Keywords: non–thermal plasma, humid air plasma, advanced oxidation, methyl orange, titanium dioxide, TiO2, hydrogen peroxide, plasma–chemical degradation, photocatalytic degradation, decolourisation, chemical reactions, azoic dyes, environmental pollution
Plasma–chemical and photo–catalytic degradation of methyl orange
Non–thermal atmospheric humid air plasma is used to investigate chemical reactions mechanisms of predominantly produced neutral hydroxyl radicals by gliding arc discharges with Methyl Orange (MO). UV/visible spectroscopy and electrochemical measurements were performed. Treated solutions show that highly reactive HO• radicals interaction favours the creation of intermediate species followed by their degradation leading to one aromatic ring end product. Photocatalytic (UV/TiO2 and UV/H2O2) treatments lead to the complete decolourisation of MO within few minutes. The results obtained may confirm that the final product of air plasma MO interaction contains NO2 and NH2 groups, the consequence of •NO presence in plasma.