Aminopropyl Functionalised MCM-41: Synthesis and Application for Adsorption of Pb(II) and Cd(II)

Table 4

Regression parameters of the different nonlinear isotherm models for the adsorption of Pb(II) and Cd(II) on aminopropyl-MCM-41.

Ion	Isotherm (nonlinear form)	qm (mg·g^−1)	KL, KF, KR, or KS2	aR or aS	n, bR, or bS	RMSR
Pb(II)	Langmuir	64.00	4.59	—	—	0.877
	Freundlich	—	59.82	—	61.28	0.924
	Redlich–Peterson	—	322.15	5.06	0.99	0.876
	Sips	—	499.98	7.71	0.52	0.876
Cd(II)	Langmuir	14.17	0.21	—	—	0.440
	Freundlich	—	7.71	—	7.68	0.490
	Redlich–Peterson	—	3.37	0.25	0.98	0.440
	Sips	—	3.94	0.27	0.88	0.439