Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-07T13:31:44.242Z Has data issue: false hasContentIssue false

Relation of Water and Neutral Organic Compounds in the Interlayers of Mixed Ca/Trimethylphenylammonium-Smectites

Published online by Cambridge University Press:  28 February 2024

Guangyao Sheng
Affiliation:
Department of Crop and Soil Sciences, Michigan State University, East Lansing, Michigan 48824
Stephen A. Boyd
Affiliation:
Department of Crop and Soil Sciences, Michigan State University, East Lansing, Michigan 48824
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Organoclays were prepared by exchanging Ca2+ in a Ca2+-saturated smectite partially or fully with trimethylphenylammonium (TMPA) cations. The mechanistic function of these organoclays as adsorbents for neutral organic compounds in aqueous solution was examined. TMPA cations were found to take a random distribution on the surfaces of mixed Ca/TMPA-smectites. The presence of TMPA, and its random distribution, resulted in water associated with the clay surfaces being held more weakly. Apparently, the interspersing of TMPA and Ca2+ ions prohibits the formation of a stable network of water molecules around Ca2+. Water molecules associated with the siloxane surface in mixed Ca/TMPA-clays are removed during the adsorption of neutral organic compounds from bulk water, leaving only ∼11 strongly held water molecules around each Ca2+, as opposed to ∼58 water molecules in homoionic Ca2+-smectite. These results demonstrate that the amount of water associated with the clay surfaces and interlayers depends on the nature of the exchange cation(s), and not on the amount of available siloxane surface area by itself. We conclude that in TMPA-smectites the TMPA cations function as nonhydrated pillars, and sorption of organic solutes occurs predominantly on the adjacent siloxane surfaces, which are hydrophobic in nature. The water molecules around Ca2+ in mixed Ca/TMPA-smectites obscures some of the siloxane surfaces. This diminishes sorption capacity, in an amount roughly equivalent to the fraction of the CEC occupied by Ca2+, because organic solutes cannot displace the waters of hydration of Ca2+.

