An apparatus for electrophoretically removing contaminants from an oil-based drilling fluid includes a housing, a drum, a means for rotating the drum, and a scraper head. The drum is retained within the housing above the housing floor. The oil-based drilling fluid is directed along the housing floor, contacting both the housing floor and the drum. A negative charge is applied to the drum and a positive charge is applied to the housing, creating an electrical field through the fluid. Drilling fluid contaminants are attracted to and collect upon the drum outer surface. The means for rotating the drum turns the drum through the fluid and collected contaminants remain on the drum outer surface. The scraper removes the collected contaminants from the drum outer surface as it rotates. A method for removing contaminants from an oil-based drilling fluid includes directing the contaminated into the electrically charged housing, adjusting the drum height of the oppositely electrically charged drum so that it contacts the fluid, rotating the drum to remove the contaminants collected thereon from the fluid, and scraping the drum with a nonconductive scraper head to remove the contaminants.