The MgAl hydrotalcite was modified by high-temperature calcination to obtain the modified MgAl hydrotalcite adsorbent.The adsorption performance of MgAl hydrotalcite for Zn2+was investigated by static adsorption experiments.The experimental results showed that the adsorption capacity of MgAl hydrotalcite for Zn2+was obviously improved through high-temperature calcination mod-ification,and the improvement degree was dependent on the calcination temperature.The MgAl hydrotalcite calcined at 600℃showed the highest adsorption capacity.The adsorption capacity of all MgAl hydrotalcites increased with the increase of adsorption time,initial Zn2+concentration and pH of solution.The adsorption of MgAl hydrotalcites calcined at lower than 200 ℃ and higher than 400 ℃ for zinc would meet the Langmuir and Freundlich isothermal model,respectively.The adsorption of all MgAl hydrotal-cites for Zn2+satisfied the pseudo-second-order kinetic equation.Zn2+was mainly deposited on the surface of MgAl hydrotalcite as Zn(OH)2 precipitation.
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