Investigation of some kinetic parameters for M2(+)-H+ exchanges on zirconium(IV) tungstophosphate - A cation exchanger

The kinetics and mechanism for the ion-exchange processes Mg2+-H+, Ca2+-H+, Sr2+-H+, Ba2+-H+, Zn2+-H+ Cd2+-H+, and Pb2+-H+ at 25 degrees C, 33 degrees C, 45 degrees C, 65 degrees C (+/-1 degrees C) temperatures on zirconium(IV) tungstophosphate were studied using approximated Nernst-Planck equation under the particle diffusion controlled phenomenon. Some physical parameters, i.e. fractional attainment of equilibrium U-(tau), self diffusion coefficients (D-0), energy of activation (E(a)) and entropy of activation (Delta S*) have been estimated. These investigations reveal that the equilibrium is attained faster at higher temperature probably due to availability of thermally enlarged matrix of zirconium(IV) tungstophosphate cation exchanger.