Stabilization mechanism of Friedel's salt on Pb2+

To study the stabilization ability and mechanism of of Pb2+ on Friedel's salt (Ca2Al(OH)6 (CI, OH)·2 H2O), its equilibrium adsorption and adsorption kinetics were evaluated by isothermal adsorption experiments. Improved TCLP and desorption experiments were used to study the chemical stability of Pb2+-doped Friedel's salt. The phases and microstructures of heavy metal-substituted Friedel's salt were characterized by XRD and FTIR. Based on these results, mechanisms of stabilization of Pb2+ on Friedel's salt are suggested.