Synthesis and characterization of Mg-Fe layer double hydroxides and its application on adsorption of Orange G from aqueous solution

Layered double hydroxide (LDH) with hydrotalcite-like structure containing Mg(II) and Fe(III) in the layers and its calcined form were prepared at different Mg/Fe molar ration by co-precipitation method at fixed pH = 10 and followed by calcination at 500°C (denoted CLDH). The obtained materials were characterized by powder X-ray diffraction (PXRD), FT-IR spectroscopy, and TGA. The prepared LDH and CLDH were used for Orange G (Acid Orange 10) dye removal from aqueous solutions. Batch studies were carried out to address various experimental parameters such as contact time, pH, sorbent dose and temperature. The sorption kinetics data fitted the pseudo-second order model. The isotherms were established and the parameters calculated. The sorption data fitted the Langmuir model with good values of the correlation coefficient. The sorption capacity of CLDH was found to be almost independent on initial pH of solution in the range 3-13 and approximately 5 times higher than that of LDH. © 2011 Elsevier B.V.