酸度对染料臭氧化脱色效果及溶液毒性的影响

Influence of Acidity on Decolorization of Dyes by Ozonation and Toxicity of the Solutions

研究了20种染料溶液在臭氧氧化过程中吸光度的变化以及pH对氧化速率的影响,应用发光菌毒性检测法测定了活性翠兰KN-G,直接混纺大红D-GLN和酸性橙Ⅱ三种染料溶液在臭氧氧化过程中的急性毒性.结果表明:臭氧氧化20种染料的脱色过程符合一级反应动力学,其相关系数(R2)均大于0.950 0,反应溶液的初始pH对染料的脱色率有一定的影响.染料溶液初始浓度相同时,pH为2的酸性条件更有利于染料的降解,在前45 s,酸性溶液脱色率比中性溶液高出了6%～25%.在臭氧氧化染料溶液的过程中,溶液接近无色时,毒性较大,但随着氧化的进行其毒性逐渐降低.

Decolorization of 20 dyes with ozonation was investigated in the present study.Changes of absorbance of the solution and the effect of pH on degradation rate were examined.The acute toxicity of the solution of three dyes,Reactive Turquoise Blue KN-G,Direct Blending Scarlet D-GLN,and Acid Orange Ⅱ in the ozonation process was measured by the method of luminescent bacteria toxicity test method.The result showed that the ozonation decolorization process of 20 dyes solution was found to be a first-order kinetic reaction,of which the squared correlation coefficients（R2） were all larger than 0.9500.The initial pH of the solution had a certain influence on decolorization rate of dyes.With the same initial concentration,the decolorization rate of the acidic solution was higher than that of the neutral solution by 6%-25% during the first 45s of the ozonation,which indicated that the acidic condition at pH 2 maybe suitable for decolorization.Toxicity study suggested that maximum toxicity was exhibited at the stage of almost total color disappearance in the dye solution,while toxicity of the solution reduced gradually after further ozonation.