Synthesis of the Mg-Al hydrotalcite and its adsorption properties for VO₃^-

Mg-Al-CO₃^2- hydrotalcite was prepared by hydrothermal method and then calcined. The adsorption behaviors of hydrotalcite for VO₃^- in the solution before and after calcination were investigated. The results were summarized as follows: The maximum adsorption capacity of hydrotalcite C-HT after calcination for VO₃^- is 95.21 mg/g at 35 ℃, much lager than that of hydrotalcite before calcination which is 31.59 mg/g. It shows significant influence of calcination on the adsorption capacity of hydrotalcite. The kinetics of VO₃^- adsorption onto CHT shows that the time until equilibrium is 6 hour, and C-HT after adsorption is reproducible by desorption of sodium carbonate solution with desorption efficiency of up to 97 %. The adsorption capacity of C-HT for VO₃^- in the solution is mainly due to the exchange adsorption of VO₃^- and the CO₃^2- filling between the layers.