Process Safety and Environmental Protection, Vol.77, No.2, 88-92, 1999
Adsorption of phenolic compounds from water by surfactant-modified pillared clays
An organophilic pillared clays-based adsorbent was prepared by incorporating a cationic surfactant, hexadecyltrimethylammonium (HDTMA) during the synthesis of conventional aluminium pillared clays. A specific amount of HDTMA was desired to occupy the cation exchange sites of the precursor clay. The presence of the HDTMA surfactant enhanced the adsorption ability of the clays toward phenolic compounds from aqueous systems. Adsorption experiments were carried out using a batch equilibration technique to investigate the removal of three toxic phenol compounds-phenol, 3-monochlorophenol and 3,5-dichlorophenol-by the surfactant-modified pillared clays. Comparative adsorption experiments were also conducted with Montmorillonite, the starting clay, as a reference material. The experimental results demonstrate the feasibility of utilizing surfactant-modified pillared clays as an adsorbent for removing phenol and chlorinated phenols from water. The adsorption affinity decreased in the following sequence: 3,5 dichlorophenol > 3-monochlorophenol > phenol. The Langmuir model was used to analyse the adsorption equilibria and calculate the adsorption capacity of phenolic compounds on these surfactant-modified pillared clays, S-PILCs.