Synthesis and Sorption Studies of Lead (II) on Zn/Fe Layered Double Hydroxide

Abstract

Zn/Fe-CO3 layered double hydroxide was synthesis by co-precipitation method for the adsorption of lead ions in aqueous solution. The synthesized layered double hydroxide (Zn/Fe-CO3) was then characterized by Powder X-ray Diffraction (PXRD), Fourier Transform Infrared (FT-IR) and SEM/EDX analysis. The experimental data fitted both Langmuir and Freundlich isotherms with regression correlation coefficient values of 0.9999 and 0.999 respectively. The essential thermodynamic parameters of Ho, So, Hx and Eawere calculated to be -4.8327KJ/mol, 12.8J/molK, 13.3KJ/mol and -1.948KJ/mol, thus showing the exothermic nature of the process and the randomness of the system. The low activation energy (Ea) value is consistent with physical adsorption. The results also fitted zero-order kinetic, first-order kinetic and pseudo-second order models.