镁铝层状双金属氢氧化物对Cu^2+和Cd^2+的吸收动力学研究

Kinetics of uptake of Cu^2+and Cd^2+by Mg-Al layered double hydroxides

研究了柠檬酸盐(C6H5O7^3-)、苹果酸盐(C4H4O5^2-)和酒石酸盐(C4H4O6^2-)插层的镁铝层状双金属氢氧化物(MgAl-LDHs)对Cu^2+、Cd^2+的吸收动力学。当将MgAl-LDHs加入到恒定pH=5.0的Cu^2+和Cd^2+溶液中时,Cu^2+和Cd^2+的浓度随着温度的升高而降低。结果表明,对重金属离子的吸收主要归因于重金属离子与有机酸阴离子之间发生了螯合作用,并发现吸收速率方程取决于形成的螯合物的类型。

The kinetics of the uptake of Cu^2+and Cd^2+by Mg-Al layered double hydroxides(MgAl-LDHs)intercalated with citrate 3-(C6H5O7^3-),malate 2-(C4H4O5^2-),and tartrate 2-(C4H4O6^2-)in the interlayer were examined.When the MgAl-LDHs were added to Cu^2+and Cd^2+solutions of a constant pH of 5.0,the concentrations of Cu^2+and Cd^2+decreased with increasing temperature.The uptake was shown to occur as chelation between the heavy metal ions and the organic acid anions.The uptake rate equation was found to be dependent on the type of chelate formed.