Solvent extraction with volatile solvents was studied as a method for treating wastewaters from petroleum refineries and petrochemical plants. Extraction is most attractive when the loading of organics is high, when substances are present which pose difficulties for biological oxidation, and/or when the chemical value of recovered organics is high. Volatile solvents (isobutylene and isobutane) were given particular attention, since they are easily regenerated and since they have a low solubility in the effluent water. Equilibrium distribution coefficients were determined for numerous systems of water, various solvents and various solutes, and correlations of these coefficients were developed. A miniplant extraction facility was used to demonstrate the capabilities of extraction for treatment of seven different industrial wastewaters, and for the purpose of analyzing the underlying mass transfer and axial mixing behavior. The scale-up of the extraction system and the logic of selecting extraction processes for wastewater treatment are explored at length.

"Grant no. R801030." Prepared by the University of California, Dept, of Chemical Engineering, under the sponsorship of the Environmental Protection Agency. Includes bibliographical references (pages 277-284).