Aromatic Compound Solubility in Solvent/Water Mixtures

Abstract

The solubility of various aromatic solutes in miscible, polar solvent/water mixtures was investigated through experiment and interpreted through chemical thermodynamic models. Eighteen solute/solvent/water systems were evaluated that represented different properties with respect to hydrogen bonding and functional group substitution. The presence of appreciable (i.e., percent by volume) organic solvent in the aqueous phase had a very large effect on the solubility of the more hydrophobic solutes. In general it was observed that there was a semi‐logarithmic increase in solubility with increasing solvent volume fraction. The increase in solute solubility with solvent volume fraction could be predicted by several chemical thermodynamic techniques, for which the accuracy improved with the extent of use of experimental data to account for nonideal effects. The results of this study are useful to understand solute physico‐chemical properties in heavily contaminated systems, such as in certain industrial wastewaters or in hazardous wastes containing polar solvents. Some of the findings from the investigation are employed in a companion paper to describe the effect of polar solvent on sorption of aromatic solutes onto soil.