Adsorption of polyphenols in wastewater by organo-bentonites.

Organo-bentonites were prepared using hexadecyl trimethylammonium bromide (HDTMA) and benzyl triethylammonium chloride (BTEA). Both surfactants were used at two different rates of the cation exchange capacity (50% and 100%) of the bentonite. The organo-bentonites were characterised by small-angle X-ray scattering and used for the adsorption of polyphenols present in vegetable extracts (mimosa), which are employed in the tanning/retanning processes of leather manufacture. The adsorption capacity of the organo-bentonites was lower than that of activated charcoal. Enhanced adsorption capacities were observed for organo-bentonites prepared with higher amounts of the cationic surfactants.