Table 3. Summary of Results for Experimental Data Fitting by the Intraparticle Diffusion Model to Explore the MB Dye Adsorption Mechanism onto the Superparamagnetic Nanocomposite Hydrogels at Different pH Media.

	AA-VSA-P/SPIONs-I			AA-VSA-P/SPIONs-II			AA-VSA-P/SPIONs-III
parameter	pH 9	pH 7	pH 1.4	pH 9	pH 7	pH 1.4	pH 9	pH 7	pH 1.4
k1d (mg/g min–0.5)	0.18	0.16	0.064	0.14	0.17	0.11	0.16	0.19	0
C1d (mg g–1)	0.03	0.3	0.002	0.07	0.04	0.01	0.04	0.008	0.09
R2	0.93	0.85	0.76	0.93	0.9	0.85	0.99	0.83	1
k2d (mg/g min–0.5)	0.08	0.05	0.04	0.07	0.06	0.03	0.06	0.06	0.03
C2d (mg g–1)	0.23	0.51	0.03	0.22	0.34	0.18	0.27	0.31	0
R2	0.98	0.99	0.99	0.99	0.97	0.98	0.99	0.99	0.97
k3d (mg/g min–0.5)	0.004	0.008	0	0.003	0.009	0	0.005	0.005	0
C3d (mg g–1)	1.67	1.41	1.16	1.65	1.27	0.93	1.5	1.44	0.74
R2	0.6	0.9	1	0.85	0.93	1	0.77	0.7	1