Research Unit of Textile and Paper Materials, Rua Marquês d'Avila e Bolama, 6201-001 Covilhã, Portugal.
J Hazard Mater. 2010 Jun 15;178(1-3):57-65. doi: 10.1016/j.jhazmat.2010.01.043. Epub 2010 Jan 18.
To study the fast kinetic decolourisation of textile dyes by ozone a continuous quench-flow system was used. This system has not been used before for these purposes. Reaction times in the range of 7-3000 ms were explored. The reaction was quenched with potassium iodide, which proved to be very effective, and the indigo method was used to follow the ozone concentration. Dyes from the most representative chemical classes currently used in the textile industry, i.e. azo and anthraquinone, were selected. Using the initial slope method, the effect of dye and ozone concentrations was researched and the kinetic equations thus established. Using tert-butyl alcohol, as radical scavenger, and pH close to 2.5, the second-order rate constant of the reactant dyes at 280 K varies in the range of 1.20x10(4)-7.09x10(5)M(-1)s(-1); the Acid Orange 7 exhibiting thus its lowest value, the Acid Blue 45 its highest value and the Acid Green 25 and 27 and Direct Yellow 4 intermediate values (approximately 1.6x10(5)M(-1)s(-1)). Without radical scavenger and the pH close to 4, the reaction rate increases one order of magnitude, but, on the reverse, the efficiency of ozone to decolourisation decreases.
为了研究臭氧对纺织染料的快速动力学脱色作用，采用了连续淬灭流动系统。该系统以前未用于此类目的。探索了 7-3000ms 范围内的反应时间。反应被碘化钾猝灭，这被证明是非常有效的，并且使用靛蓝法来跟踪臭氧浓度。选择了目前在纺织工业中使用的最具代表性的化学类别的染料，即偶氮染料和蒽醌染料。使用初始斜率法，研究了染料和臭氧浓度的影响，并建立了相应的动力学方程。使用叔丁醇作为自由基清除剂，并将 pH 值接近 2.5，在 280K 时反应物染料的二级反应速率常数在 1.20x10(4)-7.09x10(5)M(-1)s(-1)范围内变化；酸性橙 7 表现出最低值，酸性蓝 45 表现出最高值，酸性绿 25 和 27 以及直接黄 4 表现出中间值（约 1.6x10(5)M(-1)s(-1)）。没有自由基清除剂且 pH 值接近 4 时，反应速率增加了一个数量级，但另一方面，臭氧对脱色的效率降低。
