Table 3. Kinetic Parameters Obtained from the Pseudo-First-Order and Pseudo-Second-Order Fitting on the Adsorption Process of Pb²⁺ and Cd²⁺ over Fe–MOF and Co_x–Fe_1–x–MOFs.

		qe(Exp) (mg/g)	pseudo-first-order			pseudo-second-order
metal ions	sample		qe1 (mg/g)	K1	R2	qe2 (mg/g)	K2 × 10–4	R2
Pb2+	Fe–MOF	118.4	220.17	0.025	0.9526	121.6	7.36	0.9891
	Co0.25–Fe0.75–MOF	177.5	302.48	0.036	0.9883	176.2	9.44	0.9926
	Co0.50–Fe0.50–MOF	193.4	358.53	0.041	0.9714	201.3	17.79	0.9968
	Co0.75–Fe0.25–MOF	168.1	404.64	0.033	0.9132	162.2	12.29	0.9929
Cd2+	Fe–MOF	111.5	260.8	0.019	0.8382	123.1	3.6	0.9977
	Co0.25–Fe0.75–MOF	169.3	429.8	0.035	0.9659	187.2	83.6	0.9926
	Co0.50–Fe0.50–MOF	182.2	597.3	0.039	0.9713	195.3	92.9	0.9968
	Co0.75–Fe0.25–MOF	154.5	962.9	0.050	0.9715	172.1	1.6	0.9881