Table 3.

Isotherm models parameters for toluene and p-xylene adsorption.

Model	Parameters	Toluene		p-xylene
		Pure CNTs	CNTs-iron oxide	Pure CNTs	CNTs-iron oxide
Langmuir	K L (L/mg)	0.005	0.002	0.008	0.003
	q m (mg/g)	127.94	381.18	219.51	458.52
	R 2 (%)	98.5	97.6	99.7	99.4
Freundlich	K F  (mg/g)/(mg/L)n	0.71	0.79	3.18	1.93
	n	1.08	0.99	1.32	1.11
	R 2 (%)	98.3	97.6	99.5	99.3
Dubinin-Radushkevich (D-R)	q m (mg/g)	24.62	39.11	76.32	100.58
	B (mole2/kJ2)	72.87	99.73	99.81	349.98
	E a (kJ/mole)	0.08	0.07	0.07	0.04
	R 2 (%)	99.2	99.2	99	98.4