BTEX Sorption by Organo-Clays: Cosorptive Enhancement and Equivalence of Interlayer Complexes

1. BTEX Sorption by Organo-Clays: Cosorptive Enhancement and Equivalence of Interlayer Complexes W. F. Jaynes and G. F. Vance Soil Science of America Journal 60:1742-1749 (1996) Anthony G. Benoit Lucas Hellerich

2. General Objectives of Organo-clay Research A clay mineral containing metal ions, such as Ca2+, in the interlayer space is exchanged with organic cations. The resulting organo-clay compound has a greatly increased capacity to sorb organic contaminants from various water and vapor phase sources. Research is underway to elucidate the properties and applications of organo-clays.

3. What is a Clay ? Sposito & Grasso, in press

4. Organic Cations Used in Study Designation Cation Name Formula mw + CDTMA cyclododecyltrimethylammonium C H N 226 15 32 + DTMA dodecyltrimethylammonium C H N 228 15 34 + HDTMA hexadecyltrimethylammonium C H N 285 19 42 + DDDMA didodecyldimethylammonium C H N 383 26 56 + DODMA dioctadecyldimethylammonium C H N 551 38 80 Table 1: Chemical Formulas and molecular weights (MW) of organic cations used in the study Taken from Jaynes and Vance, 1996

5. BTEX Mixture Up to 24 mL of BTEX mixture was added to 25 mL of distilled water: These proportions are consistent with 92 octane unleaded gasoline. Table 2: Contstituents of the BTEX mixture with Cwsat values.

6. There was no relationship between surface area and sorption Data from Jaynes & Vance, 1996