Improvement of the removal efficiency of Cd(II) from the aqueous solution by adsorbing colloid flotation

Experimental investigations on the removal of Cd(II) from aqueous solution were carried out through adsorbing colloid flotation with Fe(III). The optimum pH for good removal was found to be 11. The effects of flotation time, pH, surfactant (sodium lauryl sulfate) foreign ions (NaNO3, Na2SO4 and Ca(NO3)(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 solutions. The application of the synergistic effect of mixed surfactant solutions to the improvement of the removal efficiency of foam flotation was verified experimentally.