Table 1: Adsorption rate constants of Ag+ and Cu++ adsorption onto clay derived from the pseudo-first-order and pseudo-second-order kinetic models.

Pseudo-first-orderPseudo-second-order
qe(mg/g)k1 (min−1)R2qe (mg/g)k2 (g/mg·min)R2

Ag+0.3770.9140.19719.703.671
Cu++0.2001.6000.00210.680.1191