Type
Research Article
Copyright
Copyright © 1998, The Clay Minerals Society

References

Boyd, S.A. Jaynes, W.F. and Ross, B.S., 1991 Immobilization of organic contaminants by organo-clays: Application to soil restoration and hazardous waste containment Organic substances and sediments in waters 1 181200.Google Scholar
Boyd, S.A. Lee, J.-F. and Mortland, M.M., 1988 Attenuating organic contaminant mobility by soil modification Nature 333 345347 10.1038/333345a0.CrossRefGoogle Scholar
Boyd, S.A. Mortland, M.M. and Chiou, C.T., 1988 Sorption characteristics of organic compounds on hexadecyltrimethylam-monium-smectite Soil Sci Soc Am J 52 652657 10.2136/sssaj1988.03615995005200030010x.CrossRefGoogle Scholar
Boyd, S.A., Sun, S., Lee, J.-F. and Mortland, M.M.. 1988. Pentachlo-rophenol sorption by organo-clays. Clays Clay Miner 36: 125130.CrossRefGoogle Scholar
Burris, D.R. and Antworth, C.P., 1992 In-situ modification of aquifer material by a cationic surfactant to enhance retention of organic contaminants J Contam Hydrol 10 325327 10.1016/0169-7722(92)90014-6.CrossRefGoogle Scholar
Call, F., 1957 The mechanism of sorption of ethylene dibro-mide on moist soils J Sci Food Agric 8 630639 10.1002/jsfa.2740081106.CrossRefGoogle Scholar
Chiou, C.T. Peters, L.J. and Freed, V.H., 1979 A physical concept of soil-water equilibria for nonionic organic compounds Science 206 831832 10.1126/science.206.4420.831.CrossRefGoogle ScholarPubMed
Chiou, C.T. Porter, P.E. and Schmedding, D.W., 1983 Partition equilibria of nonionic organic compounds between soil organic matter and water Environ Sci Technol 17 227231 10.1021/es00110a009.CrossRefGoogle Scholar
Gregg, S.J. and Sing, K.S.W., 1982 Adsorption, surface area, and porosity New York Academic Pr.Google Scholar
Hunt, J.P., 1965 Metal ions in aqueous solution W. A. Benjamin New York 16.Google Scholar
Hanson, W.J. and Nex, R.W., 1953 Diffusion of ethylene dibromide in soil Soil Sci 76 209214 10.1097/00010694-195309000-00005.CrossRefGoogle Scholar
Jaynes, W.F. and Boyd, S.A., 1990 Trimethylphenylammonium-smectite as an effective adsorbent of water soluble aromatic hydrocarbons J Air Waste Manage Assoc 40 16491653 10.1080/10473289.1990.10466811.CrossRefGoogle ScholarPubMed
Jaynes, W.F. and Boyd, S.A., 1991 Hydrophobicity of siloxane surfaces in smectite as revealed by aromatic hydrocarbon adsorption from water Clays Clay Miner 39 428436 10.1346/CCMN.1991.0390412.CrossRefGoogle Scholar
Kukkadapu, R.K. and Boyd, S.A., 1995 Tetramethylphosphonium-and tetramethylammonium-smectites as adsorbents of aromatic and chlorinated hydrocarbons: Effect of water on adsorption efficiency Clays Clay Miner 43 318323 10.1346/CCMN.1995.0430306.CrossRefGoogle Scholar
Lee, J.-F. Mortland, M.M. Boyd, S.A. and Chiou, C.T., 1989 Shape-selective adsorption of aromatic molecules from water by tetramethylammonium-smectite J Chem Soc, Faraday Trans 1 85 29532962 10.1039/f19898502953.CrossRefGoogle Scholar
Lee, J.-F. Mortland, M.M. Chiou, C.T. Kile, D.E. and Boyd, S.A., 1990 Adsorption of benzene, toluene, and xylene by two tetramethylammonium-smectites having different charge densities Clays Clay Miner 38 113120 10.1346/CCMN.1990.0380201.CrossRefGoogle Scholar
McBride, M.B., 1994 Environmental chemistry of soils New York Oxford Univ Pr. 344.Google Scholar
McBride, M.B. and Mortland, M.M., 1973 Segregation and exchange properties of alkylammonium ions in a smectite and vermiculite Clays Clay Miner 21 323329 10.1346/CCMN.1973.0210508.CrossRefGoogle Scholar
Mortland, M.M. Sun, S. and Boyd, S.A., 1986 Clay-organic complexes as adsorbents for phenol and chlorophenols Clays Clay Miner 34 581585 10.1346/CCMN.1986.0340512.CrossRefGoogle Scholar
Nye, J.V. Guerin, W.F. and Boyd, S.A., 1994 Heterotrophic activity of microorganisms in soils treated with quaternary ammonium compounds Environ Sci Technol 28 944951 10.1021/es00054a029.CrossRefGoogle ScholarPubMed
Sheng, G. Xu, S. and Boyd, S.A., 1996 Mechanisms controlling sorption of neutral organic contaminants by surfactant derived and natural organic matter Environ Sci Technol 30 15531557 10.1021/es9505208.CrossRefGoogle Scholar
Sheng, G. Xu, S. and Boyd, S.A., 1996 Surface heterogeneity of trimethylphenylammonium-smectite as revealed by adsorption of aromatic hydrocarbons from water Clays Clay Miner 45 659669 10.1346/CCMN.1997.0450505.CrossRefGoogle Scholar
Spencer, W.F. and Cliath, M.M., 1970 Desorption of lindane from soil as related to vapor density Soil Sci Soc Am Proc 34 574578 10.2136/sssaj1970.03615995003400040012x.CrossRefGoogle Scholar
Spencer, W.F. Cliath, M.M. and Farmer, W.J., 1969 Vapor density of soil-applied dieldrin as related to soil-water content, temperature, and dieldrin concentration Soil Sci Soc Am Proc 33 509511 10.2136/sssaj1969.03615995003300040010x.CrossRefGoogle Scholar
Stark, F.L. Jr., 1948 Investigations of chloropicrin as a soil fumigant New York (Cornell) Agr Exp Sta Mem 178 161.Google Scholar
Xu, S. and Boyd, S.A., 1994 Cation exchange chemistry of hexade-cyltrimethylammonium in a subsoil containing vermiculite Soil Sci Soc Am J 58 13821391 10.2136/sssaj1994.03615995005800050015x.CrossRefGoogle Scholar
Xu, S. and Boyd, S.A., 1995 Cationic surfactant sorption to a ver-miculitic subsoil via hydrophobic bonding Environ Sci Technol 29 312320 10.1021/es00002a006.CrossRefGoogle ScholarPubMed