Decomposition of Trace Phenol in Solution Using Gas–Liquid Interface Discharge

Abstract

Many researchers have investigated the decomposition of trace phenol in solution using liquid-phase discharge. However, liquid-phase discharge has a problem of consuming an extremely high energy. We have investigated phenol decomposition using a gas–liquid interface discharge induced by an ultra-short width (∼600 ns) pulse of high voltage. Gas bubbling was employed to enhance both convection and the gas–liquid interface area, because chemical reactions take place mainly at the surface of a solution. A significant improvement in energy efficiency of phenol decomposition was achieved. In addition, phenol decomposition using air mixed with argon (Ar) and hydrogen peroxide (H2O2) as a bubbling gas was investigated. Phenol removal using air together with H2O2 bubbling was approximately twice as efficient as air bubbling alone, which was attributed to the increase in the amount of hydroxyl (OH) radicals.

Decomposition of tetrodotoxin using multi-gas plasma jet

“…And these active gas species react with water to produce OH radical, singlet oxygen and other active species. Among these species, it is thought that the OH radical has the potential to oxidize organics to carbon dioxide and water (Kuroki et al, 2006). Therefore, oxygen and nitrogen plasma were selected as high OH radical production plasma gas species , and TTX solution were treated.…”

Generation of Nitric Acid and Nitrous Acid in Distilled Water Irradiated with Atmospheric-Pressure Plasma Jet

“…Electrons ( 3 were generated in air by atmospheric discharge [15]. Miyazaki et al found, using a gas detector, that O 3 , NO, and NO 2 were generated in a N 2 -O 2 gas mixture upon pulse discharge [4].…”

“…For example, researchers have reported the decomposition of phenol [1][2][3], organic dyes [4,5], and acetic acid (as a model of persistent organic substances) [6] in water using on-water pulse discharge and the decomposition of organic dyes [7,8] in water using on-water atmospheric-pressure plasma.…”

“…In that study, we carried out measurements by absorption spectroscopy and capillary electrophoresis and reported that (1) nitric acid (HNO 3 ) was generated in distilled water irradiated with an Ar plasma jet, (2) the generated nitrate ions (NO 3 − ) contributed to a peak at a wavelength of approximately 200 nm in the absorbance spectrum, and (3) the NO 3 − concentration increased with the plasma irradiation time [10]. However, the estimated NO 3 − concentrations were not reported.…”

Identification of Peak near 200 nm in Absorbance Spectrum of Distilled Water upon Atmospheric-Pressure Plasma Jet Irradiation

“…Research is ongoing on water purification by the decomposition of harmful organic compounds in water using discharges and plasmas, such as underwater pulsed streamer corona discharge [1,2], underwater RF plasma within bubbles [3,4], atmospheric-pressure pulse discharges on water [5,6], and atmospheric-pressure plasma on water [7,8]. Previously, we directly irradiated a plasma jet, which can be released into the atmosphere using our device [9], onto an aqueous solution containing methylene blue, a blue dye used as a model organic substance, and reported the resulting decolorization of the methylene blue aqueous solution [10].…”