Pseudo first-order , pseudo second-order models were used to fit the experimental data. The Lagergren pseudo first-order model is generally expressed in the linear form log(qe-qt) log(de) kit/2.303(3) where qe and qu(mg g 1) are the amounts of adsorbate at equilibrium and at time t(s), respectively and ku(s 1) is the constant rate. A linear plot of log(q qt) versus t gives information about whether the kinetic model is compatible with adsorption data. qe and ki can be acquired from the intercept and the slope, respectively. If the intercept is not close to qe, the process does not follow the pseudo first-order model even with a fairly high correlation coefficient.