Preparation of a Phosphorus-Containing Chelating Resin and Its Selectivity for Ionic Adsorption -Studies on Diphenyl Phosphonate-Formaldehyde Ion Exchange Resin IV-

Abstract

A chelating resin was prepared by the reaction of a diphenyl phosphonate-formaldehyde resin with trietylenetetramine for 4 h about 100°C. The adsorption capacity of the resin, for divalent metal ions was 1.8 Cu²⁺ mmol/g-R (dry resin) and for trivalent metal ions 0.80 Cr³⁺ mmol/g-R. Elution curves for Ca²⁺, Mg²⁺, Cu²⁺, Cd²⁺, Zn²⁺, Co²⁺, Ni²⁺ and Pb²⁺ were recorded by using 0.02 mol/l citric acid and 0.0 5 mol/l HCl. The separation, of metal ions. from each other and the recovery of Ca²⁺ and Mg²⁺ from large amounts of other, divalent metal ions are facilitated. The resin also showed goosl adsorption of. Cr(III) from buffer solutions of pH 5.0-7.0 and of Cr₂O₇^2- from buffer solutions of pH 2.0-7.0.