where kf and n are the Freundlich constants. kf and n, determined from slop and intercept of the linear plot between ln qe and ln Ce,represent the adsorption capacity and adsorption intensity.The adsorption parameters of Langmuir and Freundlich isotherm are summarized in Table 4. Compared with Freundlich isotherm model, the Langmuir isotherm model yielded a higher correlation coefficient, which was higher than 0.988. Consequently,the Langmuir isotherm fitted the experimental data well, which illuminated that chemisorption mechanism was involved in this RhB adsorption process, the surface adsorption sites and sorption 2