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 >> pCBA. 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 x 10(5) J/L) was supposed to react strongly with NO(2)A degrees radicals produced by the dissociation of N2O4 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 pCBA, oxidation occurs in the liquid solution, but the degradation is low because of its low reactivity with species such as ozone and A degrees NO2 and insufficient production of OHA degrees radicals in the solution.