Ozone Degradation Of The Mechanism And Application Of The Dye

Along with the rapid development of industry, the amount of industrial waste water increase with years, the water environment problem is increasingly severe. Dyes effluents, a difficult point to treatment due to containing lots of non-degradation organic compound, had become one of the overriding pollutant source. Because of advantage of oxidation completed, efficient, non-secondary pollution, minimum the danger to humans, ozone oxidation technology has a broad potential. Providing theory supported and perfecting theoretical basis of ozone oxidation technology is where the aim of this paper.There direction had dicussed in this paper: reaction kinetics of ozone oxidation of dyes, the influence of three sizing materials to the process of ozone oxidation of dyes, the trends of toxicity of dyes during the process of ozone oxidation of dyes; then, some conclusions had been developed: (1) In the present study, the relationships between concentrations of water-soluble dyes solutions and reaction time were studied during the ozonation processes. It was found that the reaction kinetics orders are one with respect to both reaction time and dyes concentrations. After that the reaction rate constant equations are developed, of which the correlation coefficients (R²) are larger than 0.9600, then the apparent reaction rate constants (-k') and the half-life (t_1/2) for ozone degradation of textile dyes are calculated. And in all dyes, the smallest value of t_1/2 is 12.9s for Acid Scarlet B, while the largest value of t_1/2 is 86.6s for Weak Acid Grey ABL. Besides, other dyes' half-lives (t_1/2) are mostly at the range of 20-60s. (2) the influence of three sizing materials, PVA17-99, moditifed starch, KS-22, to the process of ozone oxidation of dyes in this paper, and the results showed that there is a trend of accelerated firstly, restrainted then of the rate of ozone degradation of textile dyes under the influence of the sizing materials in a some range; different sizing material have a different influence on different dye; for one dye, PVA17-99 can accelerate the rate of ozone degradation in a widest concentration range, moditifed starch takes second place, and KS-22 smallest; then, the possible reason of aforesaid had been explained on the basis of sizing material's structural formula and the way of ozone oxidation. (3) Fourteen dyes' toxicity trend in the process of ozone oxidation had been determined by Photobacterium phosphoreum, T3, and draw some conclusions: (1) there is a trend of increasing firstly and decreasing then of toxicity during the process of ozone oxidation. (2) the toxicity during the process of ozone oxidation of all dyes up to the maximizing, when the dyes' decolorizing rate reach 90%, be close to achromatic color; the probable reason of this is amount of aldehydes and amines had generated this moment, then, the toxicity can decrease when aldehydes and amines turned into organic acid by ozone; besides, it was found that acid Brilliant Blue G has a largest toxicity in the whole procee of ozone oxidation, this may be related with quantity of benzene rings, -SO₃Na, and the influence of non-bonding state proton.