Removal of Model Pollutants in Aqueous Solution by Gliding Arc Discharge: Determination of Removal Mechanisms. Part I: Experimental Study

• Published in: Plasma chemistry and plasma processing 2013-02, Vol.33 (1), p.97-113
• Main Authors: Iya-Sou, D., Laminsi, S., Cavadias, S., Ognier, S.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Classical Mechanics; Inorganic Chemistry; Mechanical Engineering; Original Paper
• ISSN: 0272-4324; 1572-8986
• DOI: 10.1007/s11090-012-9423-7

The respective roles of short and long-life oxidant species in the degradation of model organic pollutants in water have been investigated in a gas–liquid gliding arc plasma reactor. Three different model pollutants were treated in two configurations: direct discharge mode and spatial post discharge mode. In each case the pollutants were classified according to their ease of removal, from easier to more difficult to remove. The results were as follows: phenol >> 1-heptanol >>  p CBA. The removal mechanisms also are different depending on the characteristics of the pollutant treated. Phenol (100 % of phenol was removed for energy density = 1.20 × 10 5  J/L) was supposed to react strongly with NO 2 ° radicals produced by the dissociation of N 2 O 4 in liquid phase. The degradation of 1-heptanol would proceed by desorption of the liquid phase to the gas phase, where oxidation occurs due to the plasma active short-lived species. In the case of p CBA, oxidation occurs in the liquid solution, but the degradation is low because of its low reactivity with species such as ozone and °NO 2 and insufficient production of OH° radicals in the solution.