Pulsed discharge purification of water containing nondegradable hazardous substances

Abstract

AbstractWe investigate the decomposition characteristics of phenol in an aqueous solution under exposure to pulsed discharge plasma. The investigation is carried out with different electrode configurations, applied voltages, and humidity levels and compositions of the background gas. It is possible that in the case of all gases, OH radicals are responsible for the decomposition of phenol in the solution. In pure O2, the decomposition rate of phenol increases due to the generation of O and O3. In pure N2, OH radicals produced by N2, which is excited in the metastable state, contribute to phenol decomposition. In N2‐O2, the decomposition rate of phenol remains low, and the NOx produced by the pulsed plasma in a N2‐O2 mixture destroys O3, and the production of the NOx inhibits O3 production. In Ar‐O2, the decomposition rate of phenol increases with an increase in the concentration of Ar in the mixture. It is possible that excited Ar atoms are responsible for the decomposition of phenol in the solution at higher concentrations of Ar in Ar‐O2. Further, it is found that the decomposition rate of phenol in aqueous solution exposed to a pulsed discharge is almost the same as that of phenol in aqueous solution exposed to a DC corona discharge. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(2): 1–8, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.20937