Effects of polar and nonpolar groups on the solubility of organic compounds in soil organic matter

Environmental Science & Technology
By:  and 

Links

Abstract

Vapor sorption capacities on a high-organic-content peat, a model for soil organic matter (SOM), were determined at room temperature for the following liquids: n-hexane, 1,4-dioxane, nitroethane, acetone, acetonitrile, 1-propanol, ethanol, and methanol. The linear organic vapor sorption is in keeping with the dominance of vapor partition in peat SOM. These data and similar results of carbon tetrachloride (CT), trichloroethylene (TCE), benzene, ethylene glycol monoethyl ether (EGME), and water on the same peat from earlier studies are used to evaluate the effect of polarity on the vapor partition in SOM. The extrapolated liquid solubility from the vapor isotherm increases sharply from 3-6 wt % for low-polarity liquids (hexane, CT, and benzene) to 62 wt % for polar methanol and correlates positively with the liquid's component solubility parameters for polar interaction and hydrogen bonding. The same polarity effect may be expected to influence the relative solubilities of a variety of contaminants in SOM and, therefore, the relative deviations between the SOM-water partition coefficients (Kom) and corresponding octanol-water partition coefficients (Kow) for different classes of compounds. The large solubility disparity in SOM between polar and nonpolar solutes suggests that the accurate prediction of Kom from Kow or Sw (solute water solubility) would be limited to compounds of similar polarity.

Publication type Article
Publication Subtype Journal Article
Title Effects of polar and nonpolar groups on the solubility of organic compounds in soil organic matter
Series title Environmental Science & Technology
DOI 10.1021/es00055a026
Volume 28
Issue 6
Year Published 1994
Language English
Publisher ACS
Contributing office(s) Toxic Substances Hydrology Program
Description 6 p.
First page 1139
Last page 1144
Google Analytic Metrics Metrics page
Additional publication details