Oxidation of gaseous elemental mercury in a high voltage discharge reactor

Effects of the voltage waveform, discharge tooth wheel number and CO2/NO/SO2 concentration in the simulated flue gas on Hg-0 oxidation were investigated using a link tooth wheel-cylinder reactor energized by different high voltage power supplies. Negative DC discharge induced more ozone production and a higher Hg-0 oxidation efficiency than positive DC discharge and 12 kHz AC discharge. The discharge tooth wheel number had almost no effect on the maximum Hg-0 oxidation efficiency. The allowable supplied voltage decreased with the increase of discharge tooth wheel number. CO2 could stabilize the discharge process and increase the maximum voltage for a stable discharge. It has also been found that NO consumed O-3 induced by high voltage discharge, thereby decreased Hg-0 oxidation efficiency; while SO2 had a slight promoting effect on Hg-0 oxidation.