Integrated strategy for efficient simultaneous desulfurization and denitrification of flue gas and high value conversion of sulfur and nitrogen resources

Nitrogen and sulfur oxides have been considered as major air pollutants , which has raised concerns. In this study, an integrated strategy is proposed for simultaneous desulfurization and denitrification of simulated flue gas and high value conversion of sulfur and nitrogen resources. The high oxidation capacity of the thermal-electric coactivated (NH 4 ) 2 S 2 O 8 made the process highly effective for SO 2 and NO removal, with efficiencies of 100 % and 98 %, respectively. Mechanistic studies have revealed that highly reactive free radicals were the major participants in promoting oxidation, among which 47.65 % and 27.75 % of NO were oxidized by SO 4 .- and ˙OH, respectively, and 14.3 % and 10.3 % removal were accounted for O 2 .- and 1 O 2 , respectively. The products of desulfurization and denitrification (SO 4 2- and NO 3 - ) were further converted into NH 4 + (maximum conversion efficiency of 83.80 %) and S 2 O 8 2- (maximum conversion efficiency of 70 %) in an electrolytic reactor, and the regenerated (NH 4 ) 2 S 2 O 8 could be recycled for gas purification to extend the service life of the oxidant. Consequently, a complete conversion cycle of S and N species was obtained, and its conversion pathways were proposed. After several cycles, the SO 4 2- and NO 3 - enriched in the solution were post-processed into a compound fertilizer, thereby partially recovering the economic cost.