Effect of centrifugal force on electrodeposition of Hg2+ and Pb2+ at a spinning graphite cathode

An innovative technique has been developed in our laboratory permitting nea r total removal of toxic heavy metal ions like Hg2+ and Pb2+, in ppm concen tration, from wastewater by simultaneously employing the electrodeposition and the action of the centrifugal force. Matter having a density higher tha n pure water is concentrated at the bottom of the spinning container where a graphite cathode is located. Cu2+, being less toxic, was chosen as a mode l heavy metal ion to work out the detail of the dependency of removal of th e heavy metal ion on parameters like spinning velocity and spinning time of the centrifuge at a given optimal electrodeposition potential. It was dete rmined that Hg2+ (50.3 ppm) was removed near 100% at the spinning velocity of 6000 rpm in 20 min or less, for the same spinning velocity, Pb2+ (51.9 p pm) was removed 98.3% for a spinning time of 50 min. This high percentage o f removal of Hg2+ and Pb2+ from wastewater cannot be achieved by simple exh austive electrodeposition method alone. Our technique may have a significan t impact on industrial wastewater treatment processes dealing with the remo val of trace toxic heavy metal ions from the feed. (C) 2001 The Electrochem ical Society. All rights reserved.