Table 2.

Adsorption isotherm constants for phosphorus removal by alumina adsorbents.

Kinetic Model	Parameter	SB-500	GA-1-500	GA-2-500
Langmuir isotherm model $q_{\mathrm{e}}=\frac{q_m{K}_{\mathrm{L}}{C}_{\mathrm{e}}}{1+K_{\mathrm{F}}{C}_{\mathrm{e}}}$	qm,cal (mg·g−1)	276.5	588.2	360.1
	KL (L·mg−1)	0.0021	0.0468	0.0112
	R2	0.998	0.969	0.990
Freundlich isotherm model $q_{\mathrm{e}}=K_{\mathrm{F}}{c}_{\mathrm{e}}^{1/n}$	1/n	0.75	0.27	0.45
	KF ((mg·g−1)(L·mg−1)1/n)	2.71	124.88	23.51
	R2	0.992	0.981	0.980

where C_e (mg·L⁻¹) and q_e (mg·g⁻¹) are the concentration of adsorbate in aqueous solution in equilibrium state and the amount of adsorbed adsorbate at equilibrium, respectively; q_m (mg·g⁻¹) denotes the theoretical saturated monolayer adsorption capacity for the adsorbent calculated by the Langmuir isotherm model; K_L (L·mg⁻¹) represents the Langmuir constant; and K_F and 1/n are the characteristic constants of the Freundlich isotherm, which are the measurements of adsorption capacity and adsorption intensity, respectively.