In order to fully understand adsorption nature of Cu2 + , Zn2 + , Pb2 + , Cd2 + , Mn2 + , Fe3+ onto natural diatomite, and to find problems of classical isothermal adsorption models' application in liquid/solid system, a series of isothermal adsorption tests were conducted. As results indicate, the most suitable isotherm models for describing adsorption of Pb2 + , Cd2. , Cu2 + , Zn2 + , Mn2 + , Fe3 + onto natural diatomite are Tenkin, Tenkin, Langmuir, Tenkin, Freundlich and Freundlich, respectively, the adsorption of each ion onto ...