[Effects of gas compositions on the oxidation of gas phase elementary mercury by non-thermal plasma].

The effects of flue gas compositions such as NO,SO_2,CO,H_2O on elementary mercury oxidation by non-thermal plasma induced by positive streamer discharge were experimentally investigated by using a link tooth wheel-cylinder reactor.The results showed that the oxidation of elementary mercury decreased in the presence of CO_2 and NO,which was attributed to the reduction of number of the active radicals reacted with elementary mercury.Adding(670 mg/m~3) NO,only 37% elementary mercury was oxidized when the voltage was 9.5 kV.And CO was produced because of the reaction between CO_2 and active radicals.The presence of SO_2 resulted in an increase of elementary mercury oxidation,and white HgSO_4 and Hg_2SO_4 were formed,little elementary mercury was detected at the outlet of the reactor when the voltage was 10 kV.Similarly,H_2O and HCl promoted the oxidation of elementary mercury,which may be due to the formation of oxidative ·OH and the presence of Cl~-ions.The total mercury concentration dramatically decreased after the discharge reactor because the charging mercury was collected.