SOLUBILITY OF POLYCHLORINATED-BIPHENYLS IN BINARY WATER ORGANIC-SOLVENT SYSTEMS

Solubilities of four polychlorinated biphenyls (PCBs), 4-chlorobiphenyl, 2,4,6-trichlorobiphenyl, 2,3,4,5-tetrachlorobiphenyl and 2,2',4,4',6,6'-hexachlorobiphenyl, were determined in pure water and in several water/organic solvent (methanol, butanol, octanol, benzyl alcohol and benzene) systems using a generator column technique. A batch equilibrium method was also used to ensure that results from the two techniques were comparable. The presence of methanol and butanol in water enhanced the solubility of all four PCB congeners, the degree of the enhancement increasing with both cosolvent concentration and hydrophobicity of the PCB solutes. Dissolved octanol and benzene, at a concentration near saturation in water, reduced the solubility of the PCBs, with a larger reduction observed for the more hydrophobic PCB congeners. The effects of dissolved benzyl alcohol on the aqueous solubility of the four PCB congeners varied with the benzyl alcohol concentration and the individual PCB congener.