摘要：Eight bacterial strains were isolated from lead-cadmium contaminated soil samples obtained from a Tungstenmine. Pb 2+ and Cd 2+ adsorption abilities of the isolated strains were screened. One isolate, referred to asStrains S, was selected for further study because of its relatively high adsorption ability. Five factors affectingadsorption of Pb 2+ and Cd 2+ were studied, namely, the initial concentration of Pb 2+ or Cd 2+ , temperature, pH,biomass of Strains S, and adsorption time. Results indicated that Strains S best adsorbed Pb 2+ when theinitial concentration of Pb 2+ was 100 mg/L, temperature was 35°C, pH was 6.5, dosage was 0.1 g, andadsorption time was 20 min. In contrast, Strain S best adsorbed Cd 2+ at an initial Cd 2+ concentration of 100mg/L, temperature of 40°C, pH 6.5, dosage of 0.1 g, and adsorption time of 20 min. The experimental datawere fitted to the Langmuir and Freundlich adsorption isotherm models, and the results indicated that theLangmuir model better fitted the experimental data. The results of infrared spectroscopy revealed that thefunctional groups involved in adsorption of Cd 2+ and Pb 2+ were -OH, -NH 2 , -S=O and -P=O. Using 16SrDNA sequencing and phenotypic properties test, Strains S was identified as Enterobacter sp.
