Initiation of Fenton process by plasma gliding arc discharge for the degradation of paracetamol in water

Abstract

This study aims to initiate the Fenton process by non-thermal plasma generated by Gliding Arc Discharge (GAD) to degrade completely Paracetamol (PCM) in water. PCM is a representative of emerging pollutants of pharmaceutical origin. The degradation and the mineralization of the molecule were investigated using HPLC and TOC analytical techniques. The treatments were applied separately then coupled to evaluate the synergy between the two processes: (i) the Fenton process has caused a complete degradation but low mineralization in the order of 34% was obtained; (ii) the GAD process applied with short electrical discharge shows 15.8% degradation in 30 sec, while the mineralization reached 20.1%; (iii) in postdischarge mode, the previous percentages increased to 62.6 and 49.6% for degradation and mineralization, respectively. The HPLC technique indicated the persistence of some by-products for the three cases of single water treatments.The plasma initiation of the Fenton process gave a high degree of mineralization (>92%) and a complete removal of the aromatic intermediates in postdischarge mode. This plasma initiation allowed the excitation (plasma-sensitization) of PCM molecules witch improved the Fenton process. Based on the results of this study, oxidation pathway of paracetamol has been proposed.