Capture chromatography for Mo-99 recovery from uranyl sulfate solutions: Minimum-column-volume design method

Molybdenum-99 (Mo-99), generated from the fission of Uranium-235 (U-235), is the radioactive parent of the most widely used medical isotope, technetium-99 m (Tc-99 m). An efficient, robust, low-pressure process is developed for recovering Mo-99 from uranyl sulfate solutions. The minimum column volume and the maximum column length for required yield, pressure limit, and loading time are determined using a new graphical method. The method is based on dimensionless groups and intrinsic adsorption and diffusion parameters, which are estimated using a small number of experiments and simulations. The design is tested with bench-scale experiments with titania columns. The results show a high capture yield and a high stripping yield (95 ± 5%). The design can be adapted to changes in design constraints or the variations in feed concentration, feed volume, or material properties. The graph shows clearly how the column utilization is affected by the required yield, loading time, and pressure limit. The cost effectiveness of various sorbent candidates can be evaluated based on the intrinsic parameters. This method can be used more generally for designing other capture chromatography processes.