Electro-catalytic oxidation of phenacetin with a three-dimensional reactor: Degradation pathway and removal mechanism

Phenacetin is a common analgesic, anti-arthritic and anti-rheumatic drug. This study dealt with the degradation of phenacetin in alkaline media using a three-dimensional reactor with particle electrodes. Particular attention was paid to the degradation pathway and the reaction mechanism in the system. Liquid chromatography coupled with time-of-flight mass spectrometry was used to identify the intermediates. The phenacetin was observed to be firstly cut off the branch chains main by direct oxidation, and then the intermediates further degraded to ring opening products by hydroxyl radical resulting from indirect oxidation and finally mineralized to CO2, H2O. A possible removal mechanism was proposed that direct and indirect oxidation together did effect on the pollutants with oxygen. [Display omitted] •Intermediates and pathway of phenacetin by three-dimensional electro-catalytic reactor were identified.•Phenacetin is firstly cut off branch chains, and the intermediates then generates ring opening products.•Direct oxidation combine with indirect oxidation remove phenacetin in the three-dimensional electro-catalytic reactor.•O2 participates in the indirect oxidation process and has a good effect on the reaction.