An adsorption system was used to study the adsorption of Zn(Ⅱ) ion from chitosan derivatives

chitosan α-ketoglutaric acid(KCTS)and hydroxamated chitosan α-ketoglutaric acid(HKCTS).Experiments were carried out to study the effects of pH and concentration of Zn(Ⅱ) ion.It was found that the bonding between Zn(Ⅱ) and chitosan derivatives was in accordance with the Langmuir isotherm.The kinetic experimental data correlated well with the second-order kinetic model

indicating that the chemical sorption was the rate-limiting step.The apparent activation energy value of adsorption were 25.47 kJ·mol-1 and 5.473 kJ·mol-1 for KCTS and HKCTS respectively

and the sorption rate constant of Lagergren second-order sorption were 0.00311 g·mg-1·min-1 and 0.005 g·mg-1·min-1at 293 K

respectively.