Removal of heavy metal ions by adsorptive particulate flotation

The removal of Zn, Cu and Ni ions, from diluted solutions, by the adsorptive particulate flotation (APF) process, was studied at laboratory scale. Zeolite (Chabazite) fines, in small concentrations, were used as the particulate sorbing for the metal ions and dissolved air flotation was employed for the solid/liquid separation of the loaded “carrier”. Results showed almost complete removal (>98 %) of the heavy metal ions using Fe(OH)3 precipitates to “aggregate” the carrier (coprecipitation). The process efficiency depended on solution and interfacial chemistry and aggregation effectiveness. The potential of APF in the field of effluent treatment is discussed.