The present paper presents the influence of the ionic liquid nature impregnated onto Florisil upon the adsorption performance of the obtained material in the removal process of Tl(I) ions from aqueous solutions. The impregnation of the studied ionic liquid onto Florisil was realized through ultrasonication which proved to be an efficient method because is not time consuming, combine the advantages of the ionic liquids with those of the solid support, is used a smaller amount of the ionic liquid and there is no risk of loss of the extractant in the aqueous phase. The FTIR, SEM, and energy dispersive EDX applied to the obtained adsorbents proved the fact that the Florisil solid support was impregnated with the studied ionic liquids and also put in evidence the morphology changes of the solid support produced by its impregnation with these ionic liquids. Equilibrium, kinetic and thermodynamic data were applied in order to determine the efficiency of the studied adsorbent in the removal process of Tl(I) ions. The phosphonium based ionic liquid impregnated onto Florisil developed a higher efficiency in the removal process of thallium ions from aqueous solution then the materials obtained through impregnation of Florisil with imidazolium based ionic liquids. (C) 2015 Elsevier B.V. All rights reserved.