Adsorption and Separation of Ca²⁺, Ba²⁺, and Sr²⁺ by using Diphenyl Phosphonate-Formaldehyde Chelate resin with Iminodiacetic Acid

Abstract

The titled chelate resin showed a good adsorption ability for Ca²⁺, Ba²⁺ and Sr²⁺ in the pH 8.0-10.0. The adsorption capacity of the titled chelating resin for Ba²⁺ was about 1.6 mmol/g-R on a dry resin. The rate of adsorption was high and adsorption equilibrium was attained with in 15 minutes. Ba²⁺ and Ca²⁺ or Ba²⁺ and Sr²⁺ loaded on the resin can be separated from each other by the elution with 1.0 mol⋅ dm^-3 CH₃COONH₄-20 vol% acetone solution, followed with 1.0 mol dm^-3 HCl.