Selective Adsorption of Uranium (VI) by Calix[6]arene-Modified Magnetic Graphene Oxide.

Magnetic graphene oxide/calix[6]arene (MGO-C6) composites were prepared and then characterized by Fourier transform infrared spectroscopy, Scanning electron microscope, X-ray diffraction and Thermo gravimetric analyzer, the adsorption of U(VI) by MGO-C6 from aqueous solution was investigated as a function of pH, contact time, initial U(VI) concentration and adsorbent dosage. The maximum adsorption rate of MGO-C6 can reach up to 93.21%, which was highly efficient for the removal of U(VI) under the condition of 1 mg/L initial uranium concentration. In addition, the selective adsorption experiment showed that MGO-C6 had an overall preference for U(VI). Adsorption process of MGO-C6 fitted well with the pseudo-second-order kinetic kinetics and the Langmuir isotherm model. The thermodynamic parameters illustrated that the adsorption process was endothermic and spontaneous. This work demonstrated that MGO-C6 was a promising adsorbent for removal of U(VI) from low concentration uranium-containing wastewater.