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

Table 3

Parameters of the isotherm equations determined by using the linear form of Pb(II) and Cd(II) adsorption on aminopropyl-MCM-41.

Ion	Isotherm (linear form)	qm (mg·g^−1)	KL, KF, KR, or KS2	aR or aS	n, bR, or bS	R^2
Pb(II)	Langmuir 1	66.66	5.00	—	—	0.574
	Langmuir 2	66.66	7.50	—	—	0.999
	Langmuir 3	63.99	4.67	—	—	0.552
	Langmuir 4	64.64	2.57	—	—	0.552
	Langmuir 5	64.56	2.64	—	—	0.574
	Freundlich	—	59.73	—	62.50	0.523
	Redlich–Peterson	—	341.86	5.39	0.99	0.999
	Sips	—	500.00	7.50	0.68	0.583
Cd(II)	Langmuir 1	14.28	0.21	—	—	0.888
	Langmuir 2	14.28	0.22	—	—	0.991
	Langmuir 3	14.13	0.22	—	—	0.815
	Langmuir 4	14.54	0.18	—	—	0.815
	Langmuir 5	14.40	0.19	—	—	0.888
	Freundlich	—	7.58	—	7.46	0.828
	Redlich–Peterson	—	2.96	0.20	1.00	0.996
	Sips	—	3.27	0.22	0.97	0.888