Table 4. Adsorption Kinetic Models of As(V), Cr(VI), and B(III) for Poly-VbMEG Loaded on Fe₃O₄ Fitted with the Pseudo-First-Order, the Pseudo-Second-Order, and the Intraparticle Diffusion Models.

	As(V)					Cr(VI)					B(III)
C0 (μg/L)	500	1150	2500	8500	16500	500	1150	2500	8500	16500	500	1150	2500	8500	16500
Qexp (mg/g)	0.3	0.6	1.2	3.9	7.6	0.3	0.6	1.2	4.1	7.5	0.2	0.5	1.1	2.7	5.3
Pseudo I-order
K1 (min–1)	4.6	4.1	2.4	2.0	2.4	6.2	6.3	4.8	4.1	4.1	4.4	3.0	3.1	3.5	4.4
R2	0.99	0.98	0.95	0.94	0.97	0.88	0.88	0.89	0.92	0.86	0.91	0.99	0.94	0.98	0.97
Qet (mg/g)	0.1	0.3	1.0	3.1	5.5	0.1	0.3	1.8	2.1	3.9	0.1	0.3	1.5	2.4	4.0
Pseudo II-order
K2 (min–1)	3.98	1.71	0.80	0.24	0.13	3.98	1.72	0.80	0.24	0.13	4.62	2.02	0.91	0.34	0.18
R2	0.99	0.97	0.98	0.99	0.99	0.99	0.99	0.99	0.99	0.99	0.99	0.98	0.99	0.99	0.99
Qet (mg/g)	0.3	0.6	1.2	4.2	7.9	0.3	0.6	1.2	4.1	7.6	0.2	0.5	1.1	2.9	5.5
Intraparticle Diffusion
Kip	0.002	0.01	0.03	0.09	0.16	0.003	0.01	0.02	0.07	0.14	0.004	0.01	0.02	0.07	0.13
R2	0.87	0.87	0.97	0.97	0.97	0.71	0.71	0.77	0.82	0.78	0.85	0.91	0.84	0.96	0.80