Table 2.

Adsorption kinetic parameters of CPX onto F_Zn (adsorbent doses: 1.6 g L⁻¹, pH: 5 to 6; contact time: 60 min).

Initial Concentration
	10 mg L−1	15 mg L−1	20 mg L−1	25 mg L−1	35 mg L−1	50 mg L−1	70 mg L−1
Experimental qe (mg g−1)	5.64	8.51	11.86	14.76	18.36	26.50	37.68
Pseudo-First Order
qe (mg g−1)	------	0.59	1.12	1.68	4.68	6.18	3.39
k1 (min−1)	------	0.03	0.04	0.04	0.07	0.07	0.04
Δqe (%)	------	93	91	89	74	77	91
R 2	------	0.969	0.999	0.990	0.989	0.928	0.889
Pseudo-Second Order
qe (mg g−1)	5.68	8.56	12.0	14.8	18.9	27.3	38.17
k2 (min−1)	0.19	0.15	0.09	0.07	0.03	0.02	0.28
Δqe (%)	0.59	0.54	1.56	0.24	2.8	2.8	1.28
R 2	0.999	1	1	0.999	1	0.999	0.999
Intraparticle Diffusion Model
kd 1	0.146	0.146	0.164	0.224	1.073	1.351	0.7947
C 1	4.756	7.537	10.68	12.94	12.56	18.52	32.45
R 2	0.981	0.979	0.999	0.942	0.988	0.931	0.9751
kd 2	0.022	0.033	−0.008	0.055	0.297	0.428	0.455
C 2	5.39	8.160	11.945	14.163	16.077	23.234	34.18
R 2	0.831	0.980	0.7913	0.999	0.9812	0.9583	0.993