ADVANCED OXIDATION OF DISPERSE DYES IN AQUEOUS SOLUTIONS

摘要

Oxidation of two disperse dyes (Disperse Blue HGL and Disperse Red 60) in the aqueous solution was studied by ozone alone(O_3), Fenton's reagent(H_2O_2/ FeSO_4) and the combination of the two advanced oxidation methods(O_3 + H_2O_2/ FeSO_4), respectively in this paper. Ozonation was conducted by bubbling at room temperature at an ozone dose rate of 5.56 mg.min~(-1).l~(-1). It was found that ozonation was very effective to color removal and also COD and TOC removal as expected. Although TOC removal was different, better biodegradability was reached after ozonation for 75 minutes. It was also found that Fenton's reagent will be more effective at a ratio of FeSO_4 : H_2O_2 equals to 2:1 (mol: mol) and at an acidic pH. Study of the combination of the above two methods shows no stimulating results under the applied conditions. Liquid chromatograph of Disperse Red showed that ozone molecules first attack the surfactants and then both the surfactants and the dye itself.