An Amidoxime-functionalized chitosan dual-network hydrogel: Enhanced uranium-water separation capacity

The source and after treatment of uranium, a key aspect of its use as a nuclear fuel, had been a topic of intense debate among developers. Therefore, a novel antimicrobial amidoxime-functionalized chitosan/polyacrylamide dual network hydrogel (CP-AO) had been developed utilizing a straightforward methodology. The results demonstrated excellent adsorption capacity and selectivity for uranium extraction under varying conditions, the U(VI) removal was above 94 % when pH was 4. Batch adsorption experiments revealed that CP-AO attained a maximum uranium adsorption capacity of 886.73 mg/g at 298 K, which was higher than most reported adsorbents. The kinetic and thermodynamic studies presented that adsorption process for CP-AO conformed to spontaneous monolayer chem-adsorption, and it can reach equilibrium quickly within 120 min. In addition, the adsorption mechanism revealed that the chemical-interaction between CP-AO hydrogel and U(VI) was attributed to -OH, -NH₂ and amidoxime group. Notably, the hydrogel showed optimistic anti-biosludge performance against three common bacteria (E. coli, S. aureus and B. subtilis) owing to effects of chitosan. CP-AO also especially was susceptible to be recycled, its adsorption capacity was 2.8 mg/g and 38.67 mg/g in simulated and actual seawater, respectively. Hence, this work provides a promising material for the extraction of uranium resources and new insights.