Environmental considerations dictated the necessity of reducing the phenol content of a waste water to less than 1 PPM. Tests were conducted in a 2 inch diameter column and the test column was optimized with respect to plate spacing and volumetric efficiency. The production unit, scaled up from the test unit, was 5 ft. in diameter. Waste water levels of 0.1 to 0.2 ppm phenol in the raffinate were obtained for feed flows ranging from 150 to 350 gpm and phenol contents in the feed from 400 to 1100 ppm. The empirical scaleup procedure was verified.