A 500 pF capacitance was positioned between the outer electrode and the connection to measure the input energy according to the Manley method [25].Dielectric barrier discharge applied voltage (Ua) and high capacitance voltage (Um) are measured by LeCroy high voltage probes and recorded by a digital oscilloscope (LeCroy LT342, 500 MHz). Manley’s method was used to collect the charges transferred throughthe reactor [21, 25]. The Lissajous plot method was used to determine the plasma-injected energy by cycle and then to calculate the power input injected in the reactor as well as the specific energy (Espe) [25]. The specific energy was fixed at Espe = 14 J L-1 (P = 0.95 W) for all experiments. This rather low value of specific energy avoids a noticeable formation of NOx which remains in the ppb range.