ADSORPTION OF FLUORIDE FROM AQUEOUS SOLUTION BY Mg-Al HYDROTALCITE

In this study,Mg-Al hydrotalcites(LDHs)were prepared by hydrothermal method and the adsorption of fluoride onto the LDHs and its calcined product(C-LDHs)was investigated.XRD and TG were used to characterize the LDHs,C-LDHs and fluoride adsorbed C-LDHs(R-LDHs).Results show that fluoride adsorption onto the LDHs is negligible,while good sorption of fluoride onto the C-LDH is achieved.The fluoride uptake onto the C-LDHs was further enhanced under acidic solution.The study of adsorption kinetics indicated that the adsorption equilibrium of fluoride onto the C-LDH was achieved in 4h.In addition,the structure of C-LDHs shifted to layer structure of LDHs after the fluoride adsorption,indicating that the memory effect of C-LDHs accounted for the effective removal of aqueous fluoride.