Removal of Methylene Blue from Aqueous Solution Using Agricultural Residue Walnut Shell: Equilibrium, Kinetic, and Thermodynamic Studies

Table 3

Kinetic parameters for MB adsorption on WS.

/mg/L	, exp/mg/g	Pseudo-first order equation			Pseudo-second order equation			Intraparticle diffusion model
			, cal/mg/g	/g/mg·min		, cal/mg/g	k2/g/mg⋅min		C/mg/g	k3/mg/g⋅min^1/2
20	15.70	0.697	0.310	0.0290	1.000	15.72	0.097	0.778	14.91	0.074
40	28.88	0.748	2.494	0.0223	0.998	28.99	0.025	0.843	25.67	0.307
60	40.52	0.011	0.865	0.0039	1.000	40.49	0.102	0.336	39.46	0.097
80	48.22	0.567	5.733	0.0316	0.998	48.31	0.013	0.191	45.22	0.196
100	48.77	0.676	3.645	0.0129	1.000	48.08	0.020	0.710	43.32	0.471