Mg/Fe Layered Double Hydroxide as a Novel Adsorbent for the Removal of Congo red
Ayawei, N, Angaye S. S; Wankasi, D

Abstract
The ability of Mg/Fe- CO3 to degrade Congo Red in aqueous solution was investigated under various experimental conditions. The layered double hydroxide was synthesized by co-precipitation method and characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopic (FTIR) and Energy- Dispersive X-ray Spectroscopic (EDX). Batch mode experiments were conducted to assess the potential of the layered double hydroxide for the removal of Congo Red from aqueous solution. Laboratory experimental investigation was carried out to identify the effect of agitation time (10 - 30min), varying temperature (40-80˚C) and varying concentration (20 - 40m/L). The adsorption was endothermic and the computation of the parameters ΔG˚, ΔH˚, ΔS˚ and ΔHx indicated that the interactions were thermodynamically favorable. Langmuir, Freundlich, Temkin and the Dubinin–Kaganer–Radushkevich (DKR) adsorption isotherm models were used to qualify the experimental data with the best fits been Langmuir and Freundlich isotherms with regression coefficient values of 0.9995 and 0.9998 respectively.

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