Removal of SO2 using a wet-type nonthermal plasma reactor

Wet-plasma process for SO/sub 2/ removal has been proposed, and fundamental characteristics have been evaluated. The plasma reactor was a wire-cylinder wet type ESP that was driven by pulsed high voltage. Water film containing ammonium peroxodisulfate ((NH/sub 4/)/sub 2/S/sub 2/O/sub 8/) was maintained on the wall of the reactor. By raising the temperature of the solution up to 80/spl deg/C, ammonium ion (NH/sub 4//sup +/) and hydrogen peroxide (H/sub 2/O/sub 2/) were generated in the solution. The former enhances SO/sub 2/ absorption into the solution and the latter is effective to oxidize S species. The experiment was carried out at 40/spl deg/C and 80/spl deg/C of the solution, and with three initial concentrations of ammonium peroxodisulfate (0%, 5%, 10%). SO/sub 2/ removal rate increased with increasing the initial concentration of ammonium peroxodisulfate. Higher temperature of the solution yielded higher SO/sub 2/ removal rate. SO/sub 2/ removal rate more than 95% was observed at the optimum condition. In this experiment (80/spl deg/C, (NH/sub 4/)/sub 2/S/sub 2/O/sub 8/:10%) with the specific input energy of 22 kJ/Nm/sup 3/ with NH/sub 4//sup +/ ion, SO/sub 2/ absorption was enhanced significantly even the pH value of the liquid became lower than 3.