Study of the Influence of Humic Acid on the Am(III) Sorption onto Kaolinite

In order to determine the influence of humic acid (HA) on the sorption of Am(III) onto kaolinite batch experiments were performed ([Am(III)] = 1x10-6 M, [HA] = 0 or 10 mg/L, I = 0.01 M NaClO4, pH = 3-10, solid/solution ratio = 1 or 4 g/L, pCO2 = 10-3.5 atm). In addition to that, laser-induced fluorescence spectroscopy was applied to study Am(III) kaolinite surface complexes in absence and presence of HA. The obtained results show that the presence of humic acid can affect the Am(III) migration under environmentally relevant conditions.