摘要
Pb2+ and Cd2+ in leachate were adsorbed on clay-solidified grouting curtain for waste landfills with equilibrium experiment. The cation exchange capacity was determined with ammonium acetate. And the concentration of heavy metal cations in leachate was determined with atomic absorption spectrophotometer. Their equilibrium isotherms were measured, and the experimental isotherm data were analyzed by using Freundlich and Langmuir models. The results show that the adsorption capacities of the heavy metal cations are closely related to the compositions of clay-solidified grouting curtain, and the maximum adsorption appears at the ratio of cement to clay of 2∶4 in the experimental conditions. At their maximum adsorption and pH 5.0, the adsorption capacities of Pb 2+ and Cd 2+ are 16.19mg/g and 1.21mg/g. The competitive adsorption coefficients indicate that the adsorption of clay-solidified grouting curtain for Pb2+ is stronger than that for Cd 2+ . The adsorption process conforms to Freundlich’s model with related coefficient higher than 0.996.
Pb^2+ and Cd^2+ in leachate were adsorbed on clay-solidified grouting curtain for waste landfills with equilibrium experiment. The cation exchange capacity was determined with ammonium acetate. And the concentration of heavy metal cations in leachate was determined with atomic absorption spectrophotometer. Their equilibrium isotherms were measured, and the experimental isotherm data were analyzed by using Freundlich and Langmuir models. The results show that the adsorption capacities of the heavy metal cations are closely related to the compositions of clay-solidified grouting curtain, and the maximum adsorption appears at the ratio of cement to clay of 2 : 4 in the experimental conditions. At their maximum adsorption and pH 5.0, the adsorption capacities of Pb^2+ and Cd^2+ are 16.19 mg/g and 1.21 mg/g. The competitive adsorption coefficients indicate that the adsorption of clay-solidified grouting curtain for Pb^2+ is stronger than that for Cd^2+. The adsorption process conforms to Freundlich's model with related coefficient higher than 0. 996.
基金
Project (200065) supported by University Key Teacher Foundation of the Ministry of Education of China
关键词
吸附
重金属
土壤污染
浸出液
污染治理
adsorption
clay-solidified grouting curtain
Pb^2+
Cd62+
Freundlich model
leachate treatment