Hydrotalcite-like compounds as potential sorbents of phenols from water

Hydrotalcite-like compounds, being anti-types of clay minerals, are potential sorbents for polar and anionic molecules. This work summarizes the experimental results of adsorption—desorption of two phenols (trichlorophenol, TCP, and trinitrophenol, TNP) on an hydrotalcite (HT) and its calcined product (HT500). Both phenols are adsorbed on HT by anion exchange, but TNP adsorption was much higher than that of TCP due to their different pKa. The adsorption of both phenols on HT500 occurs by the reconstruction of the layered structure, TNP being also adsorbed at more than TCP. These adsorption mechanisms were confirmed by X-ray diffraction, IR spectroscopy and TG-DTA analysis of the HT-TCP and HT-TNP products. Results presented here indicate HT500 as potential sorbent for phenols from waters, and that its recyclability is possible.