Plasma-catalytic Efficiency on the Discolouration of Sunset Yellow FCF in a Glidarc Plasma Reactor in Presence of WO₃ Used as Catalyst

In this work, we highlight the plasma-catalytic effect of gliding arc discharge on the bleaching of azo dye sunset yellow FCF in aqueous solution. The effect has been studied in the presence of tungsten oxide as a catalyst in the glidarc reactor. The catalyst has been synthesized via acid precipitation process. The product obtained was characterized by X-ray powder diffraction (XRD), Fourier Transform Infrared (FTIR) and Nitrogen Physisorption. The results showed firstly monoclinic structure of WO3 catalyst. The maximum bleaching rates obtained are 17% and 52.5% after 30 min for initial dye concentration of 25 mg.L-1 for plasma alone and plasma-catalyst, respectively. These results have clearly shown that gliding arc discharge has a double effect, in on hand as a source of hydroxyl radical and on other hands as a source of radiation able to excite the catalyst. The effects of initial pH and photocatalyst loading have been studied.