The effect of solution and column parameters such as pH, ratio of metal ions and the height of resin bed on formation of the thermo-induced concentration waves (TICW) in the course of the thermostripping process of Cu2+ and Zn2+ ions from iminodiacetic resin Lewatit TP-207 has been studied. The formation of TICW is attributed by both different diffusivities of metal ions and the presence of the third (H+) ion in the system. This effect makes it possible to carry out a reagentless separation of metal ions by using either the metal depletion or metal concentration mode of operation. The efficiency of the TICW-based separation process by using the metal depletion mode appears to be the higher the lower relative concentration of metal ion under removal (slower diffusing ionic species). The mathematical model proposed allows for qualitative and quantitative description of thermostripping processes in a wide range of pH and solution compositions. The physical model of the TICW process proposed makes it possible to account for the influence of different process parameters and generalise the applicability of the TICW separation technique to the binary mixtures of any metal ions with different diffusivities. Copyright (C) 2000 Elsevier Science B.V.
|Journal||Journal of Chromatography A|
|Publication status||Published - 21 Jan 2000|
- Concentration waves, thermo-induced