Adsorption study of chlorophenol red on calcined hydrotalcite
The color removal from aqueous solutions of chlorophenol red by adsorption on a calcined synthetic hydrotalcite was investigated. The solid [Mg-Al-CO3] was prepared by coprecipitation at constant pH and with an Mg/Al molar ratio of 2. The studies by X-ray diffraction (XRD) and infrared spectroscopy FTIR (Fourier Transform InfraRed spectroscopy) have shown that the material obtained corresponds to the hydrotalcite-like compounds with good crystallinity. The interaction dye-hydrotalcite shows that the kinetic of adsorption is fast and follows the second order model. The effects of the pH, adsorbent concentration, chlorophenol red concentration and competitive ions such as chloride and carbonate on the adsorption were studied. Solutions containing from 0.015 to 1.5 mmol∙L-1 of chlorophenol red were successfully treated. The adsorption capacity of the calcined hydrotalcite is close to 1.7 mmol∙g-1. This suggests that the calcined hydrotalcites could constitute interesting supports for the trapping of chlorophenol red.