Reaction kinetics of spent reactive dye bath ozonation process

Oxidation of a spent reactive dye bath containing a mixture of Remazol brand dyes as well as two main inorganic additives was carried out using ozone and decolorization was obtained in a relatively short time (10-30 min) and ozone utilizations were between 329 and 1609 mg. The spent dye bath oxidation could not be represented by any simple kinetics. Ozonation kinetics and decolorization character was evaluated using synthetic samples with dyes and assisting chemicals. Synthetic Dye Sample decolorization was achieved in 90 s with ozone utilization of 32 mg. NaCl addition decelerated the decolorization rate and increase the ozone utilizations. Na₂CO₃ addition resulted in high pH and alkalinity and changed the mechanismof ozonation process as well as decolorization reactions yielding a better oxidation than that of the sample containing only NaCl.