Removal of Methylene Blue from Aqueous Solution by Activated Carbon Prepared from Pea Shells (Pisum sativum)

Table 3

Pseudo-first-order and pseudo-second-order models for the adsorption on activated carbon prepared from pea shell.

Kinetic models and its parameters	Initial concentrations (mg/L)
	100	150	200	250	300	350
𝑞𝑒,exp (mg g^−1)	99.65	148.73	190.66	217.20	227.85	247.49
Pseudo-first-order kinetic
𝑞𝑒,cal (mg g^−1)	13.36	84.49	84.86	125.96	123.08	116.17
𝑘1  (min^−1)	0.049	0.043	0.024	0.025	0.022	0.022
𝑅^2	0.9638	0.9704	0.9958	0.9871	0.9889	0.9830
Pseudo-second-order kinetic
𝑞𝑒,cal  (mg g^−1)	100.40	154.32	201.21	232.02	245.10	264.55
𝑘2  (g mg^−1 min^−1)	0.00910	0.00110	0.00050	0.00030	0.00028	0.00029
ℎ (mg g^−1 min^−1)	91.41	26.92	19.30	18.17	16.79	20.68
𝑅^2	0.9999	0.9998	0.9999	0.9998	0.9995	0.9993