Table 3.

The kinetic parameters for dye adsorption onto magnetic nanocomposites from binary solutions (nonlinear regression).

Sample	Fe3O4-SBA15	Fe3O4-SBA15-COOH-0.05	Fe3O4-SBA15-COOH-0.1
MB (MB + MG)
Qe exp (mg g−1)	174.48	193.16	201.84
Pseudo-first-order model
Qe cal (mg g−1)	168.43 ± 3.90	188.33 ± 2.79	196.20 ± 2.59
k1 (min−1)	0.0463 ± 0.0045	0.0747 ± 0.0049	0.1059 ± 0.0067
R2adjusted	0.9780	0.9884	0.9893
Pseudo-second-order model
Qe cal (mg g−1)	183.91 ± 1.53	200.34 ± 1.79	206.57 ± 1.64
k2 (10−4 g mg−1 min−1)	3.3498 ± 0.1546	5.5057 ± 0.3057	8.0765 ± 0.4467
R2adjusted	0.9980	0.9968	0.9969
MG (MB + MG)
Qe exp (mg g−1)	23.24	27.32	89.80
Pseudo-first-order model
Qe cal (mg g−1)	24.09 ± 0.50	27.20 ± 1.19	88.82 ± 2.18
k1 (min−1)	0.0111 ± 0.0072	0.0136 ± 0.0020	0.0178 ± 0.0016
R2adjusted	0.9951	0.9687	0.9878
Pseudo-second-order model
Qe cal (mg g−1)	30.62 ± 0.20	32.76 ± 1.58	105.70 ± 3.35
k2 (10−4 g mg−1 min−1)	3.5855 ± 0.0981	4.6580 ± 0.9505	1.8420 ± 0.2619
R2adjusted	0.9952	0.9821	0.9905