Oxidation of aqueous p-Nitroaniline by pulsed corona discharge

Toxic and potentially carcinogenic aromatic amines widely used in industry find their way to the aquatic environment. Gas-phase pulsed corona discharge (PCD) treatment of recalcitrant organic pollutants is a promising energy-efficient advanced oxidation process. The study assessed the energy efficiency of PCD in oxidation of p-nitroaniline (PNA), a persistent and ubiquitous pollutant of the aquatic environment. The effect of process control parameters on the energy efficiency of PNA degradation was studied including pH, gas–liquid contact surface and applied pulse repetition frequency. The results showed that PCD surpasses the commercially available competitor, Fenton reagent, for about three times. The reaction intermediates were analysed by HPLC-MS(ESI ± ) resulting in proposal of two transformation products. The PNA oxidation process followed the second-order kinetics showing the reaction rate coefficient moderately increasing with the contact surface and decreasing with the pulse repetition frequency. The acute toxicity of PNA solutions decreased substantially on the course of PCD treatment.