Synthesis of carboxyl group functionalized silica composite resin for strontium removal

Radioactive strontium 90 Sr with a half-life of 29 years is one of the most concerned elements in both nuclear accidents and spent fuel reprocessing. Herein, using macroporous silica SiO 2 as support, methylacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linking agent, a novel resin named SiMaC was prepared via in situ polymerization method for strontium removal. The as-preapred SiMaC was characterized by SEM-EDS, TG-DSC, and BET. Various factors such as pH, m/V, time, and initial concentration of Sr(II) were studied. The maximum adsorption capacity towards Sr(II) was as high as 142.5 mg/g at 298 K. The adsorption equilibrium was almost obtained within 30 min. Moreover, SiMaC was easily and fastly regenerated by 0.1 M HCl and exhibited no obvious decrease in adsorption capacity after five times of successive adsorption-desorption cycles. Most attractively, the uptake rate of Sr(II) reached more than 99% in real river and lake water mediums, as well as reached 76% in real seawater mediums. Finally, XPS and FTIR were used to analyze the adsorption mechanism towards Sr(II).