Removal of uranium(VI) ions from aqueous solution by magnetic cobalt ferrite/multiwalled carbon nanotubes composites

Cobalt ferrite/multiwalled carbon nanotubes (CoFe2O4/MWCNTs) magnetic hybrids were synthesized by a hydrothermal method. The as-prepared CoFe2O4/MWCNTs were then assessed as the adsorbent for uranium(VI) ions removal from water, and could be easily separated by an external magnetic field. Influencing factors to adsorb uranium(VI) ions were investigated, including pH, equilibrium time and temperature on uranium adsorption efficiency. The results indicated that uranium(VI) ions adsorption was strongly dependent on pH. The maximum adsorption capacity for uranium(VI) ions was calculated to be 212.7 mg Ulg based on the Langmuir model, displaying a high efficiency for the removal of uranium(VI) ions. Thermodynamic parameters further showed that the adsorption is an endothermic and spontaneous process. The CoFe2O4/MWCNTs showed their potential applications as adsorbent for highly efficient removal of heavy metal ions from aqueous solution. (C) 2015 Elsevier B.V. All rights reserved.