Hydroxide ions are released by the resin as anions are adsorbed from the liquid phase. The effect is elimination of acidity in the liquid and conversion of the resin to a salt form. Typically, the resin is restored to the OH? form with a 4% solution of NaOH.
The hydroxide form is also used in salt splitting applications.
resin ? N(CH3)3OH-+Na+ + Cl- ?
resin ? N(CH3)3Cl- + Na+ + OH-
Salt forms of a strong base anion exchangerare used to remove other anions for which the resin has greater selectivity.
2 resin ? N(CH3)3Cl- +2Na+SO42- ?
(resin ? N(CH3)3)2SO42- +2 Na+ +2Cl-