Abstract
Organo-clay can be utilized for the containment of environmentalpollutants originating from waste sites or accidental spills. Abatch study was conducted using organo-clays produced from aWyoming montmorillonite (SWy) and three organic cations(trimethylphenylammonium (TMPA), trimethylammonium adamantane(Adam), and hexadecyltrimethylammonium (HDTMA)) to characterizeBTEX (benzene, toluene, ethylbenzene, o-, m-, p-xylene) sorption. Sorption data were fitted to two models,with Freundlich resulting in greater correlations of the datathan the Langmuir model (R 2 at P ≤0.001-0.05). The Freundlich conditional index (n f),which describes the experimental sorption characteristics,decreased curvilinearly with organic-cation molecular weights,thus suggesting organo-clays with smaller cations had greaterhydrocarbon retention. Sorption of BTEX followed the order ofTMPA > Adam > HDTMA organo-clays. A similar sequence in themagnitudes of log K d and log K omsupportedthis finding. Positive log K om/K ow valuesfor TMPA and Adam derivatives indicated there was a greaterretention of BTEX by these organo-clays than octanol. The orderof log K om for SWy-HDTMA, although concentration-dependent, was analogous to the log K ow order,indicating partitioning was the dominant sorption mechanism forthe HDTMA-clay. Isotherms for SWy-TMPA and SWy-Adam followed aconvex up pattern. In contract, a concave up curvature, notedfor SWy-HDTMA isotherms, was probably caused by a cosorptiveenhancement process resulting from an effective increase in organic matter content of the organo-clay due to furtherhydrocarbon sorption,in concurrence with a decrease inadsorbate activity coefficients. Values of binding affinityconstant, K f, for SWy-TMPA were consistently higherthan SWy-Adam. The K f values determined for totalBTEX sorption by TMPA and Adam derivatives were higher thanthose for the individual hydrocarbons. With SWy-HDTMA, the same order was observed for benzene and toluene; however, ethylbenzene and xylenes had greater K f values thanthat for the BTEX mixture, possibly due to higher partitioningaffinity of the larger alkylbenzenes. With SWy-HDTM, thesequence of K f values was: ethylbenzene > m-xylene > p-xylene > o-xylene > toluene >benzene. Trends for SWy-TMPA and SWy-Adam were in contrast tothat of the partitioning order, suggesting that adsorption, ratherthan partitioning, was the primary sorption mechanism for thesetwo organo-clays. With respect to the equilibriumconcentrations, the sorbed amounts for total BTEX mixture weregenerally higher than those for the individual compounds. Ascompared to benzene and toluene, the large-size alkylbenzenesshowed greater partitioning affinity due to their high hydrophobicity.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Barcelona, M., Wehrman, A., Keely, J. F. and Pettyjohn, W. A.: 1990, Contamination of Ground Water: Prevention Assessment, Restoration, Noyes data corp., Park Ridge, N.J., 213 p.
Bowman, R. S., Haggerty, G. M., Huddleston, R. G., Neel, D. and Flynn, M. M.: 1995, 'Sorption of Nonpolar Organic Compounds, Inorganic Cations, and Inorganic Oxyanions by Surfactant-Modified Zeolites', in D. A. Sanatini, R. C. Knox, and J. H. Harwell, (eds.), Surfactant-Enhanced Subsurface Remediation: Emerging Technologies, ACS Symposium Series 594, American Chemical Society, Washington, D.C., pp. 54–64.
Brixie, J. M. and Boyd, S. A.: 1994, J. Environ. Qual. 23, 1283.
Burris, D. R. and Antworth, C. P.: 1990, Ground Water Manage. 4, 527.
Chiou, C. T.: 1989, 'Theoretical Considerations of the Partition Uptake of Nonionic Organic Compounds by Soil OrganicMatter', in B. L. Sawhney and K. Brown (eds.), Reactions and Movement of Organic Chemicals in Soils, Soil Science Society of America Special Publication No. 22. American Society of Agronomy, Madison, WI. pp. 1–30.
Giround, J. P. and Bonaparte, R.: 1989, Geotextiles and Geomembranes 8, 26.
Hewlett Packard: 1994, Electronic Pressure Control in Gas Chromatography, Hewlett Packard Corp., Palo Alto, CA, p. 117.
Jaynes, W. F. and Boyd, S. A.: 1990, J. Air Waste Manage. Assoc. 40, 1649.
Jaynes, W. F. and Boyd, S. A.: 1991, Clays Clay Miner. 39, 428.
Jaynes, W. F. and Vance, G. F.: 1996, Soil Sci. Soc. Am. J. 60, 1742.
Johnston, C. T.: 1996, 'Sorption of Organic Compounds on Clay Minerals: A Surface Functional Group Approach', in B. L. Sawhney, (ed.), Organic Pollutants in the Environments CMS Workshop Lextures, Vol. 8, The Clay Mineral Society, Boulder, CO, pp. 1–44.
Li, Y. and Gupta, G.: 1994, J. Haz. Mat. 38, 105.
Lo, I. M. C., Mak, R. K. M. and Lee, S. C. H.: 1997, J. Env. Eng. 123, 25.
March, J.: 1992, Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th edition, McGraw-Hill Inc., New York, NY, 1495 p.
Sheng, G., Xu, S. and Boyd, S. A.: 1997, Clays Clay Miner. 45, 659.
Sheng, G., Xu, S. and Boyd, S. A.: 1996, Water Res. 30, 1483.
Spurlock, F. C. and Biggar, J. W.: 1994, Thermodynamics of Organic Chemical Partition in Soils. 3. Nonlinear Partition from Water-Miscible Cosolvent Solutions, 28, 1003.
Stevens, J. J., Anderson, S. J. and Boyd, S. A.: 1996, Clays Clay Miner. 44, 88.
U.S. Environmental Protection Agency (USEPA): 1991, Revised Priority List of Hazardous Substances, Federal Register, 56(201): 52165–52175.
Wagner, J., Chen, H., Brownawell, B. J. and Westall, J. C.: 1994, Environ. Sci. Technol. 28, 231.
Xu, S., Sheng, G. and Boyd, S. A.: 1997, Advances in Agronomy, 59, 25.
Zytner, R. G.: 1994, J. Haz. Mat. 38, 113.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Sharmasarkar, S., Jaynes, W.F. & Vance, G.F. BTEX Sorption by Montmorillonite Organo-Clays: TMPA, Adam, HDTMA. Water, Air, & Soil Pollution 119, 257–273 (2000). https://doi.org/10.1023/A:1005167524630
Issue Date:
DOI: https://doi.org/10.1023/A:1005167524630