In this equation qe is adsorption capacity at equilibrium (mg/g), Ce
is the equilibrium solute concentration (mg/l), k and n are the
Freundlich constants. The higher value of k indicates higher
adsorption capacity and higher value of n indicates the stronger
adsorption bond between adsorbate and adsorbent. The plot
between log qe and log Ce is shown in Fig. 4. The values of the
Freundlich constants are calculated from the slope and intercept of
the line.