SORPTION OF BENZENE AND NAPHTHOL TO ORGANOBENTONITES INTERCALATED WITH SHORT CHAIN CATIONIC SURFACTANTS

Abstract

This work studies the sorption of benzene and naphthol by bentonites exchanged with quaternary ammonium surfactants tetramethylammonium (TMA) ion, benzyltrimethylammonium (BTMA) ion, tetraethylammonium (TEA) ion, and benzyltriethylammonium (BTEA) ion to elucidate how exchanged short chain organic cations affect the mechanistic function of the modified bentonite. Local high charge density areas are found at interlamellar surfaces of bentonite and intercalated short chain organic cations aggregate preferentially at these sites to form organic carbon phase effective in nonionic organic compounds (NOC) uptake. Experimental results indicate that the amount of benzene uptake decreases as the size of intercalated organic cation increases from TMA to BTMA to TEA to BTEA, presumably due to the different structures of organic carbon phase formed in organobentonite. In addition, benzene sorption capacity of organobentonite modified with short chain organic cation is highly sensitive to the cation exchange capacities (CEC) of bentonite used.

Keywords:

• Sorption
• Organobentonite
• Benzene
• Naphthol
• Organic cation

ACKNOWLEDGMENTS

The author thanks the National Science Council of the R.O.C. for financially supporting this study. Ms. C. C. Huang is appreciated for her technical assistance.