Kinetics of adsorption of Zn(II) ion on chitosan derivatives

The adsorption of Zn(II) ions from aqueous solution by chitosan derivatives (KCTS and HKCTS) was studied in a batch adsorption system. The adsorption capacities and rates of Zn(II) ions onto chitosan derivatives were evaluated. The adsorption isothermal data could be well interpreted by the Langmuir and Freundlich models. The kinetic experimental data properly correlated with the second-order kinetic model, which indicates that the chemical adsorption is the rate-limiting step. The apparent adsorption activation energy were 25.47 kJ mol^? and 5.473 kJ mol^?, respectively, and the second-order adsorption constant for KCTS and HKCTS were 0.00311 g (mg min)^?1 and 0.005 g (mg min)^?1, respectively.