Kinetics, Isotherm, Thermodynamics, and Recyclability of Exfoliated Graphene-Decorated MnFe₂O₄ Nanocomposite Towards Congo Red Dye

Table 2

Kinetic parameters of the CR adsorption models over MnFe₂O₄.

Kinetic models	Parameters	Concentration (mg/L)
		20	30	40	50	60
Pseudo-first-order	k1 (min^−1/(mg/L)^1/n)	0.013	0.010	0.014	0.016	0.009
	Q1 (mg/g)	5.12	8.67	7.13	17.31	7.42
	R^2	0.9187	0.6957	0.9672	0.7726	0.8762
Pseudo-second-order	k2 (g/(mg·min))	0.238	0.07	0.03	0.019	0.035
	Q2 (mg/g)	6.34	9.63	10.00	18.19	10.57
	H = k2Q2^2	9.57	6.52	2.94	6.14	3.92
	R^2	0.9663	0.8234	0.9882	0.8312	0.9706
Elovich	β (g/mg)	0.82	0.58	0.57	0.32	0.48
	α (mg/(g·min))	2.9	4.9	1.2	0.50	0.67
	R^2	0.9592	0.8007	0.9616	0.8472	0.9558
Bangham	kB 10^4 (mL/(g/L))	6.82	1.17	1.96	5.01	6.39
	αB	0.559	0.434	0.327	0.590	0.475
	R^2	0.9439	0.9272	0.9901	0.9803	0.9333