Bubble Interface Behaviors and Degradation Characteristics in an Underwater Pulsed Capillary Discharge

Abstract

Capillary discharge has been paid attention as one of the effective methods to decompose persistent organic pollutants (POPs). Applying voltage to a capillary filled with liquid generates bubbles due to Joule heating. Then, OH radicals are generated by discharge in the bubble. Conventionally, DC power supply has been used for the capillary discharge. Since input energy is also spent for the bubble generation in the DC capillary discharge, the energy efficiency can be improved by biased DC pulsed applied voltage. In this study, decolorization of methylene-blue solution by DC biased pulsed capillary discharge was conducted to clarify the decomposition characteristics of persistent organic pollutants. Moreover, the correlation between decomposition and discharge was discussed through the analysis of bubble dynamics by high speed visualization measurement.