Table 1.

Models for adsorption isotherms.

Model	Equations	Parameters
Sips	(7)	Nads (mmol g−1) is the adsorbed amount, Nm (mmol g−1) is the adsorption capacity at equilibrium, P (kPa) is the equilibrium pressure, and KS and n are the Sips adsorption equilibrium constants, related to the affinity and the heterogeneity of the system, respectively.
Toth	(8)	Nads, Nm, and P have the same meaning as above, and KT and t are the Toth adsorption equilibrium constants, related to the affinity and the heterogeneity of the system, respectively.