Adsorption kinetics of platinum group elements in river water.

The uptake of platinum group elements (PGE) by different preparations of estuarine sediment suspended in filtered river water has been examined. For a given PGE, adsorption time courses to untreated sediment and to sediment whose hydrous metal oxides or organic matter had been removed by appropriate chemical treatments were similar. Adsorption of Rh(lll) and Pt(IV) proceeded via a first-order reversible reaction.