Crosslinked polymer aerogel with multiple binding sites for efficient uranium separation from uranium-containing...

The toxicity of uranium necessitates its cost-effective and efficient removal from nuclear wastewater due to the associated environmental and health risks. Among various removal methods, solid-phase adsorption holds particular promise. However, its commercial adoption is currently hindered by the complicated synthesis, high cost, and unsatisfactory performance of existing uranium adsorbents. In this study, we developed a highly hydrophilic crosslinked polymer aerogel with abundant carbonyl and phosphate groups, prepared by a simple solvothermal method from readily available precursors and evaluated as a uranium adsorbent. The developed aerogel exhibited a high adsorption efficiency of 97.5 % within 190 min, a maximum theoretical uranium adsorption capacity of 426.1 mg/g, which is far superior to most phosphate-functionalized polymers, and robust salt tolerance with an 88.4 % uranium adsorption efficiency in the existence of 0.5 M NaNO₃. Moreover, it exhibited exceptional selectivity with a uranium adsorption efficiency of 96.5 % even in the presence of multiple interfering ions. This high performance is attributed to the strong binding of uranyl cations due to the synergistic effects of phosphate and carbonyl groups. These findings indicate the potential of our aerogel for removing uranium from wastewater, presenting a valuable addition to the library of polymeric uranium adsorbents.