Influence of gaseous atmosphere on corona-induced degradation of aqueous phenol

The phenol degradation processes by pulsed corona discharges are investigated under three kinds of discharge atmosphere (air, argon and oxygen). The temporal variations of the concentrations of phenol and the intermediate products are monitored by LIF spectroscopy. The species of the intermediate products are identified by spectral analysis. It is clarified that the oxidative gaseous reagents produced from O2 and those from H2O degrade phenol to intermediate products with comparable degradation rates. The degradation via the reagents from H2O gives rise to the formation of molecules exhibiting fluorescence at 400-500 nm, in addition to dihydroxybenzene (DHB), while the degradation via the reagents from O2 produces only DHB. The reagents from O2 play an important role in the conversion of phenol to DHB