Removal of Pb2+ and Cd2+ by adsorption on clay-solidified grouting curtain for waste landfills

Abstract

Pb z+ and Cd z+ 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 z+ is stronger than that for Cd 2+. The adsorption process conforms to Freundlich's model with related coefficient higher than 0. 996.

The Impact of Double Skin Facade on Building Energy Consumption in Daylighting Control Mode

“…The DSF originated in the 1990s in Europe, especially in Germany is widely used. It appears a little later in China and the first case is Beijing National Accounting Institute Teaching Building in June 2000 [1]. With the development of economy, there are more and more office buildings using DSF which is artistic and can make people work as efficiently as possible.…”