Researchers at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) have developed an innovative method of pre-enriching uranium in seawater by membrane filtration based on considerable differences in the diameter of hydrated ions between UO22 + and the main coexisting ions.
Researchers fabricated a new type of glycine cross-linked composite graphene oxide (GO-Gly) membrane with good ion-sieving properties, which can meet the demands of uranium pre-enrichment in seawater. The cross-linking of GO by glycine not only overcomes the swelling defect of GO membrane in solution, but also fulfills the requirement for the channel size of uranium separation from the main coexisting ions. Moreover, the structure of the membrane can keep stable when immersed in water solution for a long time.
The researchers investigated the ion rejection and enrichment properties of uranium and the main coexisting ions in single ion solutions and simulated seawater, respectively. They found that almost 100% of uranium was rejected by the GO-Gly membrane. In addition, only uranium was obviously enriched while the concentrations of the main coexisting ions kept nearly constant in continuously filtrating the simulated seawater with the membrane.
The results confirmed that the GO-Gly membrane is a good candidate for uranium pre-enrichment in seawater. This new method combined with the traditional methods is expected to improve the uranium recovery efficiency greatly and promote the real application of uranium resources in seawater.
According to World Nuclear News