Effect of pyrolysis conditions on chemical properties of carbonized rice husks for efficient NH4+ adsorption

Applied Biological Chemistry

Table 2 Kinetic parameters of NH₄⁺ sorption on the carbides for Pseudo-second-order model

Carbonized rice husk	Type	K₂	h	q_e	R²
Carbonized rice husk	Type	(g/mg ∙ min)	h	(mg/g)	R²
pH 6.1	Type 1	26.004	0.183	11.933	0.997
pH 7.1		36.045	0.178	14.245	0.988
pH 11.0		26.541	0.373	8.432	0.999
pH 6.1	Type 2	24.862	0.189	11.481	0.962
pH 7.1		39.656	0.126	17.762	0.985
pH 11.0		19.430	0.214	9.533	0.953
pH 6.1	Type 3	0.001	0.015	11.927	0.908
pH 7.1		0.001	0.009	15.716	0.784
pH 11.0		0.003	0.028	9.021	0.845
pH 6.1	Type 4	0.001	0.169	12.365	0.908
pH 7.1		0.000	0.128	17.548	0.784
pH 11.0		0.003	0.222	9.415	0.845
pH 6.1	Type 5	0.004	0.864	15.083	0.975
pH 7.1		0.002	0.155	9.033	0.993
pH 11.0		0.002	0.009	1.992	0.743

K₂ constant of pseudo-second-order model, h initial adsorption rate of carbide, q_e, total amount of NH₄⁺ adsorbed by the biochar, R², coefficient of determination