where, Ce, qe are the concentration of the dye in solution (mg L1) and the loading of the dye on the adsorbent (mg g1) at equilibrium, respectively, KL is a direct measure of intensity of the adsorption process (mL mg1), qm is the Langmuir maximum monolayer adsorption capacity (mg g1), KF (mg1n Ln g1) and n are the Freundlich isotherm constants. 1/n is a measure for the surface heterogeneity and 1/n values lesser than 1 indicate a higher adsorption intensity. From a linear fit to sorption isotherm data plotted on 1/qe vs. 1/Ce, qm and KL can be determined based on the slope and the intercept. Similarly, KF and 1/n can be determined from the intercept and slope of a linear fit to sorption data plotted on ln (qe) vs. ln (Ce) axes.