Yin Xueqiong, a professor of Hainan University's School of Engineering and Technology, had her research on a new-type uranium adsorbent published in the Chemical Engineering Journal.

Her research team prepared a sodium alginate (ALG)-based UO22+-imprinted thermoresponsive hydrogel (SUIT) with NIPAM as the starting monomer, and another hydrogel (SPUIT) with ɛ-polylysine (ɛ-PL) as a co-matrix to improve UO22+ adsorption capacity and stability. The maximum adsorption capacity of SUIT and SPUIT to UO22+ was 137.43 mg/g and 205.99 mg/g, respectively.

The desorption efficiency of SUIT and SPUIT was 96.46 percent and 97.21 percent, respectively, after washing the adsorbents with cold water, and decreased slightly to 82.42 percent and 84.99 percent after 10 cycles of the adsorption-desorption procedure. In the presence of other metal ions, the selectivity coefficients of SUIT and SPUIT for UO22+/Mn+ were in the range of 9.1-15.8 and 7.4-13.3. When tested with 20 liters of sea water, the adsorption capacity was 58.24 µg/g for SUIT and 59.69 µg/g for SPUIT, demonstrating a high potential of uranium accumulation. The introduction of ɛ-PL enhanced the antibacterial activity and resistance to the degradation of the hydrogel.

Uranium is a key raw material for producing nuclear fission energy. There are about 4.5 billion tons of uranium in seawater. Extracting uranium from seawater is expected to be an effective way to solve the shortage of uranium resources.