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A variable charge mineral(kaolinite)and constant charge mineral(montmorillonite)were selected as representative soil components,and a biosurfactant,saponin,was investigated for its potential to remove Pb(Ⅱ),Zn(Ⅱ)from them to study the adsorption of Pb(Ⅱ)and Zn(Ⅱ)ions onto kaolin and montmorillonite as a function of initial concentration and to explore the optimal conditions for desorption to the two ions such as pH and concentration of saponin.Results showed that under the same initial concentration of Pb(Ⅱ),the equilibrium adsorption capacity were montmorillonite(145.35mmol ? Kg-1)> kaolinite(61.25 mmol ? Kg-1),while for Zn(Ⅱ),montmorillonite(103.96mmol?kg-1)> kaolinite(35.76 mmol?kg-1).Generally,with the increase of saponin concentration(1-20g?L-1),the desorption efficiency of metals increased,and expressed as kaolinite > montmorillonite.The highest Pb(Ⅱ)desorption efficiency by the surfactant was obtained at a saponin concentration of 10g/L and found to be 19.63%for montmorillonite and 22.63%for kaolinite,further increase the concentration of saponin had no significant effect on desorption efficiency.While the highest Zn(Ⅱ)desorption efficiency was found to be 75.38%for montmorillonite and 79.13%for kaolinite at a saponin concentration of 20g?L-1.During Pb(Ⅱ)desorption process,the highest efficiency was abtained at pH 3.0.However,the effect of pH on Zn(Ⅱ)desorption was not the same: at lower saponin concentration(<10g?L-1),the desorption efficiency of pH 3.0 system was slightly lower than pH 5.0 system,and when saponin concentration increased(> 10g?L-1),the desorption efficiency of pH 3.0 system was higher than that of pH 5.0 system.