TOXIC METALS REMOVAL FROM DILUTE-SOLUTIONS BY BIOSORPTIVE FLOTATION

Toxic metal ions (cadmium, nickel and zinc), considered as priority po llutants, were removed from dilute aqueous solutions by sorption onto non-living (sterilized) anaerobically digested sewage sludge. The deso rption of cadmium from metal-laden sludge was also examined. Flotation was subsequently applied as an effective solid/liquid separation proc ess. The dissolved-air flotation technique was applied for the generat ion of fine bubbles and, in parallel, electrokinetic measurements were carried out. Promising results were succeeded from the combined proce ss of biosorption/flotation (termed biosorptive flotation).