Adsorption of ions onto amorphous silica: ion exchange model.
Single site ion exchange model was applied for description of the published data on adsorption of sodium, calcium, cadmium, and zinc onto amorphous silica. The following equilibria were detected (25 degrees C; X-adsorption site; TotX=6 micromol/m2): 2X + Na+ OH* <=> XNa+ XOH*, log K degree = 5.1, 3X + Me2+ +2OH*<=> XMe2+ 2XOH*, log K degree = 11.6 (Ca), 11.7 (Cd), 2X + Me2+ + 2OH* <=> XMeOH+ + XOH*, log K degree = 14.1 (Cd), 15.5 (Zn).
Pivovarov
Sergey
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