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Abstract
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We report the preparation and characterization of a layered
double hydroxide (LDH) adsorbent for azoic dye, metanil yellow (yellow
GX; YGX) removal. The nanoparticles of Mg-Fe-LDH-NO3 adsorbent
were prepared with Mg/Fe molar ratio of 3:1 by a hydrothermal
process and coprecipitation method at pH 9.5 and were characterized
by X-ray powder diffraction (XRPD), thermal gravimetric
analysis (TGA), elemental analysis, and Fourier transform infrared
spectroscopy (FT-IR). The size and morphology of nanoparticles were examined by scanning electron microscopy (SEM). The XRD patterns
indicate that the intercalation of YGX between the LDH layers has
not occurred and surface adsorption has happened. In the adsorption
experiments, the Gibbs free energy ΔG0 values, the enthalpy ΔH0, and
entropy ΔS0 was determined. The isotherms showed that the adsorption
of YGX by Mg-Fe-LDH-NO3 was both consistent with Langmuir and
Freundlich equations.
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