Amidoximated cellulose microspheres synthesized via homogenous reactions for High-Performance extraction of uranium from seawater

Highly efficient extraction of uranium from seawater is regarded as an important guarantee for the promotion of nuclear electricity generation. Amidoxime based adsorbents are considered as the most promising materials for uranium recovery due to their high selectivity and binding capability to uranyl ions. Herein, natural celluloses with advantages of low cost, biodegradability, renewability were chosen as the raw materials. Moreover, amidoximated cellulose-based adsorbents are fabricated by two steps of homogeneous reactions including the Michael addition and amidoximation reaction. Compared with traditional surface grafting methods, both the grafting density of active adsorption sites and the utilization of raw materials could be greatly improved because of the lower steric hindrance as well as more exposed reactive sites during the homogeneous reactions. The adsorption capacity of our adsorbents can reach as high as 517.07 mg/g at pH = 7, one of the best cellulose-based adsorbents as far as we know. In addition, excellent hydrophilicity of the adsorbents, which is inherited from the natural cellulose, can endow them with enhanced mass transfer as well as resistance to marine pollutants. More importantly, the adsorption microspheres would be filled into filtration column for dynamic adsorption benefited from their aforementioned merits. The average adsorption capacity could maintain above 2.5 mg/g per day when the filtration column was exposed to simulated seawater for 24 days. All these characteristics make the amidoximated cellulose-based adsorbents potentially applicable to the uranium recovery from seawater.