Chinah i g h l i g h t s•Activated carbon treated by KOHexhibited better adsorption proper-ties than untreated one.•Thermodynamic parameters demon-strated the adsorption process wasspontaneous and favorable.•It was probable to deduce adsorptionmechanisms and design adsorptionsystems by the study of adsorptionkinetics, isotherms and thermody-namics.