Removal of Cu2+ from the aqueous solution by tartrate-intercalated layered double hydroxide

The tartrate-intercalated MgAl layered double hydroxide (MgAl-TA LDH) was prepared by ion-exchange method at the acid solution using MgAl-CO3 LDH as the precursor. The adsorption of Cu2+ on MgAl-TA LDH was studied and some influence factors such as contact time, initial Cu2+ concentration, adsorbent dosage, solution pH, and adsorption temperature were investigated. Three kinds of adsorption isotherms (Langmuir model, Freundlich model, and Redlich-Peterson model) were investigated; the results indicated that equilibrium was well described by Langmuir isotherm, predicting the adsorption of Cu2+ on MgAl-TA adsorbents was a monolayer adsorption. The equilibrium kinetic adsorption data were fitted to the pseudo-second order kinetic equation. Furthermore, the adsorption of Cu2+ was controlled mainly by chemical process combined with intra-particle diffusion. Parameters of adsorption thermodynamic suggested that the interaction of Cu2+ adsorbed by MgAl-TA LDH adsorbents was spontaneous and endothermic.