A continuous electrolytic treatment is being developed to remove emulsified oil from dilute oily wastewater streams, such as is generated in metal working operations. In this process, the wastewater permeates through an iron chip bed anode and steel mesh cathode. A potential is applied to the electrodes, forming ferrous ions at the anode and hydroxyl ions at the cathode. The ferrous ions react in a complex manner with the emulsifying agents, destabilizing the emulsion and generating an oil rich floating sludge and essentially oil-free water. A pilot plant unit capable of processing about 5700 l/day (1500 gal/day) was designed, constructed, and evaluated at an actual plant site. Operating parameters and process equipment were evaluated to assess the potential and problems of the process. Wastewater with initial oil concentrations in the range of 300 to 7,000 ppm of solvent extractables has been reduced to less than 50 ppm in 90% of the test runs, and to less than 25 ppm in 38%.

Prepared for U.S. Environmental Protection Agency, Office of Research and Development, Industrial Environmental Research Laboratory, Cincinnati, Ohio, submitted by Ford Motor Company, under grant no. S-807174. Includes bibliographical references (page 48).