The removal of zinc from aqueous solutions by natural bentonite

The equilibrium isotherms of zinc adsorption onto natural bentonite show that the data correlate well with Freundlich and Langmuir models and that the adsorption is physical in nature. The operating parameters (agitation speed, solid-liquid ratio, temperature, particle size and initial zinc concentration) influenced the rate of adsorption. The maximum monomolecular capacity Q0 according to the Langmuir model is 52.91 mg g−1 for an initial zinc concentration of 300 mg L−1 at 20°C.