Fig. 4. Uranium(VI) adsorption to the bioreduced-reoxidized sediment with variable concentrations of Fe(II) addition. The sediment was oxidized after Fe(II) addition and before uranyl addition for sorption experiments. The total U(VI) concentration was 10 µmol/L. (a) U(VI) adsorption edges, (b) aqueous U(VI) concentration. The lines were generated from a ferrihydrite adsorption model (see text).