Removal of Metal Pollutants (Cd(II) and Cr(III)) from Phosphoric Acid Solutions by Chelating Resins Containing Phosphonic or Diphosphonic Groups

In this study, chelating ion exchangers containing phosphonic (−PO(OH) 2 ) acid groups (RSPO, Diaion-CRP200) and the new chelating resins (Diphonix) containing sulfonic and gem -diphosphonic acid groups chemically bonded in a styrene−divinylbenzene polymeric network have been investigated for sorption of Cd(II) ions from phosphoric acid solutions. Comparison of acid dependencies of Cd(II) uptake measured with that obtained using a commercial sulfonic acid type ion-exchange resin (Dowex 50W(X8)) and a solvent containing resins (Actinide-CU) has been performed. The resin Diphonix has been employed for columnar sorption of Cd(II) and Cr(III) ions from phosphoric acid solutions.