Adsorption of microamounts of ruthenium on hydrous iron oxides

The adsorption of Ru on amorphous Fe(OH)₃, -Fe₂O₃ and Fe₃O₄ have been measured as a function of the pH and the time of aging. The adsoprtion of Ru increases markedly in the 3–5.5 pH range. At higher pH values, -Fe₂O₃ shows different behaviour with respect to Ru adsorption. The influence of EDTA, citrate and oxalate on the adsorption of Ru on Fe₃O₄ has also been investigated. Possible mechanisms of the adsorption of Ru on hydrous iron oxides are discussed in the light of the results obtained in the course of this study and of those of other researchers.