The corncob was microwave-assistedly modified by KMnO4 and used for adsorption of U(Ⅵ)ions from aqueous solution.The kinetics and thermodynamics of their adsorption were measured using batch experiments.The results show that the kinetics of adsorption follows well the pseudo-second order equation

indicating that the uranium adsorption by the modified corncob is mainly chemisorption. The Langmuir

Freundlich and D-R isothermal adsorption models were used to relate the equilibrium data

finding that Langmuir isotherm of monolayer adsorption is better fitting them

pointing out that the adsorption mainly occurs on surface active sites of modified corncob.The values of apparent activation energy Ea and average adsorption energy Es support also the suggestion that adsorption of U(Ⅵ) on modified corncob is mainly chemisorption

although some physical adsorption can not be got rid of.The thermodynamic parameters(ΔH

ΔS and ΔG)calculated from the adsorption isotherms at various temperatures indicated that the adsorption of U(Ⅵ)on modified corncob is an endothermic

spontaneous process and more favorable at higher temperature.