Oxidation of textile dye reactive yellow 84 in aqueous solution in order to reuse treated water

Reactive Yellow 84 (RY84) is one of the most widely applied textile dyes because of its outstanding tinctorial properties. However, it has a very low affinity and it makes necessary to use large amounts of salt when RY84 is applied on cellulosic substrates. In this study, RY84 was treated by ozone in model solutions using a semi-batch bubbling reactor in order to recover water and salt for a further utilization in dyeing processes. Ozonation processes were carried out on solutions prepared at concentrations of dye as a typical dyehouse wastewater. In a first approach, it was analyzed the influence of initial dye concentration, initial temperature without further heating, and pH, on the ozonation. Additionally, with the scope to study the effect of chemical auxiliaries on ozonation process and on the result of reusing of treated water, model solutions simulating real effluents were prepared and ozonated. It was demonstrated that reusing of ozonated water is feasible, despite of the presence of ozonation byproducts and its accumulation during successive reusing cycles.