THE INFLUENCE OF ACTIVE CARBON OXIDATION ON THE PREFERENTIAL REMOVAL OF HEAVY METALS

Abstract

Oxidized active carbons were prepared by employing air- and acid-oxidation methods. Weakly acidic surface-functional groups were incorporated on the carbon surface. The distribution of functional groups varied with the oxidation techniques used. Metal sorption characteristics of oxidized active carbons were measured in both batch and minicolumn experiments. The materials preferentially adsorbed lead and copper over nickel and cadmium. Furthermore, a variable selectivity of oxidized carbons toward copper and lead was found to be based on the means by which the carbon was oxidized. Through alteration of oxidation treatment conditions and employment of different oxidizing agents, the selectivity behavior of the materials was controlled. Possible mechanisms of metal sorption are discussed.

ACKNOWLEDGMENTS

The authors would like to acknowledge the financial support of Brite-Euram Contract BRPR-CT96-0158 grant, Severn-Trent Water Ltd, and 2 ORS awards from the British Government.