Selective removal of U(VI) from low concentration wastewater by functionalized HKUST-1@H₃PW₁₂O₄₀

The adsorption of U(VI) from low concentration solution by HKUST-1@H₃PW₁₂O₄₀ was studied as a function of various experimental parameters including pH, interfering ions, contact time, initial uranium concentration and temperature by batch experiments. Equilibrium data were found to fit with Langmuir isotherm model better than Freundlich isotherm model. The kinetic adsorption was fitted by the pseudo-second-order model well. Thermodynamic data from the adsorption experiments indicate that adsorption process is spontaneous and endothermic. HKUST-1@H₃PW₁₂O₄₀ can selectively adsorb U(VI) from multi-metal ion solutions and the adsorption capacity of HKUST-1@H₃PW₁₂O₄₀ don't decrease significantly after three cycles of desorption-reuse. The results show that HKUST-1@H₃PW₁₂O₄₀ is suitable for removal of U(VI) from low concentration solutions. (author)