Polarity effect of pulsed corona discharge for the oxidation of gaseous elemental mercury

The effect of polarity on the oxidation of Hg0 was examined in the presence of O2 via a pulsed corona discharge (PCD). The experimental result showed no difference in the energy yield of Hg0 oxidation at both positive and negative PCDs (∼8 μg Hg W h−1 at following conditions: total flow rate = 2 L min−1 (Hg0 = 50 μg N m−3, O2 = 10%, and N2 balance), temperature = 150 °C, and specific energy density = 5–15 W h N m−3). This suggests that the positive PCD process used to control gaseous air pollutants may play an essential key role in Hg0 oxidation because it consumes enough energy (∼15 W h N m−3) but an electrical precipitator could not because it consumes less energy (∼0.3 W h N m−3) to oxidize Hg0.

► Polarity effect of a pulsed corona discharge (PCD) for Hg0 oxidation. ► No difference in the energy yield of Hg0 oxidation at both polarities. ► Positive PCD process playing essential key role in Hg0 oxidation. ► Electrical precipitator (EP) consuming less energy than positive PCD. ► EP not playing essential key role in Hg0 oxidation.