染料溶液的臭氧脱色效率和残留物的分析研究

RESEARCH ON THE DECOLORIZATION EFFICIENCY BY OZONE AND RESIDUES OF DYE AQUEOUS SOLUTION

选用偶氮、蒽醌和菁型三类染料中的11种作为研究对象,考察不同反应时间下臭氧对染料色度脱除和溶液pH值变化的影响,并对降解后溶液中的残留物进行定量分析.结果表明,除分散染料外,所有可溶性染料在20m in内的脱色率均达到79%以上;不同应用类型染料的脱色速率顺序为:活性>酸性>直接>阳离子>分散,在可溶性染料中,同类型的分子质量小的染料脱色速率较快.酸性物质的生成使得溶液的pH值随反应时间的推移而下降,最终pH值都低于4.5,pH值与脱色率在总体上的变化趋势一致.臭氧氧化脱色表现为复杂的染料分子被降解成为简单的有机化合物,染料分子中的—SO3H和—C l基团大部分生成了SO24-和C l-,而PO34-仍以游离的H2PO-4存在于溶液中,氮则是根据其基团的不同而部分被降解生成NO-3,降解溶液中不存在NO-2.

This experiment had selected 11 kinds of azo, anthraquinone and lush dyes in order to investigate the decolorization of dyes by ozone in the condition of different reaction time and pH value, and the residues in the degrading solution. The results indicated that except of disperse dyes, the decolorization efficiency of all soluble dyes reached over 79% in 20min. , The sequence of the decolorization reaction rate is ： reactive 〉 acid 〉 direct 〉 cationic 〉 disperse. In the same type of soluble dyes, the decolorization rate of small molecular mass is quicker. The results also showed that some acid materials could be produced, causing the decrease of pH value with increasing the reaction time, and the final pH values were less than 4. 5, the trend of the pH change was consistence with the decoloziration efficiency. The decolouring to ozone oxidize was shown as the complicated dye molecules were degraded to the simple organic compounds, -SO3H, -Cl in the dye molecules were generated into SO4^2-, Cl^-, and PO4^2-existed with dissociated H2 PO4. Nitrogen were partially degraded to NO3 on the basis of different groups and NO2^- did not exist in the degrading solution.