Kinetics constants for MB and RhB adsorption at different dye concentrations^a.

Pseudo-first-order kinetics					Pseudo-second-order kinetics				Intraparticle diffusion
Dye	q e,exp (mg g−1)	q e,cal (mg g−1)	k 1 (min−1)	R 1 2	k 2 (g mg−1 min−1)	q e,cal (mg g−1)	R 2 2	k p	I	R 3 2
MB
125	124.4	2.5	0.08	0.9631	0.058	125	1.00	13.7	31.1	0.7704
150	147.59	2.8	0.09	0.9575	0.021	151.5	0.9999	16.8	32.6	0.819
175	170.08	3.4	0.1	0.9732	0.016	175.4	0.9998	19.3	38.9	0.8089
200	193.3	4.3	0.11	0.9852	0.017	200	0.9999	21.8	47.2	0.7869
RhB
50	47	1.7	0.08	0.9622	0.019	51.02	0.9994	5.4	12.6	0.7646
75	69	1.9	0.09	0.9542	0.012	76.33	0.9994	8.2	16.7	0.8018
85	77.5	2.4	0.10	0.9634	0.009	86.95	0.9992	9.2	18.2	0.8144
100	91	3.4	0.17	0.989	0.007	101.01	0.9989	10.4	23.1	0.7781

^a q _t and q_e (mg g⁻¹) are the concentrations of dye adsorbed at any time t and equilibrium time (min), respectively. k₁ (min⁻¹) and k₂ (g mg⁻¹ min⁻¹) are the rate constants of adsorption for the pseudo-first-order and the pseudo-second-order models respectively, and k_p (mg g⁻¹ min⁻¹) and I are the intraparticle dissemination rate constant and intercept for the first linear phase.