Degradation of indigo carmine in water induced by non-thermal plasma, ozone and hydrogen peroxide: A comparative study and by-product identification.

The non-thermal plasma (NTP) technique is an advanced oxidation technology (AOT) applied to the degradation of organic compounds in water. In this study, the degradation kinetics of indigo carmine was investigated systematically, applying N-NTP, O-NTP, ozonolysis and hydrogen peroxide and the results were compared. The transient species (OH, O and NO radicals) formed with the NTP discharge at the gas-liquid interface and their products (NO, NO, HO) stabilized by the water, were identified and quantified.