Table 2. Kinetics modeling parameters for CR and NR dyes.

Model		CR at pH = 2			NR at pH = 11
Pseudo-1st-order kinetics		R 2 = 0.73	Q c, calc. = 37.65	K 1 = 0.029	R 2 = 0.89	Q c, calc. = 61.74	K 1 = 0.024
Pseudo-2nd-order kinetics		R 2 = 0.99	Q c, calc. = 200	K 2 = 2.45 × 10−3	R 2 = 0.99	Q c, calc. = 175.43	K 2 = 1.44 × 10−3
Intraparticle diffusion model	1st stage	R 1 2 = 0.99	C 1 = 2.4 × 10−4	K id1 = 44.18	R 1 2 = 0.99	C 1 = 2.4 × 10−4	K id1 = 37.93
	2nd stage	R 2 2 = 0.005	C 2 = 198.09	K id2 = 0.02	R 2 2 = 0.70	C 2 = 149.36	K id2 = 1.54
Parameter (Unit): Qc, calc. (mg g−1); K1 (1/min); K2 (g mg−1 min−1); C1 and C2 (mg g−1); Kid (mg g−1 min1/2)