Fig. 1 Protons and hydroxyls consumption (application minus addition in solution) by Ca–montmorillonite (CaMT) and K–montmorillonite (KMT) and Ca–kaolinite (CaKL) and K–kaolinite (KKL) (1:40 clay/electrolyte [0.01 M Cl^-] suspensions) as a function of suspension pH