Environmental applications of electric discharges are being considered increasingly more often: they imply the chemical properties of the activated species generated in and by the discharge. An overview of the resulting chemical effects is presented, based on rationalized classification, i.e., acid-base effects, oxidizing properties, complex forming reactions, and radical reactions. The gliding discharge is considered to be a specifically suitable plasma source for the treatment of liquids for pollutant abatement in the scope of sustainable environment, and this justifies an overview of the chemical properties. Special emphasis is devoted to temporal post-discharge reactions (TPDRs), which occur when the target is no longer exposed to the plasma source, and several typical examples are detailed. These recently evidenced TPDRs seem to present some general character. They are the key parameters to estimating the efficiency of a discharge treatment; they also have major technical and economical importance for the application of the plasma treatment to pollutant and/or micro-organism abatement at atmospheric pressure and quasi-ambient temperature.

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.