Silva Alessandra C, Pic Jean Stephane, Sant'Anna Geraldo L, Dezotti Marcia
Chemical Engineering Program, COPPE, Federal University of Rio de Janeiro, CEP 21941-972 Rio de Janeiro, Brazil.
J Hazard Mater. 2009 Sep 30;169(1-3):965-71. doi: 10.1016/j.jhazmat.2009.04.051. Epub 2009 Apr 19.
Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L(-1), NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation.
在一个8.5升的监测型实验室规模鼓泡塔反应器中，研究了两种偶氮染料在不同液体介质盐含量（0、1、40和100克/升，氯化钠）下的臭氧化过程。在橙黄II的实验中，pH值有所变化（5、7.5和9），但酸性红27的臭氧化过程是在pH值为7.5的条件下进行的。臭氧自分解速率常数随盐浓度的增加而增大。在所有实验条件下，脱色效果非常显著且能快速实现。对于所测试的两种偶氮染料，在30分钟的臭氧化试验中，超过98%的颜色强度被去除。然而，在这类实验中，偶氮染料仅实现了部分矿化（橙黄II为45%；酸性红27为20%）。矿化程度（总有机碳去除率）受到盐浓度的负面影响。通过呼吸测定法进行的生物降解试验揭示了臭氧化过程中形成的染料降解产物的抑制作用。
