Facile carboxylation of natural eggshell membrane for highly selective uranium (VI) adsorption from radioactive...

With the commercial nuclear technology rising in society nowadays, it is of paramount importance to remove uranium (VI) in radioactive wastewater through a cost-effective and efficient way. Due to simple operation, low cost and abundant adsorbents, the adsorption method has been widely used to treat the radioactive wastewater. However, unsatisfactory selectivity and potential secondary pollution of most adsorbents hamper their practical large-scale application. To overcome these limitations, an effective and green absorbent is developed by functionalizing the waste eggshell membrane (ESM) with carboxyl-rich agents. This design concept transfers waste ESM (or "trash") into a unique "treasure" absorbent for directly handling radioactive wastewater. The resultant ESM-COOH shows excellent adsorption selectivity toward uranium (VI) with the selectivity coefficient of 75%, exceeding a majority of reported adsorbents. Moreover, its adsorption capacity still maintains 84% of the initial value after six cycles, suggesting good reusability. These excellent features enable the ESM-COOH to adsorb uranium (VI) highly selectively and efficiently. This work offers a concept to transfer biological wastes into treasure for the mass remediation of water body.