Abstract:

Zeolite is an extensively used inorganic material for control and remediation of heavy metal contaminated soil. In order to explore the passivation mechanism of Cu2+ by zeolite, the batch experiments were conducted to investigate adsorption thermodynamics and kinetics characteristics of Cu2+ in water solution onto zeolite. Results showed adsorption equilibrium data were well significantly fitted by Langmuir and Freundlich isotherms, and the process belonged to favorable adsorption. The theoretical saturated capacity was 3.839 g Cu/kg. Lagergren’s pseudo-second-order, Elovich and two-constant kinetic models were found to best represent the adsorption data, which was a rapid adsorption process. Kinetic analysis demonstrated the film liquid diffusion process was the essential rate-controlling step. Positive △H, △S and negative △G indicated the adsorption was spontaneous, endothermic and entropy driven.