Discussion on 'a mechanistic description of Ni and Zn sorption on Na-montmorillonite' (Part 1 and Part 2)

摘要

The quantitative description developed by Baeyens and Bradbury (1997) and Brad- bury and Baeyens (1997) of the sorption of Me(II) and H_+ on Na-montmorillonite, combining ion exchange binding on negative permanent negative charge sites with surface complex formation on the surface hydroxyl groups of "broken bond" sites, gives a powerful generalisation predicting the interaction of the clay with cations in dependence of solution variables; one readily appreciates the role played, above all, by pH and background electrolyte concentration (ionic strength) in determining under what conditions metal ion sorption is dominated by ion exchange or by surface complexation.