Table 2.

Nonlinear Freundlich, Langmuir, Dubinin–Radushkevich, Temkin and Toth isotherm parameters for adsorption of metal ions onto Dowex 50WX8

Isotherm	Parameters	Metal ions
		DY(III)	Pr(III)	Y(III)
Langmuir	Qo (mg/g)	62.32	36.94	48.76
	b (ml/mg)	0.0041	0.0074	0.0035
	RL	0.707	0.575	0.739
	R2	0.956	0.995	0.978
	Chi^2	5.36	0.43	1.97
Freundlich	Kf (mg/g)	0.632	1.044	0.491
	1/n	0.719	0.569	0.694
	R2	0.944	0.971	0.959
	Chi^2	6.765	2.604	3.597
Dubinin–Radushkevich	qm	245.38	116.96	142.26
	β mol2 /kJ2	0.0078	0.0064	0.0086
	R2	0.952	0.484	0.971
	EDR	7.996	8.846	7.612
	Chi^2	2.20 E-10	7.11E-11	3.23E-10
Tempkin	$\mathrm{\Delta }Q$, kJ/mol	280.66	351.33	328.04
	K0, mmol/g	0.0888	0.1017	0.0657
	R2	0.8989	0.9738	0.9119
	Chi^2	12.3	2.34	7.77
Toth isotherm	qT, mg/g	23.19	25.02	49.11
	KT	0.035	0.04	0.017
	N	1.018	1.057	1.048
	R2	0.9668	0.987	0.991
	x2	1.504	1.19	1.688