Water Treatment Using Discharge on the Surface of a Bubble in Water

Abstract

Summary: A new method for water treatment utilizing radicals produced by a discharge on the surface of a bubble in water is proposed and this method is applied to the de‐color of indigo solution whose original color is blue. The discharge of this method begins at the crossing points of mesh electrode, acrylic resin spacer, and bubbling gas (i.e., called a triple junction where there is a weak point for the electrical breakdown in the electrical power devices). This weak point for the electrical breakdown is used very actively for the surface discharge. The discharge process on the surface of the bubble in water is also observed using a wire‐to‐plane electrode system to fix the observation region of discharge (type‐A reactor). The streamer length estimated by photographs increased linearly with the applied voltage. The energy consumption of discharge for type‐B reactor with a mesh‐to‐plane electrode in oxygen is about 0.09 J when the applied voltage is 20 kV. Production efficiency of the H2O2 concentration of about 27 mg · L−1 in oxygen (46 mg · L−1 in helium) has been obtained when the repetition rate of discharge operated by a pulsed‐power generator, the peak value of applied voltage, and the discharge period are 100 pps (pulsed power generator), 25 kV and 60 min, respectively.

Two-Dimensional Concentration Distribution of Hydrogen Peroxide Generated by Atmospheric-Pressure Plasma Jet Irradiation

“…We reported that H 2 O 2 was generated in the distilled water irradiated with the plasma jet and that the H 2 O 2 concentration increased with irradiation time according to results of flow injection analysis * Corresponding author: kuwahata@keyaki.cc.u-tokai.ac.jp (FIA) [19]. Some reports show that, similar to our results, the generation of H 2 O 2 in water was induced by on-water discharge [20,21] and on-water irradiation of atmospheric-pressure plasma [22,23].…”

Structure of positive streamers inside gaseous bubbles immersed in liquids

“…Bruggeman showed 1 Author to whom any correspondence should be addressed. that streamers preferably take paths along the surface of the bubble when the bubble is immersed in a high dielectric constant liquid such as water [4,5].…”

“…Electric discharges in liquids, and streamers in particular, are being intensively investigated due to their wide-ranging applications, from removal of volatile organic compounds (VOCs) from water to surgical instruments [1][2][3][4][5]. In most cases, streamers do not propagate directly through the liquid phase.…”

Plasma Technology: A New Remediation for Water Purification with or without Nanoparticles

“…Th e discharge of this method has been thought to begin at the crossing points of mesh electrode, acrylic resin spacer, and bubbling gas (i.e., called a triple junction, where there is a weak point for the electrical breakdown in the electrical power devices). Th is weak point for the electrical breakdown has been very actively used for the surface discharge [46].…”