Efficient and selective extraction of uranium from seawater based on a novel pulsed liquid chromatography radionuclide separation method

The novel pulsed liquid chromatography radionuclide separation method presented here provides a new and promising strategy for the extraction of uranium from seawater. In this study, a new chromatographic separation method was proposed, and a pulsed nuclide automated separation device was developed, alongside a new chromatographic column. The length of this chromatographic column was 10 m, with an internal warp of 3 mm and a packing size of 1 mm, while the total separation units of the column reached 12,250. The most favorable conditions for the separation of nuclides were then obtained through optimizing the separation conditions of the device:Sample pH in the column=2, sample injection flow rate=5.698 mL/min, chromatographic column heating temperature=60℃. Separation experiments were also carried out for uranium,europium, and sodium ions in mixed solutions; uranium and sodium ions in water samples from the Ganjiang River; and uranium, sodium, and magnesium ions from seawater samples. The separation factors between the different nuclei were then calculated based on the experimental data, and a formula for the separation level was derived. The experimental results showed that the separation factor in the mixed solution of uranium and europium (1:1) was 1.088, while achieving the initial separation of uranium and europium theoretically required a 47-stage separation. Considering the separation factor of 1.50for the uranium and sodium ions in water samples from the Ganjiang River, achieving the initial separation of uranium and sodium ions would have theoretically required at least a 21-stage separation. Furthermore, for the seawater sample separation experiments, the separation factor of uranium and sodium ions was 1.2885; therefore, more than 28 stages of sample separation would be required to achieve uranium extraction from seawater. The novel pulsed liquid chromatography method proposed in this study was innovative in terms of uranium separation and enrichment, while expanding the possibilities of extracting uranium from seawater through chromatography.