Effect of structure of corona-discharge reactor on removal of dilute gaseous pollutants using selective electron attachment

Low-energy electrons generated in a corona-discharge reactor are captured by electronegative impurities, producing negative ions. The ions migrate in the electric field to the anode (reactor wall) and are removed at the wall. The effects of the reactor structure, namely, the cathode diameter, the anode (reactor) shape and the number of cathodes on the removal efficiency with respect to three dilute gaseous pollutants, methyl iodide, chlorofluorocarbon and acetaldehyde, are investigated experimentally. The results reveal that the thicker the cathode diameter, the higher the removal efficiency. In contrast, the smaller the reactor diameter among three equivolume reactors, the higher the removal efficiency, As for the number of cathodes in a single reactor vessel, the single-cathode reactor exhibits higher removal efficiency than the 5-cathode one.