaneous and endothermic. The CNFs/Eu(III) interactions were investigated by using diffuse layer modeling. The combination of a predominated [Formula presented])⁺ complex at pH < 3.5 and [Formula presented])⁺ and [Formula presented])₂ complex at pH > 3.5 was consistent with the experiment data. CNFs can be regarded as a promising environmental functional nanomaterial for the removal of lanthanides from radionuclide contaminated water.