Conjugating hyaluronic acid with porous biomass to construct anti-adhesive sponges for rapid uranium extraction from seawater

To withstand the complex natural environment and ecological system in the ocean, adsorbents with high strength, rapid rate, and antifouling ability are urgently needed for uranium extraction. Herein, instead of the traditional poly(amidoxime) structures, we design an anti-adhesive adsorbent (Anti-LS/SA) by conjugating functional ligands of salicylaldoxime (SA) and hyaluronic acid (HA) on the porous biomass via a facile one-step process. The interconnected microchannels in the porous biomass can accelerate seawater transport, along with the micromolecular uranium-adsorbing ligand, endowing the Anti-LS/SA with a very fast uranium adsorption ability; the average adsorption rates reach up to 131 ± 1.8 mg g−1 hour−1 (in uranium spiked seawater with concentration of 8 ppm) and 0.1176 mg g−1 day−1 (in natural seawater) in the main adsorption stages, exceeding the currently used oxime-based adsorbents. Owing to the high hydration of HA, the adsorbents exhibit excellent hydrophilicity and anti-bacterial adhesion properties, as demonstrated by the bacteria adhesion testing and extraction experiments in bacteria-spiked seawater. Furthermore, the Anti-LS/SA displays a long service life and a very high tensile strength (62.63 MPa) to withstand strong ocean waves. Kinetics models and XPS data are used to analyze the extraction mechanisms. Considering its high efficiencies, structural advantages, as well as the facile and massive construction, we believe that the Anti-LS/SA will be a promising candidate for the large-scale uranium extraction from seawater.