Humin is separated from a soil sample and characterized by elemental analysis, IR and potentiometric titration. These investigations
indicated that humin displayed similar characteristics as humic acid. The sorption behavior of137Cs,90Sr and153Gd with humin was investigated from aqueous solution. The results indicated that the sorption process follows the order: Gd3+≫Sr2+>Cs+. It was time dependent and increased with pH. The sorption in the presence of humic acid or EDTA showed that both form a
metal-ligand complex and consequently decrease the % uptake.