Synthesis and Sorption Studies of the Degradation of Congo Red by Ni-Fe Layered Double HydroxideAuthor(s): N. Ayawei, J. Godwin and D. Wankasi
Layered double hydroxide (Ni/Fe-CO3) was synthesized by co-precipitation method and characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopic (FTIR) and energydispersive X-ray spectroscopic (EDX) and applied for degradation of Congo red dye. The batch adsorption experiments were carried out to study the effect of various parameters, such as (CR) the initial concentration, contact time and temperature on adsorption properties of congo red onto the layered double hydroxide. The applicability of Langmuir, Freundlich, Dubinin-kaganer-Radushkevich and Temkin adsorption isotherm equations for the present system was also tested. The experimental data fitted all studied isotherm models with correlation coefficient values of 0.9995, 0.9973, 0.9982 and 0.9992, respectively. The kinetic studies showed that the adsorption data followed the pseudo-second order model. Thermodynamic studies indicated the adsorption of Congo red onto the layered double hydroxide was a spontaneous and endothermic process.