Optimized Removal of Hydroquinone and Resorcinol by Activated Carbon Based on Shea Residue (Vitellaria paradoxa): Thermodynamics, Adsorption Mechanism, Nonlinear Kinetics, and Isotherms

Table 9

Adsorption of hydroquinone and resorcinol: nonlinear fitting analysis for two-parameter isotherms (see equations in Tables 3 and 4).

Models	Parameters		R^2	χ^2	Errors
					RMSE	HYBRID	ARE	EABS
HQ/CAK-S
Langmuir	Qm (mg/g)	45.764	0.992	0.336	4.363	5.603	0.014	0.385
	KL (L/min)	4.424
Freundlich	KF (mg/L)	30.482	0.997	0.096	2.335	1.605	0.162	0.005
	n	8.930
Temken	AT (L/mg)	1430.831	0.998	0.074	2.054	1.243	0.0006	2.52 × 10^−6
	ΔQ (J/mol)	587.068
Dubinin-Radushkevich	Qm (mg/g)	41.783	0.957	1.522	9.283	25.368	5.443	0.200
	Kid (L/mg)	5.12 × 10^−7
	E (kJ/mol) = 988.21
R/CAK-S
Langmuir	Qm (mg/g)	43.097	0.994	0.222	3.371	3.695	0.040	0.986
	KL (L/min)	1.212
Freundlich	KF (mg/L)	25.795	0.997	0.116	2.436	1.929	0.283	0.011
	n	7.524
Temken	AT (L/mg)	166.865	0.998	0.064	1.818	1.074	0.0001	7.35 × 10^−6
	ΔQ (J/mol)	514.132
Dubinin-Radushkevich	Qm (mg/g)	41.783	0.964	1.522	8.835	25.372	18.758	0.762
	Kid (L/mg)	5.26 × 10^−7
	E (kJ/mol) = 974.97