Tricaprylmethylammonium bentonite complexes as adsorbents for benzene, toluene, ethylbenzene and xylene

An organoclay complex was synthesized from a sodium bentonite and tricaprylmethylammonium chloride (TCMA), the latter at about 30 per cent of the cation-exchange capacity of the bentonite. Batch adsorption isotherms with aromatic hydrocarbons were measured, allowing 24 h for equilibrium. Analysis was by high performance liquid chromatography. The adsorbents were also characterized by Fourier Transform infrared spectra. The high adsorption of the hydrocarbons from aqueous solution by TCMA-bentonite was related to their hydrophobicity and water solubility. The adsorbents showed greatest affinity for the larger molecules. The average free swell volume of the compounds was smaller for the TCMA-modified adsorbents. Apart from treating contaminated waters, the adsorbents might be useful in liner clay systems to overcome problems from the attack of organic contaminants on pure clays.