Table 1.

Kinetic model parameters for the sorption of Cu²⁺, Zn²⁺, and Ni²⁺ ions onto sorbents.

Kinetic Modelsa	$\mathbf{PFO}:{\mathit{q}}_{\mathit{t}}={\mathit{q}}_{\mathit{e}}\left(1-\mathit{e}\mathit{x}{\mathit{p}}^{-{\mathit{k}}_1\mathit{t}}\right)$; k1—Rate Constant of the PFO Kinetic Model, min−1				$\mathbf{PSO}:{\mathit{q}}_{\mathit{t}}=\frac{{\mathit{q}}_{\mathit{e}}^2{\mathit{k}}_2\mathit{t}}{1+{\mathit{q}}_{\mathit{e}}{\mathit{k}}_2\mathit{t}}$; k2—Rate Constant of the PSO Kinetic Model, g mg–1 × min–1
Sorbents					Sorbents
Metal Ions		CPLH+	CGCS	CGCS_ CPLH+		CPLH+	CGCS	CGCS_ CPLH+
Cu2+	qe,calc	8.97	35.80	57.15	qe,calc	8.14	29.42	50.77
	k1	0.03	0.01	0.02	k2	0.005	0.0004	0.0005
	R2	0.99	0.96	0.97	R2	0.99	0.98	0.98
	χ2	0.08	5.79	8.71	χ2	0.08	2.36	5.49
Zn2+	qe,calc	0.36	2.84	5.46	qe,calc	0.32	2.27	4.73
	k1	0.02	0.01	0.02	k2	0.09	0.004	0.004
	R2	0.94	0.96	0.99	R2	0.98	0.98	0.99
	χ2	0.0008	0.04	0.03	χ2	0.0002	0.02	0.01
Ni2+	qe,calc	0.16	0.75	1.47	qe,calc	0.13	0.69	1.34
	k1	0.01	0.03	0.04	k2	0.08	0.07	0.03
	R2	0.94	0.91	0.98	R2	0.97	0.96	0.99
	χ2	0.0009	0.005	0.003	χ2	0.002	0.002	0.001

^aq_e,calc is the calculated amount of HMIs adsorbed on sorbents, mg·g⁻¹.