Adsorption of calcium and magnesium ions on surfaces

The adsorption of calcium and magnesium ions at trace levels in solution on borosilicate glass and polypropylene is described. The rate and extent of adsorption increases with increasing pH and the process is not completely reversible. The apparent energies of activation for the adsorption of calcium and magnesium ions on borosilicate glass are 17.5 and 10.5 kJ mol^?1, respectively. The corresponding half-lives are 568 and 127 h. For polypropylene the half-lives increase to 5775 and 537 h, respectively.