Fenton type processes for minimization of organic content in coloured wastewaters: Part I: Processes optimization

This study was focussed on the application of Fenton (Fe2+/H2O2) and Fenton “like” processes (Fe3+/H2O2 and Fe0/H2O2) for the minimization of organic content of coloured synthetic wastewaters. Two reactive dyes, C.I. Reactive Blue 49 with anthraquinone chromophore and C.I. Reactive Blue 137 with azo chromophore were used as model organic pollutants. Fenton type processes were investigated in order to establish optimal operating conditions (pH, concentration of iron salts or iron powder, and ratio of Fenton reagent) for the maximal degradation of investigated model coloured wastewaters. Degradation of studied dyes as organic pollutants was monitored on the basis of decolourization and mineralization extents of model solutions, determined by UV/vis spectrophotometric, and TOC and AOX analyses, respectively. Colour removal > 95% was achieved by all the applied processes, while mineralization extents ranged between 34 and 72% depending on the dye structure and applied AOP.