On the sorption of anions by ferric oxide gel 1. Aqueous medium

Abstract

Sorption studies of SO 2− 4, Cl −, Br − and N0 − 3 ions on ferric oxide gel have shown that these ions replace surface OH groups. The particle diffusion-controlled exchanges follow mainly the Helfferich first mechanism. This situation is different from that in weak-base resins in the similar case of ionization of weakly dissociated groups by reaction with H + co-ions. The interdiffusion coefficient D i decreases in the order SO 2− 4 S> Cl − > Br − > NO − 3. It was deduced that, at least for SO 2− 4, the complexing ability with FE(III) at the gel/water interface is weaker than that in solution.