Table 1. Theoretical Parameters for the Investigated Kinetic and Equilibrium models.

kinetic models
model	parameters	SF	MG	CR	MO
pseudo-first-order	K1 (min–1)	4.9 × 10–7	7.47 × 10–5	2.72 × 10–6	4.49 × 10–6
	qe(Cal) (mg/g)	202	217	251.7	294.3
	R2	0.98	0.98	0.99	0.99
	χ2	2.12	1.86	1.12	0.87
pseudo-second-order	k2 (g/(mg min))	2.49	1.95	2.26	2.09
	qe(Cal) (mg/g)	207	221.4	254.2	297
	R2	0.98	0.98	0.98	0.98
	χ2	2.7	2.54	1.45	1.22
Elovich	β (g/mg)	0.013	0.014	0.011	0.01
	α (mg/(g min))	3.23	4.49	4.2	4.72
	R2	0.88	0.86	0.89	0.91
	χ2	5.8	6.6	5.3	4.2

isotherm models
model	parameters	SF	MG	CR	MO
Langmuir	qmax (mg/g)	431.6	489.9	626.2	675.5
	b (L/mg)	3.7 × 10–6	4.07 × 10–5	1.02 × 10–4	9.3 × 10–4
	R2	0.99	0.98	0.98	0.90
	χ2	0.87	2.14	2.23	3.6
	RL	0.99–0.998	0.98–0.997	0.96–0.99	0.73–0.95
Freundlich	1/n	0.45	0.57	0.63	0.71
	kF (mg/g)	182	234.5	128.8	30.7
	R2	0.99	0.97	0.97	0.87
	χ2	2.3	4.7	4.36	5.7
D–R model	β (mol2/kJ2)	0.496	0.43	0.403	0.183
	qm (mg/g)	446	486.9	607.4	667.8
	R2	0.99	0.96	0.95	0.84
	χ2	4.6	6.23	6.8	7.3
	E (kJ/mol)	1.01	1.08	1.11	1.65