Experimental investigations on the removal of Cd(II) from aqueous solution were carried out through two foam separation techniques : ion flotation and adsorbing colloid flotation with Fe(III). The optimum pH for good removal was found to be about 6.4 for the former and about 11 for the latter. The effects of flotation time, pH, surfactant(sodium lauryl sulfate), foreign ions(Na⁺, Ca²⁺, NO₃^-, SO₄^2-) on the efficiency of Cd(II) removal were discussed. The presence of foreign ions inhibit the Cd(II) removal by foam flotation. It was suggested that the limitation of foam flotation on Cd(II) removal may be overcome by the surface activity of mixed surfactant solution. The application of the synergistic effect of mixed surfactant solutions to the improvement of the removal efficiency of foam flotation was experimentally verified in this work.