Facile Synthesis of Hollow MgO Spheres and Their Fluoride Adsorption Properties

Table 2

Langmuir and Freundlich adsorption isotherm parameters for fluoride on the hollow MgO spheres.

Equations	Langmuir model			Freundlich model
	Parameter	qm (mg/g)	kL (L/mg)	R^2	kF (mg/g)	nF	R^2
Values	200	0.030	0.962	162.9	2.73	0.996

Note: C_e is the equilibrium concentration of fluoride (mg/L); q_e is the amount of fluoride adsorbed on per weight of adsorbent after equilibrium (mg/g); q_m represents the maximum adsorption capacity of fluoride on per weight of adsorbent (mg/g); k_L is the Langmuir constant related to the energy of adsorption (L/mg); q_m and k_L were calculated from the slope and intercept of the linear plots of C_e/q_e vs C_e. The Freundlich constant k is correlated to the relative adsorption capacity of the adsorbent (mg/g), and 1/n is the adsorption intensity.