Advanced oxidation of acid yellow 11 dye; detoxification and degradation mechanism
Mohamed A. Hassaan, Ahmed El Nemr, Fedekar F. Madkour, Abubakr M. Idris, Tarek O. Said, Taher Sahlabji, Majed M. Alghamdi, Adel A. El–Zahhar
Abstract
Acid Yellow 11 (AY-11) is a toxicant azo dye discharged into the aquatic environment from textile, leather, food, and paper industries. This manuscript demonstrates the oxidation processes of AY-11 by ozone (O3) and ultraviolet (UV) assisted ozonation for decolorization and detoxification. Parameters affecting the performance of AY-11 decolorization process were optimized. The results revealed that the initial dye concentration and pH were effective parameters controlling the decolorization performance. More than 99% of decolorization was obtained within the first 20 min of the ozonation process at 100 µg/mL AY-11 dye and pH 9. The decolorization of AY-11 by O3/UV was slightly less efficient than the individual use of O3 in terms of chemical oxygen demand and color removal. Kinetics analysis indicated that AY-11 dye decolorization followed the pseudo-second order. The final degradation products of AY-11 dye in wastewater were identified using GC-MS. The AY-11 dye degradation intermediates were identified using LC-ESI-MS/MS. The toxicity test on the zooplankton of the treated aqueous solution indicated that the O3 and O3/UV treatments reduced the toxicity effect.