REMOVAL OF REACTIVE RED 120 IN AQUEOUS SOLUTION USING Mg-HYDROTALCITES AS ADSORBENTS SOLIDS: KINETIC AND ISOTHERMS.

Reactive Red 120 is a widely used dye in the textile industry but their release in aqueous wastewater is a serious problem due to their toxicity and low biodegradability. The aim of this work was to evaluate the effect of the trivalent cation of magnesium-based materials type hydrotalcite as adsorbents applied to Reactive Red 120 dye removal in aqueous solution. The samples were synthesized by continuous coprecipitation and were characterized by surface area measurements, X-ray diffraction and temperature-programmed desorption of CO 2 . Dye adsorption tests were carried out using different adsorbent dosages and contact time. The kinetic adsorption were studied for the psudo-first ando pseudo-second models. The equilibrium adsorption data were fitted to the Langmuir, Freundlich and Redlich-Peterson isotherm models. The most suitable adsorption conditions were found at a residence time of 60 min and solid dosage of 2,5 g L-1 for HDL-MgFe, 2 g L-1 for HDL-MgAl and HC-Mg. The results showed that pseudo-second order model and the Langmuir and Redlich-Peterson models best described the removal process. The Al containing compound presented the best results due to a better interaction between strength and number of basic sites.