Oxidation of gaseous elemental mercury in a high voltage discharge reactor

Abstract

Effects of the voltage waveform, discharge tooth wheel number and CO2/NO/SO2 concentration in the simulated flue gas on Hg0 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 Hg0 oxidation eficiency than positive DC discharge and 12 kHz AC discharge. The discharge tooth wheel number had almost no effect on the maximum Hg0 oxidation eficiency. 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 O3 induced by high voltage discharge, thereby decreased Hg0 oxidation eficiency; while SO2 had a slight promoting effect on Hg0 oxidation. © 2009 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.