Functionalized Polyethyleneimine Adsorbent for Efficient and Selective Uranium Extraction from Aqueous Solution

The sustainable treatment of uranium-containing wastewater is of significant importance for environmental protection. This study reports a novel Polyethyleneimine-4-cyanobenzaldehyde/p-Phthalaldehyde-Amidoxime (PEI-PAC-AO) adsorbent for the effective extraction of uranium from aqueous solutions. The structural and performance characteristics of the adsorbents were analyzed through FT-IR, TGA, SEM, CA, and ICP-MS. Adsorption mechanisms were investigated using X-ray photoelectron spectroscopy (XPS), revealing that uranium adsorption is due to coordination with N and O atoms in the amidoxime groups. Batch adsorption experiments showed that PEI-PAC-AO exhibited excellent removal efficiency at pH 6. The static adsorption performance better fits the Langmuir model and pseudo-second-order kinetics. Adsorption results indicated that the removal extent of uranium ions remained at 80% after nine consecutive adsorption cycles using 0.5 M nitric acid as the eluent. These findings suggest that PEI-PAC-AO is a sustainable and promising material for the efficient removal of uranium from wastewater, offering a sustainable and environmentally friendly approach that contributes to environmentally responsible wastewater treatment strategies.