A simple and universal strategy to construct robust and anti-biofouling amidoxime aerogels for enhanced uranium extraction from seawater

Abstract For the uranium extraction from seawater in marine environments, the adsorbents need to possess sufficient mechanical strength to withstand the crashing force of the ocean waves, as well as anti-biofouling ability to prevent the blockage of the chelating sites by marine microorganisms. Herein, a facile one-step process is designed to massively construct robust and anti-biofouling poly(amidoxime) aerogels (Anti-PAO gels) for highly efficient uranium extraction. The gels display porosity, large surface area, flexibility, excellent mechanical strength to withstand the crash of the waves benefitting from the adhesive antibacterial compounds and the tight covalent bonding between the antibacterial compounds and PAO molecules, and the adsorption capacity reaches up to 1013 ± 9.7 mg-U/g-Ads in the 8 ppm uranium spiked solution. Significant inhibition zones are observed around the Anti-PAO gels, the adsorption amounts in bacteria-contained seawater reach 90.67%-94.82% of that in sterilized seawater, indicating the beneficial antifouling effects of the prepared aerogels for uranium extraction, providing an excellent extraction capacity of 9.29 ± 0.59 mg-U/g-Ads after a 30-day field test in natural seawater. More importantly, this developed strategy possesses universal applicability, and it can be used in other amidoxime molecules and other forms of uranium adsorbents to prepare the antifouling aerogels and fibers. Together with the economic analysis results, we believe that the developed amidoxime aerogels are promising in the industrialized uranium extraction from seawater.