Ozonation of Secondary Effluent for Color Removal

The purpose of this study was to determine the effect of various ozone concentrations when applied to secondary kraft effluent in regards to color removal. The influence of effluent temperature upon the color removal capabilities of ozone was also investigated to determine the optimal ozone reaction temperature or the temperature which would result in the greatest color reduction at a given ozone concentration. The study was conducted by injecting ozone at three different concentrations of 20, 30 and 40 mg/liter into a temperature controlled column of secondary kraft effluent obtained from S.D. Warren Company in Muskegon, Michigan. The temperature was adjusted to maintain levels of 70, 80, and 90°F (±2°F). This resulted in nine separate runs of various ozone concentrations and temperature combinations. These runs were evaluated in terms of spectroscopic adsorption using the Perkin-Elmer UV-VIS spectrophotometer. This study indicated that increasing levels of ozone addition cause greater color removal, but at a decreasing rate. In every case, the greatest color removal was obtained with an addition of 40 mg/liter. Also, effluent temperature had an effect on the color removal efficiency of ozone. The maximum efficiency was obtained at a temperature of 80°F