Density and Rotational Temperature Measurements of the OH° and NO° Radicals Produced by a Gliding Arc in Humid Air

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Plasma treatment of aqueous solutes: Some chemical properties of a gliding arc in humid air

The chemical properties of the gaseous species generated in a humid air gliding arc discharge are investigated. Aqueous solutions are used as the targets exposed to the plasma, and this allows to evidence strong acid and oxidizing effects on various solutes by means of spectrometric or potentiometric methods. The influence of some working parameters such as the input gas flow, the distance from the electrodes to the target or the electrode gap is examined on the chemical transform and simple experimental laws are derived. A general feature is observed for oxidation and suggests the occurrence of an auto-catalytic step in the relevant kinetic mechanism

Acidity control of the gliding arc treatments of aqueous solutions: application to pollutant abatement and biodecontamination

A tight control of acidity is needed for performing oxidation–reduction reactions of organic compounds dissolved in liquid media, since the relevant reactions often involve the occurrence of protons; the matching kinetics are therefore acidity dependent. This feature holds for plasma treatments of aqueous wastes which are intended to abate the concentration in organic pollutants. Exposure of aqueous solutions to a gliding arc plasma in humid air induces acid and oxidising reactions in the condensed phase. Acid effect results from the occurrence of NO species formed in the plasma and leads to the formation in water of nitrous and nitric acids, which are responsible for a steep pH fall. Using selected buffers allows accurate controlling of the acidity, which is necessary for most of the plasma-chemical or plasma-biochemical reactions