Adsorption performance for bromine ion using bromide ion–lanthanum nitrate modified chitosan imprinted polymer

Abstract

Based on molecular imprinting techniques, and taking lanthanum nitrate modified chitosan as the functional monomer, bromide ion as the imprinting template, glutaraldehyde as the cross-linker, an imprinted polymer of bromide ion–lanthanum nitrate modified chitosan was prepared using surface imprinting methods. The H₂O₂ oxidation–extraction photometric method was used for the determination of bromide ion concentrations, and the selective adsorption performances of the resulting imprinted polymer for bromide ion from aqueous potassium bromide solution and artificial seawater were investigated. The experiments showed that the adsorption equilibrium time was 30 min and the maximum adsorption capacity was 4.81 mg g⁻¹ for potassium bromide solution, while the adsorption rate of artificial seawater was 71.57% and the adsorption capacity was 2.505 mg g⁻¹, the imprinted polymer had good reusability and its SEM was researched. Further research indicated that Cl⁻ and F⁻ in seawater had a significant impact on the adsorption performance of the imprinted polymer, but SO₄²⁻ and HCO₃⁻ had less effect.