An examination of the sorption characteristics of 241Am(III) and Eu(III) bound by humic substances chemically immobilized on silica gel

To facilitate investigations of the influence of humic substances on the migration of 241Am(III) in and around nuclear waste repositories we have chemically immobilized humic and fulvic acids on silica gels. It is anticipated that these materials might serve as geochemical models of the humate-coated minerals that are likely to be present in the vicinity of the repositories. The interaction of trivalent elements with humic substances have been investigated by a batch method use of the derivatized silica gels from perchlorate solutions at different pHs. By using these novel solid phases, complexing capacities and interaction constants are obtained at a constant ionic strength (0.1 M). The complexation of Am(III) is analyzed and compared with data in the literature. (orig.)