Kinetic model data of Cu(ii), Zn(ii), Cd(ii), and Pb(ii) adsorption.

Parameters	Metal ions
Experimental	Cu(ii)	Zn(ii)	Cd(ii)	Pb(ii)
q e(exp) (mg g−1)	90.25	75.38	55.23	35.12
Pseudo-first order
q e (mg g−1)	27.234	16.09	8.309	2.872
k 1 (g mg−1 min−1)	0.135	0.127	0.100	0.070
R 2	0.8891	0.9963	0.9481	0.6647
Pseudo-second order
q e (mg g−1)	92.592	77.519	56.497	35.714
k 2 (g mg−1 min−1)	0.013	0.016	0.023	0.050
R 2	0.9999	0.9999	0.9998	0.9965