Removal of Cd^2+ from Aqueous Solution Using MgAlCO_3-Layered Double Hydroxide

Anion clay hydrotalcite MgAlCO3 with a Mg/Al molar ratio of 3:1 was synthesized by co-precipitation at room temperature and pressure. The physicochemical properties were evaluated using Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA). The efficacy of anion clay hydrotalcite in the removal of Cd^2+ from aqueous solutions was investigated with respect to contact time, initial concentration, pH, adsorbent dosage and temperature. The Cd^2+ removal increased with the increased in contact time, adsorbent dosage, pH and initial concentration. Adsorption decreases with increasing initial concentration and temperature, for which the latter is indicative of an exothermic process. The equilibrium adsorption capacity of MgAlCO_3 was evaluated using linear Langmuir and Freundlich isotherms with respect to the separation factor, R_L.