KINETIC-ANALYSIS OF A BIMETALLIC ION-EXCHANGE SYSTEM BY MICROSCOPIC MEASUREMENT OF THE MOVING BOUNDARIES

Two different colored layers surrounding the central core have been ob served during the simultaneous uptake of copper and cobalt onto an imi nodiacetic-type ion exchange resin that was initially in the sodium fo rm. By measuring their width it is possible to calculate metal load on the basis of the local equilibrium assumption by using an equilibrium model for multimetallic systems. A kinetic pseudohomogeneous model ha s been developed which considers two successive mechanisms: first, dif fusion of metal ions through the reacted layer, and second, metal-meta l displacement from the solid phase. (C) 1994 Academic Press, Inc.