The effect of trichloroethene on the aqueous solubility of chlorobenzenes

Abstract

Cosolute effects of trichloroethene (TCE) on the solubility of seven chlorobenzenes have been studied. The chlorobenzenes chosen for the study were mono-, di- and trichlorobenzenes. The solubilities of these chlorobenzenes were determined with and without the presence of TCE. TCE concentrations used ranged from O to 3300 ppm (above solubility). It has been found that reliable measurements demand relatively long mixing times and settling times to minimize the effect of colloids. Experimental results indicate that (1) most published solubility data for chlorobenzenes are apparent solubilities (i.e., a function of experimental procedures); (2) the solubilities of chlorobenzenes which are liquid at 25 °C decrease with increasing concentrations of TCE; and (3) TCE does not decrease solubilities of chlorobenzenes which are solid at 25 °C unless TCE present in the organic phase dissolves the solid chlorobenzene. The model used to predict the co-solute effects on aqueous solubilities indicates that near ideal behavior 1s observed. These results suggest that chlorobenzene concentrations below solubility do not necessarily indicate the absence of an organic phase.