Enhanced Degradation of Phenol by Carbonate Ions With Dielectric Barrier Discharge

The influence of carbonate ions on plasma degradation of phenol in water treated by dielectric barrier discharge was tested. The plasma degradation pathway of phenol was also investigated through detecting the main degradation products by HPLC and HPLC/MS. Our results indicate that the degradation efficiency of phenol is significantly intensified in the presence of carbonate ions, particularly at lower phenol concentration, and is gradually increased with increasing carbonate concentration up to a maximum at 1.2 g · L^-1. As a consequence of this process, carbonate radicals are generated from the scavenging of the hydroxyl radical by carbonate ions and are highly reactive to electron-rich compounds such as phenol. Moreover, the results clearly demonstrate that the plasma degradation pathway of phenol is dominated by a carbonate radical derived from the reaction of phenoxyl radical and peroxyl radical.