Fast Recovery of Lead from Hydrochloric Acid via a Novel Silica-Supported Anion Exchange Resin for the Determination of 210Pb in Environmental Samples

The measurement of 210Pb is significant in environmental studies. Lead separation in HCl solution is a vital procedure but suffers from poor efficiency with high labor and time costs. To overcome this problem, a novel anion exchange resin was synthesized and characterized by different techniques followed by studies on the adsorption behaviors towards lead in HCl solution. The results suggest that SiPS-N(CH3)3Cl was successfully prepared with small particle size, low water swelling rate, and large specific surface area. The maximum anion exchange capacity resulted from quaternary amine groups was determined to be 1.0 mmol (Cl-)/g.The adsorption activities reached equilibrium within 3 min under selected conditions offering extremely fast adsorption kinetics. The synergistic adsorption mechanism, the multilayer adsorption mechanism, and the competition from co-existing chloride anions were found to be responsible for the lead adsorption performance of SiPS-N(CH3)3Cl. Column experiments showed that the feeding volume of lead and HCl had impact on the chemical yield regardless of the co-existence of high concentrations of FeCl3 (90 mM) and a high flow speed (4.0 mL/min). Based on these results, a separation process integrating SiPS-N(CH3)3Cl and the matched parameters was finally developed and tested. Our work greatly raised the lead separation efficiency in HCl solutions with implications for measuring 210Pb in environmental samples.