Cosolvency and Sorption of Hydrophobic Organic Chemicals

摘要

Sorption of hydrophobic organic chemicals (HOCs) by two soils was measured frommixed solvents containing water plus completely miscible organic solvents (CMOSs) and partially miscible organic solvents (PMOSs). The utility of the log-linear cosolvency model for predicting HOC sorption from solvent mixtures was evaluated. Co-solvent effects of PMOSs on HOC solubility and sorption were compared. Nonpolar PMOSs (such as toluene, p-xylene, and TGE) have low aqueous solubilities and when present either as a cosolvent/cosolute in the aqueous phase or as a separate liquid phase do not significantly influence HOC sorption by soils. In contrast, polar PMOSs (such as nitrobenzene and o-cresol) have sufficiently high aqueous solubilities that significant decreases in HOC sorption can be measured. The presence of a CMOS increases the PMOS solubility which in turn, is reflected in increased solubility and decreased sorption of HOCs. (Copyright (c) by the American Chemical Society, 1990.)