Separation of lead-212 from natural thorium solution utilizing novel sulfonamide dibenzo-18-crown-6

The extraction of lead-212 ( 212 Pb) from radioactive thorium (Th) waste is immensely important, as it serves to mitigate environmental risks associated with radioactive waste and provides a vital source for medical isotopes. To economically extract 212 Pb from thorium, we synthesized a novel extractant known as 2,13-disulfonyldiethylamine dibenzo-18-crown-6 (DSADB18C6). We assessed its performance in isolating Pb( ii ) by employing stable lead and optimizing the parameters of the extraction system. The results showcased an exceptional ability to extract Pb( ii ) efficiently. Within 10 minutes, using 20 mmol of DSADB18C6 and under conditions of 10 mg L −1 lead concentration (HNO 3 = 0.5 mol L −1 ), the extraction efficiency reached up to 96.1%. Even after four rounds of stripping with 0.4 mol L −1 ammonium citrate, the efficiency remained at 90.2%. Moreover, the extraction stoichiometry and thermodynamics revealed that DSADB18C6 exhibited superior extraction performance compared to the commercial extractant 4′,4′′,(5′′)-di-( tert -butyldicyclohexano)-18-crown-6 (DtBuDC18C6), in line with the density functional theory (DFT) calculation result. Furthermore, we successfully separated 212 Pb from the thorium nitrate solution, maintaining radioactive equilibrium with its progeny. Gamma-spectroscopy confirmed a recovery yield of extraction exceeding 85.7%. This study presents a viable approach, underscoring the potential of DSADB18C6 as a promising extractant for the effective separation of 212 Pb from radioactive thorium sources. The extraction of lead-212 ( 212 Pb) from radioactive thorium (Th) waste is immensely important, as it serves to mitigate environmental risks associated with radioactive waste and provides a vital source for medical isotopes.