Synthesis and Characterization of Low-Cost Adsorbent and used for Alizarin Yellow GG and Alizarin Red S Dyes Removal from Aqueous Solutions

The effective use of a synthetic clay as ionic solid adsorbent for the removal of alizarin yellow GG and alizarin red S from aqueous solutions was investigated as low-cost adsorbent. Anionic clay of layered double hydroxide (LDH) was prepared from the salts of magnesium-aluminium nitrate in a ratio of (5:1) by co-precipitation method, characterized by X-ray diffraction (XRD), FT-IR spectroscopy and thermogravimetric analysis (TGA) to confirm the presence of LDH. The effect of various experimental parameters like contact time, initial and concentrations were investigated. The experiments were carried out in a batch system to optimize operation variables. The Langmuir and Freundlich isotherm equations applied to the data and the isotherm analysis indicated that the equilibrium was fitted to both of Freundlich and Langmuir. The models showed physio – chemical sorption for both of Alizarine yellow GG and Alizarin Red S on LDH surface. Kinetics study was made using lagergreen equations and the results show that the sorption of Alizarine Yellow GG and Red dye uptake on layered double hydroxide (LDH) were fitted with both pseudo-first order until the adsorption reach equilibrium, then, they fellow pseudo second order where the adsorption rates depend on the amount of adsorbent and concentration of adsorbate. The partition coefficient Kd for the sorption of alizarine yellow GG and alizarin red S on LDH were also determined and it was indicated that the value of Kd increases with time until equilibrium is reached and becomes constant because of the extra unoccupied sites until the adsorption reaches equilibrium.