Mg-Al Hydrotalcites Intercalated by Ethylenediaminetetraacetic Acid for Ni(II) Removal from Aqueous Solution

High-efficient-adsorbents-layered double hydroxides (LDH) intercalated by carbonate ion and ethylenediaminetetraacetic acid (EDTA) ion were synthesized by the coprecipitation method for the removal of Ni2+ in the aqueous solution. MgAl EDTA LDH had a better adsorption performance than MgAl-CO3-LDH due to the larger specific surface area and strong trapping for heavy metal ions of EDTA. Ni(II) adsorption on the two kinds of LDH conformed to the pseudo-second-order kinetic model. The Langmuir isothermal adsorption model was more suitable to describe the adsorption isotherm than the Freundlich model. The maximum adsorption capacity of MgAl EDTA LDH and MgAl-CO3-LDH for Ni(II) was 108.2 and 23.47 mg/g, respectively. This work may offer ideas for the preparation and application of excellent adsorbents in the heavy metal removal from polluted water.