Table 3.

Comparison of estimated parameters obtained from the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms for Cu(II) on NaP1 and NaP1CS.

Isotherm	Parameters	293 (K)	313 (K)	333 (K)
NaP1
Langmuir	KL (L/mg)	0.456	0.283	0.145
	RL	0.263	0.365	0.528
	qe (mg/g)	62.45	62.17	64.19
	R2	0.984	0.973	0.886
Freundlich	n	2.027	1.652	1.153
	KF (mg/g(L/mg)1/n)	15.04	12.48	9.79
	R2	0.808	0.796	0.881
Temkin	A (L/g)	20.89	0.47	4.49
	B (J/mol)	8.53	8.58	11.66
	R2	0.931	0.937	0.945
Dubinin-Radushkievich	Xm (mg/g)	239.1	131.2	43.2
	E (kJ/mol)	11.7	10.3	8.7
	R2	0.828	0.830	0.900
NaP1CS
Langmuir	KL (L/mg)	0.160	0.152	0.166
	RL	0.504	0.516	0.495
	qe (mg/g)	35.35	37.76	37.60
	R2	0.976	0.974	0.988
Freundlich	n	3.103	2.703	2.293
	KF (mg/g(L/mg)1/n)	7.59	7.01	6.56
	R2	0.871	0.793	0.734
Temkin	kT (L/g)	38.42	15.03	9.92
	B (J/mol)	3.52	4.44	4.84
	R2	0.949	0.929	0.919
Dubinin-Radushkievich	Xm (mg/g)	1043.3	766.5	540.2
	E (kJ/mol)	13.9	12.6	11.5
	R2	0.893	0.827	0.779