MgAl-CO3 hydrotalcites with different Mg/Al mole ratios were prepared by co-precipitation method, and calcined to get the calcined samples. The adsorption capacity of trace perchlorate ion from water on calcined samples was measured, the influence of initial perchlorate concentration, varying pH of solution, temperature, particle size, and co-existed anions concentration on the adsorption capacity of calcined samples were studied, kinetic parameters were obtained. Results showed that the best synthesis conditions to maximize the perchlorate adsorption capacity of the calcined MgAl-CO3 layered double hydroxides are the calcination temperature of 550 ℃ and n(Mg2+)/n(Al3+), which fit well with second-order kinetic equation and Freundlich isotherm model. It could be used as a buffer. in a wide range of pH But in strong acid conditions, the calcined hydrotalcite may be dissolved, while in strong alkali condition, the perchlorate removal was lower as a consequence of the competition between OH- and ClO4-.
