Abstract:
In the present study, Fenton and sono-Fenton processes were applied to the oxidative decolorisation of
synthetic textile wastewater including CI Reactive Orange 127 and polyvinyl alcohol. Process optimisation
[pH, ferrous ion (Fe2+) and hydrogen peroxide (H2O2)], kinetic studies and their comparison were
carried out for both of the processes. The sono-Fenton process was performed by indirect sonication in
an ultrasonic water bath, which was operated at a fixed 35-kHz frequency and 80 W power. The
optimum conditions were determined as [Fe2+] = 20 mg l)1, [H2O2] = 15 mg l)1 and pH = 3 for the
Fenton process and [Fe2+] = 25 mg l)1, [H2O2] = 5 mg l)1 and pH = 3 for the sono-Fenton process.
The colour removals were 89.9% and 91.8% by the Fenton and sono-Fenton processes, respectively.
The highest decolorisation was achieved by the sono-Fenton process because of the production of
some oxidising agents as a result of sonication. Consequently, ultrasonic irradiation in the sono-Fenton
process slightly increased the colour removal to 91.8%, while decreasing the hydrogen peroxide dosage
to one-third of that of the Fenton process.