Abstract: Chlorine dioxide has strong property of oxidation, the instability and the disinfection, its oxidized ability is more than 9 time of hypochlorous, and is 2.6 times of chlorine. This article is based on the production and the preparation of chlorine dioxide and stable chlorine dioxide, the content of the acid red was after reaction determined by Spectrophotometric methods, thus decolorization rate of acid red was calculated with chlorine dioxide. Then the decolorization effect of the acid red by reaction temperature, pH, mixing speed, the amount of chlorine dioxide, concentration of acid red, reaction time were studied. The experimental result indicated that, the decolorization rate can achieve above 95% by chlorine dioxide under the certain condition. The reaction temperature, the mixing speed, and concentration of the acid red have no evident influence to the decolorization rate. The reaction is very quick. The reaction would be completed within 5 minutes, so it has no influence to decolorization rate under acidic condition, but under the alkalinity condition, the larger pH is , the lower decolorization rate is. So the best condition were the followings: reaction temperature is 25℃, reaction time is 10min, rotational speed is 250r/min, pH is 6, the ratio of the acid red and a chlorine dioxide is 1: 3.
