Enhanced Adsorption of Orange II Using Cationic Surfactant Modified Biochar Pyrolyzed from Cornstalk

Table 1

Parameters for the nonlinear kinetic models including pseudo-first-order, pseudo-second-order, and Elovich models.

Kinetic model	pH = 3	pH = 5	pH = 7	pH = 9	pH = 11
Pseudo-first-order
k1 (min^−1)	0.117	0.159	0.191	0.139	0.235
(mg/g)	20.9	17.2	14.6	11.3	7.00
R^2	0.903	0.901	0.922	0.956	0.901
Pseudo-second-order
k2 (g/mg·min)	0.00866	0.0150	0.0221	0.0204	0.0569
(mg/g)	21.9	17.9	15.2	11.7	7.3
R^2	0.971	0.967	0.975	0.989	0.954
Elovich
a	10.34	9.997	9.325	6.360	4.679
k	2.099	1.234	0.992	0.878	0.450
R^2	0.981	0.992	0.996	0.968	0.998